I and a diverse group of people got a question in email, one that we are supposed to answer in a single sentence. The question is,
What is evolution?
You know, Ernst Mayr wrote a whole book to answer that question on a simple level, and I’m supposed to have the hubris to answer that in one sentence? OK, knowing full well that it is grossly inadequate, here’s my short answer:
Evolution is a well-confirmed process of biological change that produces diversity and coherent functionality by a variety of natural mechanisms.
Go ahead, you people try to answer it in one sentence in the comments. It’s harder than it looks, especially since I feel the itch to expand each word into a lecture.
By the way, when I say this question was sent to a diverse group of people, I mean a diverse group of people. One of them was the author of this book, and another was from this site, and you can imagine what their answers were. (Sorry, they were sent out with some expectation of confidentiality, so I can’t tell you them. Maybe they’ll notice all the traffic to their websites and share it with us.)
A change in allele frequencies over time in a population.
Evolution is the historical and present natural development of life on this planet and the scientific description of these processes.
Evolution is the historical and present natural development of life on this planet and the scientific description of these processes.
mechanism responsible for the diversity and function of life as a natural phenomenon.
Just “Change”. Originally, used by Albrecht von Haller to describe the “unrolling” of an embryo. Darwin didn’t use the word until 1872. Now, it’s extrapolated to mean “Change”, whether biological or not…
Evolution is the accumulation of mutations resulting in heritable traits, and acompanying fixation of those traits in populations over time.
descent with modification.
seems to me that this was once put forward as the definition, like e=mc^2 its strength is in the brevity.
Evolution is the process of natural selection acting on random variation within a population, which in the long term gives rise to new species by purely natural processes.
I’m going with this:
Evolution is the gradual change and diversification of kinds of living organisms.
If I get a second sentence, I’ll add:
Biologists believe that all modern organism diversity is a result of evolution.
I’m ready to defend what I included and what I left out, but the assignment did not ask for a lecture.
PZ – just write a whole book as a single run-on sentence (with parenthetical examples). After all, you never said that the person indicated a word limit.
Evolution is the observed change, over time, of living things in response to the selective pressures of their environments and the consequent differing developmental expressions of their genetic makeup, along with occasional random mutations.
Reality.
Leon Lederman (physicist and Nobel Laureate) once suggested (tongue-in-cheek) that the ultimate goal of physics was to explain the universe by means of an equation succinct enough to fit on a T-shirt. Richard Dawkins replied, regarding evolution:
“Life results from the non-random survival of randomly varying replicators”
I have yet to find a better or more succinct explanation of evolution.
Whatever sentence you choose, I think it needs to include some reference to heritability.
The snappy version (#6) is definitely good for a quick comeback. For a longer form, I’d go for:
“Living things reproduce, their offspring are like their parents but not identical to them, and not all of the offspring survive, and so over time populations of living things change.”
I think that gets the phenomenon and the mechanism quite neatly. Modelled on this:
“[These laws, taken in the largest sense, being] Growth with Reproduction; Inheritance which is almost implied by reproduction; Variability from the indirect and direct action of the external conditions of life, and from use and disuse; a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less-improved forms.”
By a Mr. C. Darwin, who put it quite nicely, within the very generous Victorian standards of what constitutes “one sentence.”
Okay, the Dawkins version is pretty snappy :)
I think it’s a mistake to include mutation and natural selection in a definition of evolution. These are mechanisms whereby evolution is brought about, but they are not evolution itself. If we discovered that there were other processes that caused biological change over time, or even (this being science, after all) that the whole paradigm of natural selection was wrong, this wouldn’t force us to find some new word to describe what we now call evolution, any more than we need to use a word other than evolution when discussing Lamarck.
I like gingerbeard’s answer, which is short and to the point.
The minimal definition of evolution is ..
The truly shocking thing is how many believers in evolution get it wrong. Unfortunately, that includes you PZ. Two of the absolutely essential features of any definition of evolution are: (1) it requires permanent genetic changes and (2) it is populations, not individuals, that evolve. Both of these restrictions are missing from your definition.
What this means is that there are lots of things covered by your definition that do not fit into the scientific definition of evolution. I’ll leave it to your readers to come up with a list of such changes.
Evolution: The observed fact that the genetic makeup of populations of organisms (the gene pool) changes, over time (evolves).
(The ‘Theory of Evolution’ explains how.)
Evolution is a process of gradual accumulated change.
I take it we are talking about evolution in general and not just the evolution of species (social evolution, economic evolution, political evolution etc).
Slightly improved:
Evolution is a well-confirmed process of well-confirmed biological change that produces well-confirmed diversity and well-confirmed coherent functionality by a well-confirmed variety of well-confirmed natural mechanisms.
Interesting that everyone jumped to the specific Biology definition. My dictionary has: 1. any process of formation or growth; development.
I always liked “descent with modification” but I think the word needs to be wrested from the hands of those who would make it into some sort of “general algorithm” – that’s the point where people stop doing science and become annoying – so I’m going with “descent with HERITABLE modification IN BIOLOGY, YOU MORON (ALL NATURAL, NO JESUS!!!).”
I heard Dawkins define it one time as: The non-random differential survival of randomly varying genes.
You’re right though, the urge to elaborate is strong.
@17 I wouldnt be so quick to call people wrong. You sound like a douche bag. PZ’s definition is broad, along with many others.
The definitions that only refer to life are a bit limited. I work with evolutionary algorithms, and evolution can describe any variable population of individuals with heritable traits who distribution changes over time. Anything from designs of chairs to radio antennae to doormats can be evolved.
The thing I don’t like about Dawkins’ definition is that it implies that survival is always non-random, which it isn’t.
Evolution is the solution when engaged in interlocution about what put stunted willows in the Aleutians.
Evolution is ‘God’s gift’ to atheists.
Ok. IANA BioMajor, but here goes: *deep breath*
Evolution: The process by which heritable changes in individual organisms in a population gradually propagate through that population when those changes are proven, by means of natural selection, not to be detrimental to the survival and reproductive viability of the organism.
“Evolution is the scintifically-confirmed process by which new species arise and by which change occurs within species; evolution occurs via random mutation, natural selection, and other processes.”
I hope semi-colons are legal.
Well, you’re going to be a bit broad brush if you’re trying to sum the whole thing up in one sentence! How about:
The process of genetic change within populations over time in response to their biological and physical environment?
Evolution at any scale (from the microscopic to the galactic) is the the progression (following dumb mathematical laws) from old forms to new forms, sometimes with changes in complexity as well.
(This definition has the advantage of covering evolution in the chemical, biological, psychological, and stellar realms of study.)
Evolution: Better than “goddidit”, because it’s real.
Thanks to prions and such, I’m not so eager to talk about “allele frequencies”, but here goes:
Evolution is the well-confirmed process by which successive generations of replicators change their characteristics over time, prominent components of which include the random variation of heritable traits and the differential survival of some variations over others.
Evolution is the observed phenominon of changes in biological lineages through both short and extended periods of time, as well as a collection of scientific theories that account for the observed changes at levels ranging from morphological observations in the fossile record, to molecular structures observable in the laboratory and through phylogentic comparisons.
CalGeorge @ 20 Yes, but is it well confirmed?
*quickly ducks behind internet*
Cheers,
Ray
That which is discussed in Mayr’s book.
regarding #32, prions don’t evolve.
Based on the linked post, a cross species prion may catalyze the misfolding of related prions in a new host, sometimes with reduced efficiency. Prions harvested from the new host will be genetically derived from that host (different AA sequence in most cases, though highly similar) and so be perhaps more efficient at producing prion desease in that host. No magic at all. The question of efficiency at catalyzing a misfolding cascade may not be one of structural efficiency but evasion of host defense against foreign epitopes. Hope that helps.
Evolution is God’s sketching pad :-p
Easy:
Evolution is a film starring David Duchovny.
