The egg, the chicken, and evolution

A question from formspring.me:

“Who came first, the egg or the chicken?!”

The egg, of course! Reptiles were laying eggs before the first bird was even around. Now, if you’re specifically talking about a chicken egg, it gets a little more complicated. I was going to create my own explanation, but I think Wikipedia already does quite a nice job:

Since DNA can be modified only before birth, a mutation must have taken place at conception or within an egg such that an animal similar to a chicken, but not a chicken, laid the first chicken egg.[8][9] In this light, both the egg and the chicken evolved simultaneously from birds that were not chickens and did not lay chicken eggs but gradually became more and more like chickens over time.

However, a mutation in one individual is not normally considered a new species. A speciation event involves the separation of one population from its parent population, so that interbreeding ceases; this is the process whereby domesticated animals are genetically separated from their wild forebears. The whole separated group can then be recognized as a new species.

The modern chicken was believed to have descended from another closely related species of birds, the red junglefowl, but recently discovered genetic evidence suggests that the modern domestic chicken is a hybrid descendant of both the red junglefowl and the grey junglefowl.[10] Assuming the evidence bears out, a hybrid is a compelling scenario that the chicken egg, based on the second definition, came before the chicken.

There you go – a scientific answer to an age-old question! Of course, the Biblical viewpoint is that the chicken came first, since God created birds on the fourth day and made no mention of eggs. Guess proving the Bible wrong again is the cherry on top.

Kangaroo rats!

Right now I’m about to give my talk at Evolution 2010. Don’t worry, I’m not blogging instead of practicing – I made this post a while ago. But I figured it would be appropriate to share some love for my study organism, the kangaroo rat! And what better way to do that than a David Attenborough clip:

That’s a different species than my particular k-rat: I study banner-tails, which are totally cuter with their fancy tails. For more information and photos, check out one of my previous posts about my research! Or just look at this cute little baby:

Religious accommodationism at Evolution 2010

Amongst evolutionary biologists, there are differing opinions on how to communicate science to the public and increase acceptance of evolution. One of these opinions is religious accommodationism, which attracts much ire from more outspoken activists such as PZ Myers and Jerry Coyne. While I happen to agree with them, I do understand not everyone does. There are those who believe science and religion are totally compatible, that theistic evolution is good enough, and that we need to mince our words lest we offend liberal theists who could be on our side.
However, I was surprised to find a whole 2 hour symposium at the Evolution 2010 conference devoted to accommodationism. It was the Communicating Science Symposium, which started with a talk by Robert T. Pennock on Communication Evolution, focusing on audience and message. You all know my love for evolution and communicating it to others, so I was initially very excited for this talk. It definitely had good parts, especially about carefully choosing our wording as to not confuse others (Don’t say you “believe” in evolution, don’t call it “Darwinism,” don’t say you have “faith” in science, etc).

But it quickly went downhill. Much of the talk was about distancing support of evolution with atheistic views – that we need to stress that religion and science is compatible so people in the “middle” can still accept theistic evolution. That people are more willing to accept evolution if they hear it from their pastor. He lauded Francis Collins and the BioLogos foundation for being pro-evolution…even though BioLogos just had a piece trying to reconcile Biblical Adam and Eve with evolution.

That’s why there’s a problem with accommodationism. It’s more about winning numbers for your cause than truly communicating and educating people about evolution. Are people truly supporters of evolution if they’re not accepting it as a natural process? Do people really understand natural selection if they think God is zapping in mutations or had a plan for humans to eventually evolve? Why is it that our tactic involves people preserving their religious beliefs (which are based on faith), but molding science (which is based on facts) to fit their world view? If anything, it should be the other way around. Religion should have to accommodate science.

The reason why people feel compelled to do this is because religion holds a special status in our society where it can’t be criticized, even when it’s blatantly wrong. This really came out in the second part of the symposium, which was by a woman from AAAS (I unfortunately missed her name). She said there’s no use in including creationists or atheists in the discussion because we’re extremists who won’t change our minds.

Yep – we don’t want to potentially alienate theistic allies, but it’s totally okay to ignore those atheist extremists. Why is theism worth accommodation, but secular opinions are not? I commented on this in the Q&A, saying if they’re accommodating religion they should also accommodate secular opinions, but all I received was an awkward “Okay” and the Q