My one-sentence definition on evolution:
Evolution is the biological theory that postulates that various types of living things have their origin in other pre-existing types and that the distinguishable differences are due to modifications in success generations.
OK, Larry, what if I tweak it a bit:
Evolution is a well-confirmed process of biological change that produces heritable diversity and coherent functionality in populations by a variety of natural mechanisms.
The answer to the ultimate question about life, the universe and, you know, everything …
… Well it beats 42
The extraction of a mathematical root.
Evolution is a process that occurs over time whereby, ideally, the most fit species propagate and diversify.
Evolution: it’s what’s for dinner. (alternately: “Evolution: the other white meat”)
just kidding.
Evolution is the process through which selective environmental, predatory, and other pressures augment or diminish the survival of random genetic mutations, giving rise to genetic diversity and speciation.
Do you still kick your dog?
Evolution is the differential survival of replicators over time, by processes of mutation, reproduction, and environmental interaction.
Fairly complicated.
The question neither infers nor implies biological evolution. As a result only a few of the comments have unbiased answers.
PZ,
I’d leave out the “well-confirmed.” It has no place in a definition. I’m not arguing that evolution is not well-confirmed, but that its confirmedness does not define it. Even if there were no evidence whatsoever for evolution, the definition would not change.
Besides, it makes you look defensive. How can you be supreme squid overlord when you’re being defensive?
Wade– No, Im not familiar enough with prions to put Bartzs presentation into the right words, but different prions with different disease outcomes evolve in genetically identical organisms.
Evolution is everything that relgion opposes.
Evolution is the reason why there is racism and genocide and war and crime and prostitution, all of which began in 1859.
easy.
evolution is the natural process whereby the gods lost their sex organs.
also: orgies with 10 similarly beautiful women.
It’s not mine, but it’s a classic:
“Evolution is a change from nohowish, untalkaboutable, all-alikeness, to a somehowish and in-general-talkaboutable not-all-alikeness, by continuous somethingelseifications, and sticktogetherations”
Hmm. That is like someone requesting a one sentence description of gravitation.
What would one describe, the basic phenomena (“attracting masses”), the basic definition (“gravitation is a process that results in a mass giving acceleration in a test mass”), the process (“massenergy tells spacetime how to curve, and spacetime tells massenergy how to move”), or the current theory (Einstein’s field equations)?
Considering the audience I would go for the basic phenomena (“heritable changes”) instead of a basic definition (“evolution is a process that results in heritable changes in a population spread over many generations”, or “descent with modification” for short).
“Evolution is the change and diversification of organisms over generations” sounds good to me, cribbing from ACW’s answer.
Hmm. That is like someone requesting a one sentence description of gravitation.
What would one describe, the basic phenomena (“attracting masses”), the basic definition (“gravitation is a process that results in a mass giving acceleration in a test mass”), the process (“massenergy tells spacetime how to curve, and spacetime tells massenergy how to move”), or the current theory (Einstein’s field equations)?
Considering the audience I would go for the basic phenomena (“heritable changes”) instead of a basic definition (“evolution is a process that results in heritable changes in a population spread over many generations”, or “descent with modification” for short).
“Evolution is the change and diversification of organisms over generations” sounds good to me, cribbing from ACW’s answer.
Evolution is a change in populations over time, in which populations adapt to their surroundings, and diverge into different species.
I will admit that that is really two (or three) sentences stuck together. The more concise (but less explicit) version would be to cut it off at the first comma.
Of course, for conciseness, Gingerbeard has it down. “Descent with modification”: one cannot get better than that. The only problem is that it borders on opacity to the uneducated — although I imagine that most of our responses to that question would do so.
I agree with those that would keep details about evolutionary processes and materials (natural selection and genes, to name two big players in each respective game) out of the definition. Evolution is a stronger concept than any one example can show.
I would also point out that Darwin did in fact use the word “evolution” in the Origin — or a form of it, but in its modern sense — as the last word of the last sentence. I will defer to historians of science as to how much that influenced the usage of the term.
Ahem!
What you guys said.
That was easy…
The genetic definition is the best in one sense. Even diehard YEC can’t argue that allele frequencies in a population don’t change over time.
But of course that is not the sense that most people find evolution find controversial, and focusing on alleles doesn’t address that.
The truth is that biologists need multiple definitions to handle the multiple senses in which evolution is used. As in:
1. a change in the frequency of an allele within a population
2. the sum of all genetic change within a population over time
3. the ongoing, dynamic interaction between a population’s genome and it’s environment
4. the large-scale patterns of change in the living world produced by evolutionary processes
Evolution is when a banana has sex with an orange, making a monkey that turns into a man over time, so why are there still fruit and monkeys?
Oddly enough I find this very reminiscent of a famous Jewish story.
Your response puts you in the role of Hillel, you just need to add “Go and study”.
Mrs Tilton @ 53 No, substitute your word Evolution for
religion and the sentence and insanity is complete and to
the blatant point.
Evolution is the observation observation that the diversity of living things is the product of descent with modification.
Natural selection is process by which the differential survival and reproduction of variants in a population results in a net change in the phenotype of the descendant populations.
Or, shorter form:
Evolution = nobody looks exactly like their parents.
Natural Selection = nobody looks exactly like their siblings, either, and it’s a dog-eat-dog world out there, so use the traits that Nature gave you.
Behe @ 59,
The monkeys are obviously still there because they are needed (in large numbers) to work the typewriters. As for the fruit – well, the monkeys have got to eat, no?
The essential elements are: random change, reproduction, non-random selection. PZ’s first attempt in the post left out the random and reproductive bits.
“Survival of the fittest accumulates random mutations to yield large-scale diversity after many generations”
Well, something like that, anyway :).
PZ, don’t you think it’s a bad idea to include “well-confirmed” in the *definition* of ‘evolution’? I mean, wasn’t evolution happening long before it was well-confirmed (which it now is)? Do you really want evolution to be well-confirmed *by definition*? If so, we’re not really saying anything when we say that evolution is well-confirmed.
Again, what would you scientists do without us philosophers watching your backs? (Oh yeah, science.)
Yes, that is why the common or Moran’s definition is good, and why Dawkins’ fails.
The same goes for a minimal definition of gravitation, for example. It is the duty of a theory and its descriptions of observed mechanisms to flesh out and fulfill the definition. For example, how much acceleration a mass will give to a test mass.
I would certainly use the definition in describing the phenomena elsewhere. But IMHO it is more informative and catchy to try to describe the process here.
Probably not, considering the audience. But there is confusion in that there isn’t any reason to let a basic definition of a process exclude similar processes; it should be short, general and inclusive. It is, as I observed above, the (natural) task for a theory to exclude other processes.
The theory of evolution is about biological evolution, and for example genetic algorithm software will not exhibit all the mechanisms and other phenomena associated with biology. At least not yet.
Similarly to a basic definition of evolution, or the process of life as a population knows it, one can make a consistent definition of a living (individual) organism:
Note that this is also inclusive, so multicellulars, unicellulars, viruses, plasmids and other evolutionary elements can be included as soon as they have individual histories, as well as software if you wish.
Yes, that is why the common or Moran’s definition is good, and why Dawkins’ fails.
The same goes for a minimal definition of gravitation, for example. It is the duty of a theory and its descriptions of observed mechanisms to flesh out and fulfill the definition. For example, how much acceleration a mass will give to a test mass.
I would certainly use the definition in describing the phenomena elsewhere. But IMHO it is more informative and catchy to try to describe the process here.
Probably not, considering the audience. But there is confusion in that there isn’t any reason to let a basic definition of a process exclude similar processes; it should be short, general and inclusive. It is, as I observed above, the (natural) task for a theory to exclude other processes.
The theory of evolution is about biological evolution, and for example genetic algorithm software will not exhibit all the mechanisms and other phenomena associated with biology. At least not yet.
Similarly to a basic definition of evolution, or the process of life as a population knows it, one can make a consistent definition of a living (individual) organism:
Note that this is also inclusive, so multicellulars, unicellulars, viruses, plasmids and other evolutionary elements can be included as soon as they have individual histories, as well as software if you wish.
Evoloution mean change over time.
The fossil record shows us that life has changed significantly over time with a general trend of increasing complexity.
Evoloutionary biology is the study of the natural processes by which these changes came about.
Differential selection among replicating replicators in response to a selective gradient.
So why are there still AYATOLLAHAS and POPES?
Living things have easily observable variation due to the presence of different alleles, generated by random mutation, necessarily resulting in some individuals being better adapted to their environment, and in some cases able to exploit new resources, which necessarily allows those individuals to reproduce faster, eventually dominating the population.
I think this sentence has the advantage of explaining how evolution works specifically, while arguing that it must be true. It seems to require a second sentence to explain speciation.
Jumpin’ Jeezus!, from ‘this book’ …give you a Biblical understanding of God’s care and provision for HIS animals…
‘His’ animals goddam eat each other! Idiots!
“Descent with modification” seconded (or thirded or whatever). The basic fact of evolution needs to be kept as simple as possible – you can flesh out the details in the theory.
People only really make natural selection into a “general algorithm”, so far as I’m aware. And it seems to me such a move is justified wherever you have imperfect replicators with differential reproductive success and limited resources.
Chance sifted.
I have still to read the referenced paper, but this raises a series of questions to this layman:
– This sentence seems to describe differential reproductive success of the misfolding in its current environment. The post claims that this adaptation (of the misfold) indeed happens over time. How is that not selection and adaptation?
– The mechanism of “variation” is AFAIU sourced by host variations of prion proteins. But isn’t environmental sources for mutations allowed?
– I assume from the descriptions that it is the misfold that is the evolutionary element with independent lineage here, the evolving “organism”. The prion protein itself is just the carrier, as a cell can be a carrier for a virus. As a virus undergoes changes during infection, is it a problem for an evolutionary description that the misfold induces a slightly different misfold of another protein when jumping the species barrier or when and if the host produces variations of the prion proteins?
I have still to read the referenced paper, but this raises a series of questions to this layman:
– This sentence seems to describe differential reproductive success of the misfolding in its current environment. The post claims that this adaptation (of the misfold) indeed happens over time. How is that not selection and adaptation?
– The mechanism of “variation” is AFAIU sourced by host variations of prion proteins. But isn’t environmental sources for mutations allowed?
– I assume from the descriptions that it is the misfold that is the evolutionary element with independent lineage here, the evolving “organism”. The prion protein itself is just the carrier, as a cell can be a carrier for a virus. As a virus undergoes changes during infection, is it a problem for an evolutionary description that the misfold induces a slightly different misfold of another protein when jumping the species barrier or when and if the host produces variations of the prion proteins?
Slight modification, not wishing to sound Lamarkian.
Evolution is the differential selection, as a function of a selective gradient, among randomly varying replicating replicators.
@17 If you tally up the responses of the sixteen prior to your post, the majority do meet the major points you posted. As Bugs would say: “What a Moran.”
I like Darwin’s comment about “Heredity (which is almost implied by reproduction).” Self-reproduction has to mean producing offspring _like yourself_, so inheritance is implicit there. Descent with modification really does capture the heart of it. Decorating it with mutation (one mechanism of variation, not the only one) and natural selection (one mechanism of filtering, not the only one) is superfluous until you get beyond sentence 1.
In fact, I’d even cut down my earlier suggestion in #14 to this:
“Living things reproduce, their offspring are like their parents but not identical to them, and so over time populations of living things change.”
@Holbach,
Mrs. Tiltons’ post was satire… go read her website. Most entertaining.
Evolution is the result of random changes in the order of nucleotides producing heritable differences between members of a population, and it is the process by which inherited traits that confer upon their possessor slight advantages in survival and/or reproduction are passed on to the next generation in greater measure than inherited traits that do not confer such advantages, so that any given generation of any given population is ever so slightly better adapted to its environment than the generation before, with the result that over exceedingly long periods of time (too long by several orders of magnitude to be observed in a laboratory setting and not completely observable in the fossil record due to the rarity of the conditions needed to create fossils, which means the ‘microevolution’ observed to occur over short periods of time is usually considered proven fact while the ‘macroevolution’ that occurs over millennia is debated), populations that began with identical gene frequencies and that live in differing environments end up with such different gene frequencies that a member of one population is no longer capable of producing fertile offspring with a member of another population, at which point the different populations are more accurately termed different species.
To all my English teachers who told me run-on sentences are bad: Take THAT.
Never mind, I believe I can answer that one myself.
Yes, it is a problem. The adapted misfold will not take its change to the next host organism. So yes, a more infectious misfold will spread through a population of hosts provided that the hosts produce the variations with some probability.
As it is, the misfold isn’t independently evolving. Sorry, ERV (and Bartzs), I will now need some more convincing before accepting (misfolds of) prions as organisms.
But I have still to read the research.
Never mind, I believe I can answer that one myself.
Yes, it is a problem. The adapted misfold will not take its change to the next host organism. So yes, a more infectious misfold will spread through a population of hosts provided that the hosts produce the variations with some probability.
As it is, the misfold isn’t independently evolving. Sorry, ERV (and Bartzs), I will now need some more convincing before accepting (misfolds of) prions as organisms.
But I have still to read the research.
ERV, continued sidebar on prions: prion particles are never pure. They can incorporate other cellular detritus, for instance peptides from degraded actin, To the extent that prion particles of altered composition recruit “same” structural elements to “crystallize” out and create a pathological state, more stable, thus more pathological and more endurable pathogens can evolve. There are reasonable arguments to support such a model but quality characterization of prion particles, especially of components present as sub-stoiciametric levels is very very challenging. The advantage of this model is it is far more mundane than invoking just prion protein structure for variant pathogenicity.
Evolution makes sense.
ID does not.
Creationism = mythology.
See, it’s easy! ;-)
Evolution is a well-confirmed process of biological change that produces diversity and coherent functionality by a variety of natural mechanisms.
You got it right. Evolution involves both process (change over time) and mechanism (what causes the change).
As Gould correctly pointed out, the process is FACT but the mechanism is THEORY.
Neo-darwinism is a MECHANISM and can be described as an unsupported theory.
To conflate both PROCESS (FACT) and MECHANISM (THEORY) into the same package is irresponsible, disingenuous and down right fraudulent.
Intelligent design is a MECHANISM of evolution and has as much right to be considered as darwinism.
You can easily believe in both evolution AND intelligent design. Just ask the billions of catholics, jews, protestants and muslims who do.
I tend to go for “descent with modification” whenever this question comes up. Admittedly, it’s not a very good one, but if the interlocutor is sharp enough all the repercussions of evolution become very clear in my experience.
“Evolution is the change in the genetic makeup of a population over time.”
It’s a phenomenon, not a process, and there really should be a little more rigor in defining it. Otherwise the “theory of evolution” bleeds into the fact of evolution.
The theory of evolution by descent with modification is such a predominant and comprehensive explanation of the phenomenon of evolution that it is often called THE scientific theory of evolution. But even if the theory were overthrown tomorrow, evolution would still happen – scientists would just have a different explanation.
Heredity.
Evolution is random variation tested then replicated.
There is some confusion here between definition, ‘minimal definition’, and what evolution is.
Definitions are typically one sentence and are supposed to guide and/or explain word usage.
What something is is another matter altogether.
Edited from #77, and others.
I believe it to be grammatically correct, recommended for use punishing someone for limiting you to one sentence.
Evolution, a process well-confirmed by biology and paleontology, is the action of natural selection, the process by which inherited traits that confer upon their possessor slight advantages in survival and/or reproduction are passed on to the next generation in greater measure (change in frequency) than inherited traits that do not confer such advantages, upon variation caused by mutation, random changes in the order of nucleotides (alleles) producing heritable differences between members of a population, so that any given generation of any given population is ever so slightly better adapted to its environment than the generation before, with the result that over exceedingly long periods of time (too long by several orders of magnitude to be observed in a laboratory setting and not completely observable in the fossil record due to the rarity of the conditions needed to create fossils, which means the ‘microevolution’ observed to occur over short periods of time is usually considered proven fact while the ‘macroevolution’ that occurs over millennia is debated by IDiots) occasionally speciation, when a population is divided into reproductively isolated populations ending up with such different gene frequencies that a member of one population is no longer capable of producing fertile offspring with a member of the other population, occurs.
Evolution is the process of energy & matter interacting with time.
.
Mrs Tilton @ #53 I retract my comment at #61; I did
read your site and it is good stuff! Being such a staunch
hater of religion, I am unable, and probably unwilling to
recognize satire from sarcasm. I am always ready and
happy to express my opinions on insane religion, sometimes
at the expense of differentiation. Keep that site alive!
Torbjörn, regards #73, ‘misfolding’ is scaffolded much like crystalization is seeded. Take reproduction out of the picture. But proteins misfold all the time and the cell cleans up after itself, or dies. When it dies, other cells clean up after it, or pick up the poisonous structures and die in turn. More stable structures are harder to clean up after. Beyond stability itself, the kinetics of recruiting new material matters. I’ll leave the differential equations to others but repeat the note that prion particles are not pure.
Okay, I don’t have any new defintion, since others have already put it about the same way I would, but here’s my 2 cents worth. Assuming it’s biological evolution (which is what most people mean by evolution, really), I think it depends on the target audience. “Descent with modification” probably is the best, succint answer, but doesn’t help when you’re at a dinner party and trying to give a definition that people will actually understand. In that case, I’d go with something like Stephen Wells first defintion, even if it does hint at selection, which is only one of the mechanisms of evolution:
I also like Thomas R. Holtz’s answer, similar to the above, but closer to the wording I used when explaining evolution to my 8 year old:
Intelligent design is a MECHANISM of evolution and has as much right to be considered as darwinism.
Don’t hide behind the cooling corpse of Gary Gygax as you say that.
Intelligent design has no right to be considered whatsoever, at least not in a scientific context. It can explain everything, and as a result really explains nothing. For example: “on the stroke of midnight, Jan 1, 2000, every being on this planet briefly became a small red apple, and then turned back again”. Intelligent design supports this hypothesis. After all, if the designer, whose motives and powers we cannot understand, had hard-coded this fate for us, it must have happened, however implausible it seems to our science. There is, in fact, no hypothesis I can put forth which will be contradicted by intelligent design – since the designer is not understandable, said designer is capable of doing absolutely anything.
Intelligent design is worthless because it can never be falsified. The theory of evolution by descent with modification, on the other hand, makes predictions which could easily be falsified. One fossil rabbit from the pre-Cambrian, one dog giving birth to a cat, one mammal without bone structure analogous to a reptile’s, and evolution trips and falls. But we haven’t found any of these yet.
I can’t recall at the moment who coined the phrase, and I don’t have it exactly right I fear.
“All we have is a candle in the dark to light our way, and along comes the clergy to blow it out.”
Evolution is the pack of matches that keeps relighting the candle.
Dungeon Inhabitant:
*Sigh*
Go to Panda’s Thumb, look around, learn just how stupid this assertion is and then, if you’ve got the humility, feel free to come back and apologise.
We’re sick of explaining the obvious to trolls here.
Mark @ 87: I wasn’t going to say IDiots. The intellectual capacity of the debaters of evolution is irrelevant to the fact of evolution, and insulting people doesn’t persuade them.
I just thought “debated” needed to be qualified. I’m sure there’s a better phrase to make it clear that biologists are not debating.
Congratulations on actually reading the whole sentence, though.
The adaptation of a gene pool to better suit its environment.
Evolution can be described as a subset of Einstein’s magnificent definition of science.
“Science is the attempt to make the chaotic diversity of our sense-experience correspond to a logically uniform system of thought. In this system single experiences must be correlated with the theoretic structure in such a way that the resulting coordination is unique and convincing.”
Adding the simple phrase; The Evolution of living systems on planet earth is a critical part of the unity of science. “Science is …
This my sound a bit William F. Buckley-ish, but here goes:
evolution is the differential lineal expression of felicitous biological possibility actualized by simultaneously contingent and undirected natural forces.
Evolution is the accumulated changes in structure and function, as seen over time, in the manifold offspring of a species, brought about by environmental pressures, social pressures, and sexual preferences selecting for the most successful organisms.
Your children are different from you, sometimes for the better.
Short and long necked giraffes happily graze in a field until a fire comes along, destroys the grasslands, leaving only one source of food–the leaves in the trees located several feet above the ground.
With the benefit of hindsight after 99 comments… let me suggest… <drum roll>lt;fanfares>lt;confetti rain>
Descent with heritable modification.
That really is all of it. “Descent” and “heritable” each imply reproduction, so it’s already in there twice; it doesn’t need to be mentioned separately. (Omit needless!) Populations don’t really need to be mentioned or implied — a population consisting of a single parthenogenetic female that dies upon giving birth to a single offspring would still evolve with each generation (even though it would do so only by mutation, and perhaps by drift in the gonads). (OK, such a population would actually have a maximum size of 2… so the concept of allele frequency makes sense… but it doesn’t need to be mentioned, as long as we’re in the “omit needless” business.)
This definition is broad enough to allow languages and memes in general, computer simulations/genetic algorithms, and the like to evolve; life should not be mentioned in the definition of evolution. It is at the same time narrow enough to prevent all “change over time” from being evolution — evolution and development is not the same: “stellar evolution” is analogous to development, it is not evolution.
The theory of evolution by mutation, selection and drift should not be mentioned in the definition of evolution, and neither should any part of it. Evolution is what the theory explains, and it’s just one theory of several (Buffon, Lamarck, Lysenko; Darwin himself thought inheritance was lamarckistic; Goldschmidt, Schindewolf, Osborn…), even though it happens to be the only one that hasn’t been falsified yet (ignoring those that aren’t falsifiable in the first place, such as ID by a sufficiently ineffable designer with an inordinate fondness of beetles and way too much time on its hands).
(Did Buffon actually have a theory, though?)
——————
Wrong. The diversity of complexity has increased.
It would, if it were science!
Call them IDologists then. After all, they are ideologists rather than scientists.
With the benefit of hindsight after 99 comments… let me suggest… <drum roll>lt;fanfares>lt;confetti rain>
Descent with heritable modification.
That really is all of it. “Descent” and “heritable” each imply reproduction, so it’s already in there twice; it doesn’t need to be mentioned separately. (Omit needless!) Populations don’t really need to be mentioned or implied — a population consisting of a single parthenogenetic female that dies upon giving birth to a single offspring would still evolve with each generation (even though it would do so only by mutation, and perhaps by drift in the gonads). (OK, such a population would actually have a maximum size of 2… so the concept of allele frequency makes sense… but it doesn’t need to be mentioned, as long as we’re in the “omit needless” business.)
This definition is broad enough to allow languages and memes in general, computer simulations/genetic algorithms, and the like to evolve; life should not be mentioned in the definition of evolution. It is at the same time narrow enough to prevent all “change over time” from being evolution — evolution and development is not the same: “stellar evolution” is analogous to development, it is not evolution.
The theory of evolution by mutation, selection and drift should not be mentioned in the definition of evolution, and neither should any part of it. Evolution is what the theory explains, and it’s just one theory of several (Buffon, Lamarck, Lysenko; Darwin himself thought inheritance was lamarckistic; Goldschmidt, Schindewolf, Osborn…), even though it happens to be the only one that hasn’t been falsified yet (ignoring those that aren’t falsifiable in the first place, such as ID by a sufficiently ineffable designer with an inordinate fondness of beetles and way too much time on its hands).
(Did Buffon actually have a theory, though?)
——————
Wrong. The diversity of complexity has increased.
It would, if it were science!
Call them IDologists then. After all, they are ideologists rather than scientists.
Evolution: heritable continuums of code creating an ever-branching tree of biological existence.
Evolution is … a fun way to yank fundamentalists’ chains.
Change through time.
Slightly longer:
Discernible trends in individual traits that result in differentiation of populations through time.
What is a lineal expression, and why isn’t it linear?
That’s a very good description of (an extreme case of) natural selection. It’s not a definition of evolution.
What is a lineal expression, and why isn’t it linear?
That’s a very good description of (an extreme case of) natural selection. It’s not a definition of evolution.
Evolution is the process of random mutation coupled with natural selection which, over time, adapts organisms to their environment and diversifies them into different species.
There doesn’t need to be any trend in it. It can be a random walk, too — that’s called drift.
There doesn’t need to be any trend in it. It can be a random walk, too — that’s called drift.
Apart from putting the theory into the definition, this requires that “species” actually means anything. Not everyone agrees.
Apart from putting the theory into the definition, this requires that “species” actually means anything. Not everyone agrees.
I would end your sentence with a comma and then just tack on the following: “primary among them natural selection, genetic drift and gene flow.”
“Evolution is an evil and intentional fraud supported by no real evidence and lots of fake evidence, perpetrated by Satan through willing dupes on earth to hoodwink good people into abandoning the Bible and the ways of God and following some pointy-headed smarty-pants with lots of letters after his name.”
Sorry . . . apparently my mother got hold of my computer. And, those words are pronounced “SAY-tan” and “Gaw-duh.”
And “BAAAAA-ble.”
I like Dawkins’s definition. I am going looking for a t-shirt.
A theory that explains how the diverse species of life found on the Earth and in the fossil record can be generated through the process of natural selection acting on successive generations of organisms that reproduce with imperfect fidelity (ie mutation).
The wandering about of allele frequencies in a population; sometimes being forced one way, sometimes drifting off another, sometimes with regard, sometimes without.
Or, Evolution is the collection of theories and hypotheses that seek to explain the genotypical and phenotypical changes, or lack of changes, observed and/or inferred over time in a population.
Evolution is an obvious lie.
You guys have got this all wrong — it is clearly a sentence-writing contest, not an evolution-defining contest. (see http://www.bulwer-lytton.com).
Clearly, the best answer will begin:
On a dark and stormy night, Charles Robert Darwin, his relatively youthful cheeks already adorned with the style of facial hair sometimes called “mutton chops,” and sometimes (especially in the United States of America) called “sideburns,” though his chin had not yet been allowed to produce the full beard we know so well from the quintessential, not to say defining, photograph taken late in his life, sat awake contemplating (having found neither sleep, nor reading, nor writing practicable in the wildly erratic pitching and rolling of The Beagle, aboard which he improbably found himself) of all things, the beaks of finches, and more particularly and more specifically the variations in those beaks which he had observed and had carefully, nay, meticulously, documented in his journal, the meticulousness springing, no doubt, from the effusive, yet perplexing, variations in finch-beak shape that had initially puzzled him to so great an extent as he moved methodically from island to island in the South-Seas Galapagos, observing (and journalizing) difference, but seeking commonality — an explanatory cause, if you will — that only now, amidst the agonized, late-night groanings and creakings of the storm-tossed ship around him, amidst the frequent distractions of sailors (who must by now be soaked to their skins, their duties and their positions not entitling them to the dry, if not exactly warm or cozy, cabin in which Darwin was cogitating), tars who were scrambling to trim sails as the helmsman dictated, and above all, amidst and against what, as a boy, the young Charles Robert had learned from innumerable Bishops (including Archbishops), Rectors, Vicars, Prebendaries, Canons, Priests, and Deacons who had told him (not always consistently) what the Bible said, and who had averred throughout his youth and early manhood (indeed, still averred) that the very “creation” that can be observed around us implied, suggested, even demanded a “creator” of the same — that only now were beginning to coalesce within Darwin’s curious and contemplating mind into the glimmerings of an explanation, the outlines of an hypothesis, the suggestions for many studies, and indeed the early foundations of a theory, in fact, the theory that would explain the variation in finch’s beaks and so much more when, (under pressure from the almost equally insightful, if not, perhaps so prescient, Alfred Russel Wallace) Darwin seemingly reluctantly published it in 1859, and when, after fierce opposition from the religionists like Samuel Wilberforce and even fiercer defense from Thomas Huxley (yclept “Darwin’s Bulldog”), after confusion surrounding the rediscovery of Mendel’s garden-pea studies, after intense scientific debate in the 1920s and 1930s accompanied by intense and fruitful research that ultimately overcame Mendel-vs-Darwin doubts and ultimately resulted in the so-called “Modern Synthesis,” a synthesis that has only been confirmed throughout subsequent decades and decades of discovery — discovery including genes, x-ray crystallography, the structure of DNA, PCR, genome elucidation, and indeed, the whole of molecular biology, and a “Modern Synthesis” that can perhaps best be succunctly summarized as:
Evolution: What your parents were helping to perpetuate (in the short-term) when you walked in on them that morning.
Evolution: the art of cousinage.
PZ – just write a whole book as a single run-on sentence (with parenthetical examples). After all, you never said that the person indicated a word limit.
Garcia-Marquez did that. Most frustrating bed-time book ever.
Ric [29], I’ll give you semi-colons but you don’t have to hyphenate when you have an adverb ending in “-ly” modifying an adjective. Just say, “scientifically confirmed.”
I like the “observed fact” definition. But a lot of them would do just fine, especially when I’m arguing with Creationists who insist on using the definition out of a 30-year-old book that talks about “higher” organisms.
I don’t recall where I got this. It’s been hanging on my wall for years:
Evolution is the process by which organisms diversify in order to harvest energy from sources that lie beyond the reach of their predecessors.
Apart from putting the theory into the definition, this requires that “species” actually means anything. Not everyone agrees.
This is a silly notion, and where academic blah blah blah takes leave of reality. Even a five year-old can see that different species of life exist – there are dogs, cats, fish and dinosaur bones. It’s self-evident. Evolution answers the question of how these diverse species are related and how they are generated.
Evolution is the process by which imperfect replicators diversify and change, thereby taking advantage of new resources and mitigating the damage of various external dangers.
moar liek “evo is change in the distribution of heritable traits” amirite
And i disagree with the idea of using a run-on sentence, when it is possible to use a fully grammatical sentence instead; in fact one may transform the run-on sentence into a grammatical one simply by inserting semicolons and commas paired with conjunctions at the clause boundaries – though a book-length sentence that contained only one independent clause would of course be much preferable to such a beast.
Evolution is…
Do you think such a debate would occur over the definition of Newtonian Mechanics, Snell’s Law, Ampere’s Law, Bernoulli’s Principle, Boyle’s Law, Hooke’s Law, Rolle’s Theorum, Ohm’s Law, Kirchoff’s Law, Carnot’s Theorum, Einstein’s Theories of Relativity, Hohenberg-Kohn Theorem, or Nurgaliev’s law/
Of course not, because EVERYONE KNOW S EXACTLY WHAT THEY SAY!
On the contrary, looking above you will soon discover that there are as many different definitions of evolution as there are people offering them.
This is NOT science, it’s mythology.
This is a silly notion, and where academic blah blah blah takes leave of reality.
You have it exactly backwards. It’s where rigorous terminology (denigrated by anti-intellectuals as “academic blah blah blah”) highlights the fact that the map is not the territory.
There is no logical reason why the biological reality of diversity has to split cleanly along species lines. It’s a folk concept, like “kinds.” Various concepts of species have varying utility depending on context.
Just because a child can tell a cat from a dog doesn’t mean there aren’t other, less clear, examples, such as ring species. And, in any case, even given your most basic definition, just when speciation occurs in the process of evolution can only be determined in hindsight.
“This is NOT science, it’s mythology.”
Oh, goodie! Some fun at last.
“On the contrary, looking above you will soon discover that there are as many different definitions of evolution as there are people offering them.”
Hmmm. I wonder how many definitions of “God” there are?
Wikipedia
http://en.wikipedia.org/wiki/Scientific_laws_named_after_people
has a list of Scientific Laws, Principles and THeorums named after the persons who formulated them.
Note the absence of Darwin;s Theory of Evolution, without which nothing in science should make any sense. Hmmmmm….
Somebody has physics envy.
And you’ll note that astronomers went through a similar definitional exercise recently over the term “planet”, but I don’t see anyone calling what they do mythology.
Biological evolution is the process where biological replicators, replicated with unpredictable variation, and undergoing complex environmental selection, replicate with differential success.
I know its cumbersome, but not all variation is genetic or random in the mathematical sense. Similarly selection operates at many levels, including developmental, natural, sexual and artificial.
It always struck me that a more realistic catch phrase was “non-survival of the least fit”. It seems to reflect Darwin’s Malthusian insight better. Selection is a real bugger sometimes and any definition of evolution has to allow for lots of death for the individuals or the whole population.
Speaking of definitions, FreeThoughtPedia has pages on Evolution and Intelligent Design that need updating. Go to their main page (link), click on Help Contribute in the sidebar, read the guidelines and look at Current “works in progress” for a list of the articles tagged as needing improvement.
So which inhabitant of PZ’s troll file is Dungeon Inhabitant? Can’t be Larry Farfarman, this one sounds a bit too sane (but, not intelligent).
So which inhabitant of PZ’s troll file is Dungeon Inhabitant? Can’t be Larry Farfarman, this one sounds a bit too sane (but, not intelligent).
It’s Charlie showing off his man-crush again.
Hmmmm. I wonder what Wikipedia has to say about God?
Theologians have ascribed a variety of attributes to the various conceptions of God. The most common among these include omniscience, omnipotence, omnipresence, omnibenevolence (perfect goodness), divine simplicity, jealousy, and eternal and necessary existence. God has also been conceived as being incorporeal, a personal being, the source of all moral obligation, and the “greatest conceivable existent”.
Wow! There doesn’t seem to be any consensus!
In that case, I can only conclude:
This is not REALITY! It’s complete bullshit.
There is no logical reason why the biological reality of diversity has to split cleanly along species lines.
Of course not, classification of reality into discrete objects is an exercise of the human mind. But it sure as hell is useful, whether you’re talking about species or whole numbers. You can argue about where to draw the lines, but it’s stupid to try and say that classifying organisms into groups based on relatedness is useless.
Being an economist by trade, and holding a political science degree to boot (both of which are now studied in terms of ‘evolution’), I wonder whether some congruence of definitions is in order:
Economics: the ways in which people gain, maintain, use, and lose wealth.
Politics: the ways in which people gain, maintain, use, and lose power.
Evolution: the ways in which populations gain, maintain, use, and lose heritable information?
Just a thought.
I like your definition, but I’d change it like-a-so:
Evolution: a well-confirmed process resulting in biological changes- including diversity and coherent functionality- by a variety of natural mechanisms.
Evolution: it’s what works.
Well, of course, if Wikipedia doesn’t include it, it must not be true.
Evolution – genetic change in a population over time.
Seems like we should have a chance to vote on our favorite one. What about it PZ (or anyone else), set it up for us? It’s just a curiosity thing…
Evolution is that undeniable “theory” of the origins of life which gives the faithful fits (and maybe even an occasional rash).
The study of variation in living systems
Evolution is that undeniable “theory” of the origins and development of life which gives the faithful fits (and maybe even an occasional rash).
M. le baron @91,
Mrs Tilton @ #53 I retract my comment at #61; I did
read your site and it is good stuff!
No offense taken, and thanks for the kind words about my sadly neglected site.
My own view of religion is on the whole negative, but I’m sure it is more nuanced than your own. That you are so uncompromisingly negative is a good thing, though. Whilst I am willing to concede that religion can have some occasional positive aspects, we need people like you to remind the religious that the burden of proof is always on them.
That’s a very good description of (an extreme case of) natural selection. It’s not a definition of evolution.
Indeed. I took a Socratic approach and went with a possible example of an evolutionary mechanism/process rather than a definition. I suspect a primary reason why we’re getting various definitions in response to the one sentence challenge, is because there are many types of evolutionary processes (e.g., natural selection, sexual selection, genetic drift, gene flow, mutations, recombination, etc.) that can produce changes in the variability of a population over time. Which mechanism one believes to cause this change, likely dictates one’s prefered definition of evolution.
I’m sure if the question was, give an example of evolution in one sentence, we would again see a myriad of examples of evolution.
The example I provided here is one I came up with as a basic example of evolution (or possibly something I read somewhere and can’t remember where) for a college prep biology course I taught once as a substitute instructor.It was the basis for pointing out what I understood to be the two fundamental concepts for Darwin’s evolution theory (i.e., natural selection and population variability).
The example can be elaborated upon by showing how there are various types of evolutionary mechanisms that could explain why we only have long-necked giraffes today (which was the point of the example) and where the short-necked giraffes went. In its original form, I would imagine that this example might actually best describe a mass extinction event (i.e., sudden disappearing of a species that shows up in the fossil record). But one could also describe gene flow, and say something like before time, the two species (short and long necked) evolved apart geographically, but then came together. The two species begin to mate (sexual selection processes kick in), and then perhaps because long necked genes were dominant relative to short necked genes (in accordance with Mendelian inheritance), the long neck genes became more prominent among these interacting giraffe species, which eventually wiped out the short neck phenotype (but possibly a few heterozygous alleles remain in the currently existing giraffe population).
At, any rate, things obviously get quite complicated when we start talking about evolutionary mechanisms, and so its obvious that a simple definition won’t make it clear to the average reader what ‘evolution’ is all about–except basically, a change in the variability of a population over time.
On the contrary, looking above you will soon discover that there are as many different definitions of evolution as there are people offering them.
Yes, and that’s not all! Head to a good tabletop dictionary and look up “set”. Hundreds of definitions, stretching across pages and pages of text! Clearly a word that can be used to mean so many things must not mean anything at all!
Therefore, it’s not language, it’s just mythology.
Also, don’t trot “laws” out here as though they actually meant something. A “scientific law” is a simple quantitative relationship with no statement of the underlying causes or limitations. I can violate Boyle’s Law in my own kitchen – it’s called a pressure cooker.
Evolution: it works, bitches??
Things adept to cope with circumstances.
“I can violate Boyle’s Law in my own kitchen – it’s called a pressure cooker.
Posted by: Glazius”
Pray tell . . . How do you violate Boyle’s law with a pressure cooker?
Looks to me as if a pressure cooker is a fine example confirming the combined gas law, of which Boyle’s law is a part.
Temperature goes up . . . Volume remains the same . . . Pressure goes up.
P1 x V1 / T1 = P2 x V2 / T2
.
OTOH:
http://antoine.frostburg.edu/chem/senese/101/liquids/faq/clausius-clapeyron-vapor-pressure.shtml
kind of a spin off, but more applicable to pressure cookers.
What is evolution:
Evolution is the change in allele frequencies over time.
Everything else makes it a specific version of this definition.
Ok, I have to add:
Evolution is the change in allele frequencies within a group of individuals over time.
It has to be in a group, but can be a different group than a population.
Evolution is not bollocks!
There howz that in 4 words 1 sentence.
Dungeon Inhabitant:
Intelligent Design WAS a proposed mechanism for evolution. It was legitimately (and quite thoroughly) investigated by scientists and found to be completely inadequate a generation before Charles Darwin was born, and was then discarded when a far better alternative was proposed. It has no place in modern science anymore except as a historical footnote.
Now, if Craig Venter should ever succeed in his goal of designing an artificial organism, then intelligent design (small letters) may once again be considered a mechanism for evolution, but only as a specific, limited case in which the designer is known, its properties clearly specified, and evolved by natural mechanisms.
I like #74, Derek’s:
Although I suppose that might also describe a horse-race.
What is evolution?
Google has many answers
http://www.google.co.uk/search?hl=en&safe=off&client=firefox-a&channel=s&rls=org.mozilla:en-GB:official&hs=Nk7&defl=en&q=define:evolution&sa=X&oi=glossary_definition&ct=title
Dear PZ,
If your readers need something to do, maybe they could do a plagiarism search on Spencer Lucas.
He seems to be more of a claim jumper than a copier, so it could be tricky and require access to unpublished thesises. But it would be interesting to see what turns up.
Evolution is the term used to describe the observed process of change and diversification of life, over time.
“Theory of Evolution” seeks to explain mechanisms of observed evolution.
Does anyone else feel that the use of the word “natural” is redundant? Technically, in terms of you can’t argue there is a single mechanism or effect resulting from evolution driven by the sun’s radiation that isn’t purely natural. We are natural, the things we make are natural, Coke cans are natural, nuclear power plants are natural, and even unnatural selective breeding and genetic engineering all the (at present) end result of a completely natural process. Even pollution is, in a painfully convoluted way, natural. So it seems kind of foolish to me to have to say “by a variety of natural mechanisms”; what other mechanism could there be? Is it that we’re forced to pedantically beat religious people over the head with the word “natural”, lest they fill in the space between ‘of’ and ‘mechanisms’ with a mechanism of their own fantasy?
It could be a fun game for us though…add lib chemistry.
———————————————
Evolution is a dapperly-confirmed process of biological change that produces diversity and robot-dance functionality by a variety of Trogdor The Burninator mechanisms.
(EDIT)
Does anyone else feel that the use of the word “natural” is redundant? Technically, you can’t argue that a single mechanism or effect resulting from evolution driven by the sun’s radiation isn’t purely natural. We are natural, the things we make are natural, Coke cans are natural, nuclear power plants are natural, and even unnatural selective breeding and genetic engineering are all the result of a completely natural process. Even pollution is, in a painfully convoluted way, natural. So it seems kind of foolish to me to have to say “by a variety of natural mechanisms”; what other mechanism could there be? Is it that we’re forced to pedantically beat religious people over the head with the word ‘natural’, lest they fill in the space between ‘of’ and ‘mechanisms’ with a mechanism of their own fantasy?
It could be a fun game for us though…add lib chemistry.
———————————————
Evolution is a dapperly-confirmed process of biological change that produces diversity and robot-dance functionality by a variety of Trogdor The Burninator mechanisms.
Not that this is better than anyone else’s, but just to clarify in my own mind what the experts are saying:
Biological evolution is the change over generations in typical, hereditary characteristics of a group of reproducing biological entities.
In one sentence?
“Evolution” is an intellectual litmus test.
Or, at slightly longer length:
“Evolution” is an intellectual litmus test that lets you determine whether you’re talking to someone amenable to reason, or to someone too stupid or close-minded to understand the world around them.
In one sentence?
“Evolution” is an intellectual litmus test.
Or, at slightly longer length:
“Evolution” is an intellectual litmus test that lets you determine whether you’re talking to someone amenable to reason, or to someone too stupid or close-minded to understand the world around them.
According to PZ’s definition, all creationists I know believe in evolution. Thats a ingenious way of sweeping them all into the fold!
“Evolution is:…”
” well-confirmed process” – Creationists aren’t opposed to well-confirmed processes
“of biological change” – Creationists call this adaption within a species and some ID proponents like Behe would call this “natural selection” and in rare cases would even recognize common descent.
“that produces diversity and coherent functionality by a variety of natural mechanisms.”- No problem here to just about all creationists, just look at the diversity in dog breeds!
evolution is a change in gene freqency.
Pray tell . . . How do you violate Boyle’s law with a pressure cooker?
The ideal gas law doesn’t assume the gas is ever going to become liquid, y’see. Or be attracted to itself the way water is. Hydrogen bonding and all.
A pressure cooker works by containing the water vapor produced by boiling and using that higher pressure to keep the water liquid at higher temperatures, much as at higher altitudes and lower atmospheric pressures, water will boil at lower temperatures.
But as the pressure cooker cools off, there’s going to be a sudden and marked decrease in pressure at the same volume when the water vapor condenses again, more than could be explained by the simple cooling of the water vapor.
The pressure cooker isn’t necessary, really. Water vapor on its own violates Boyle’s Law, Charles’s Law, and all the other ideal gas laws, especially at temperatures close to the boiling point – because it’s not an ideal gas.
What’s wrong with:
Evolution is what murdered God.
PoxyHowes should win a literature prize, but I can’t see a definition there…
That’s not a definition. Try again.
Depending on the species concept, there are between 101 and 249 endemic bird species in Mexico.
You mentioned cats — are domestic cats and European wild cats separate species? That depends on the species concept.
Things that seem self-evident often get very wishy-washy once you look at the details.
Are we a different species from the Neandertalers? From Homo erectus? From Flores man? From Paranthropus boisei even? All that depends on the species concept. There are at least 25 of them out there, and none is objectively better than any other. No wonder that some say species don’t exist any more than genera do.
…these are theories and similar models. Indeed there is no such debate over the definition of the theory of evolution. Evolution is the collection of facts that the theory of evolution explains.
Easy, isn’t it?
That’s because it isn’t called “Darwin’s theory of evolution”. It’s called “the theory of evolution”.
That’s simply because it’s not Darwin alone — not even Darwin and Wallace alone. You cannot ignore Dobzhansky, Mayr, Simpson, and Gould, to mention just the most extremely famous ones out of a dozen or two who have made important contributions to the theory of evolution.
That’s not what I said. I have done phylogenetic research myself (currently in peer-review). I said that some people say species don’t exist, and that they aren’t being stupid.
Not bad. Not bad at all.
Sure. They just call it “microevolution” and believe that after a certain number of changes God works a miracle and stops it.
Rather, the ideal gas laws only apply to ideal gases. Because nothing is an ideal gas, nothing ever violates them. They are abstractions, approximations that hold to some degree under some circumstances.
And besides, they (and the reasons why nothing is an ideal gas) are just consequences of the laws of electrostatics and gravity and those of the conservation of energy and impulse. They are not really basic laws of nature the way E = mc2 is.
Any self-respecting deity is too ineffable to be falsifiable.
PoxyHowes should win a literature prize, but I can’t see a definition there…
That’s not a definition. Try again.
Depending on the species concept, there are between 101 and 249 endemic bird species in Mexico.
You mentioned cats — are domestic cats and European wild cats separate species? That depends on the species concept.
Things that seem self-evident often get very wishy-washy once you look at the details.
Are we a different species from the Neandertalers? From Homo erectus? From Flores man? From Paranthropus boisei even? All that depends on the species concept. There are at least 25 of them out there, and none is objectively better than any other. No wonder that some say species don’t exist any more than genera do.
…these are theories and similar models. Indeed there is no such debate over the definition of the theory of evolution. Evolution is the collection of facts that the theory of evolution explains.
Easy, isn’t it?
That’s because it isn’t called “Darwin’s theory of evolution”. It’s called “the theory of evolution”.
That’s simply because it’s not Darwin alone — not even Darwin and Wallace alone. You cannot ignore Dobzhansky, Mayr, Simpson, and Gould, to mention just the most extremely famous ones out of a dozen or two who have made important contributions to the theory of evolution.
That’s not what I said. I have done phylogenetic research myself (currently in peer-review). I said that some people say species don’t exist, and that they aren’t being stupid.
Not bad. Not bad at all.
Sure. They just call it “microevolution” and believe that after a certain number of changes God works a miracle and stops it.
Rather, the ideal gas laws only apply to ideal gases. Because nothing is an ideal gas, nothing ever violates them. They are abstractions, approximations that hold to some degree under some circumstances.
And besides, they (and the reasons why nothing is an ideal gas) are just consequences of the laws of electrostatics and gravity and those of the conservation of energy and impulse. They are not really basic laws of nature the way E = mc2 is.
Any self-respecting deity is too ineffable to be falsifiable.
And thus too ineffable to be worth thinking about.
I’m no biologist, but I’ll take a crack at it.
Evolution describes the changes which occur across generations, being the result of when a population which contains variations also contains individuals which do not reproduce equally.
Or, to use an example:
If the variation in a population describes a bell curve, the evolution of the population occurs when a portion of that bell curve contains individuals which can reproduce at a higher rate than the rest of the individuals within the population, over several generations this shifts the curve.
Needless to say, if selection pressures eliminate some portion of the population, (any selection pressures, including random ones), those individuals do not reproduce at all. But I cover that because clearly a zero reproduction rate is not equal to the reproduction level of the surviving members of the population.
Further, it appears to me that a (hypothetical) population of clones, which doesn’t experiance any individual mutations or genetic drift, will maintain genetic identity and cannot be said to evolve no matter how many generations the population goes through. So, IMHO, population variation is an important part of the definition.
Of course, whether you like my definition or not, I did have the advantage of reading the rest of the attempts and pondering them. So I can’t be credited for what is clearly a very nice group effort.
Evolution is the emergent phenomenon that results from the random alterations of recombining memory systems existing in a changing system.
Fixated alleles, balancing selection, … D’oh! (And I knew that the day before.)
So, okay, that isn’t a relevant objection.
@ wade:
Thanks for your answer!
Yes. But crystals growth isn’t improved (in roughly the same environment).
Hmm. Okay, but I see the misfold as the “organism”. The functional trait would simply be ability to fold other prions. The genetic trait would be the misfold, in topological space.
So, in my view I think you are suggesting that the “genetics” isn’t much like genetics, as the folds aren’t pure if the particles aren’t.
Yes, that would at the very least push the idea further out to the fringes, possibly non-salvageable so. (I wouldn’t know the consequences.)
Fixated alleles, balancing selection, … D’oh! (And I knew that the day before.)
So, okay, that isn’t a relevant objection.
@ wade:
Thanks for your answer!
Yes. But crystals growth isn’t improved (in roughly the same environment).
Hmm. Okay, but I see the misfold as the “organism”. The functional trait would simply be ability to fold other prions. The genetic trait would be the misfold, in topological space.
So, in my view I think you are suggesting that the “genetics” isn’t much like genetics, as the folds aren’t pure if the particles aren’t.
Yes, that would at the very least push the idea further out to the fringes, possibly non-salvageable so. (I wouldn’t know the consequences.)
I like that.
And that too. :-P
I like that.
And that too. :-P
I didn’t come up with “IDologists”, but I forgot who did. :-(
I didn’t come up with “IDologists”, but I forgot who did. :-(
I’ve always liked IDolators.
That looks wrong. I don’t like them. (the capital D kind –I got nothin’ against graven images)
I should say, I admire “IDolators” as a term of abuse for evolution-denying pseudoscientific morons.
I’m not totally happy with my last attempt at a definition-
Evolution: the ways in which populations gain, maintain, use, and lose heritable information.
This challenge has been interesting, to say the least. I am torn between two approaches to the definition. The first is the ‘Descent with (heritable) modification‘ angle, the second is the ‘Evolution describes the process of…‘ angle. My attempted definition above falls into the ‘process’ category; just replace the word ‘ways’.
But I do not think that evolution is a process. A process is a sequence of steps with a result at the end, therefore deterministic. A definition of evolution has to describe the millions of events over billions of years that have been discovered. I think that evolution is a history, not a process; It is descriptive, not prescriptive.
But a history of what? Populations? Groups? Individual organisms? Genes? Exactly what is descending with modification? At the ground level it is ‘replicators’. So evolution is the history of replicators (and more specifically biological replicators). But this definition doesn’t really capture the dynamic of change. More is needed.
How are these biological replicators going about their business of replicating? In essence they are using chemical ‘tools’ to build structures and machines to facilitate survival long enough to replicate. They are employing a sort of technology. So, here goes:
Evolution is the technological history of biological replicators.
It’s not perfect, but remember that I’m just a dumb economist!
ennui wrote, “But I do not think that evolution is a process. A process is a sequence of steps with a result at the end, therefore deterministic.”
I don’t think those of us who see evolution as a process think it is deterministic.
To create an analogy, water freezing in the atmosphere and settling to the earth is a very simplied description of the process of snow. But knowing the process doesn’t mean we can determine ahead of time where the drifts will form.
To continue the analogy, we can make some general statements about where snow will accumulate in greater or lesser amounts. That corner around the house where the wind always picks up speed will have less snow than just beyond the hedge where the air pressure drops. But that’s the everchanging fitness landscape for snowfall, and the general predictions do not always pan out.
Evolutionary theory can be used, like meterological theories, to create a laboratory environment where most essential variables are controlled and the theory can be used to predict the results. If you generate snow in a lab, and control the wind speed, direction, humidity, pressure, etc., you can predict where the drifts will form. That’s close, in my understanding, to how researchers have been able to select for traits, like oil-eating bacteria, which were rare previously.
And like creating snow, the scientists are limited to the original possibilities inherent in an organism. Snow can’t be formed out of sunlight, and cats cannot be formed into dogs.
So I see viewing evolution as a historical record as a limit the application of the theory. True, there is a lot of information available to help refine the theory in the historical record; just like Antartic ice cores help us refine our understanding of meteorology. But the power of the theory is not in it’s explaination of past events, but understanding the process well enough to predict, or even manipulate future events.
My $0.02, from one of the much-maligned engineers. :)
P.S. As an economist, you must be aware of the process of currancy flow. I considered using a comparision of the history of currancy flow with the theories which attempt to explain currancy flow with an eye to predicting the future currancy flow. However, I soon realized I was out of my depth. But, I still think there is a potential comparison to be made there. Maybe, as an economist, you can provide a deeper insight than I can. Cheers.
#25, Derek, remember that in Dawkins’ definition he’s not referring to the survival of individual organisms within each generation, but to gene allies across generations.
While the survival or otherwise of any individual may indeed often be down to circumstances that have no bearing on the quality of it’s genes, the survival rate of any particular gene found in multiple bodies, across the long haul of several generations, can never be put down to purely random luck.
As Dawkins put’s it (although I forget the exact words), any gene in a particular body may fail to be passed on due to bad luck (or bad gene ‘companions’), but a gene that ALWAYS finds itself in bodies that fail to reproduce is not unlucky, it’s a bad gene.
Evolution is the fact, supported by much empirical evidence, that organisms have changed over time, from simple ones at the beginning to more complex ones over time.
That’s all for that definition, now for another.
The theory of natural selection is a model of how the fact of evolution came about.
I just today noted the title of a paper in Science, and thought to myself “That’s going to annoy the biologists”.
“Age and Evolution of the Grand Canyon Revealed by U-Pb Dating of Water Table-Type Speleothems”
(7 March 2008:
Vol. 319. no. 5868, pp. 1377 – 1380
DOI: 10.1126/science.1151248)
But it occurs to me that it would also annoy the Creationists. So there’s that.
Owl,
Probably the only person left on the thread but why would that bother biologists. Evolution means gradual development over time. That certainly applies to the Grand Canyon as it wasn’t created in a great flood or anything like that.
Oh, I just kinda assumed that anything that allows creationists and laypersons to confuses evolution-in-general (gradual development over time) with biological evolution (which I think necessarily includes heredity, as noted above) would be annoying to a biologist.
Each scientific discipline defines and uses terms in a particular specialized way; evolution, while having a specific meaning in biology (and a distinct meaning in cosmology, and I suppose geology and other disciplines as well), is often used by non-scientists to refer to what I suppose might be an overarching idea that the universe, and everything within it, developed gradually over time without the initiation of, or interference from, a deity.
Hm.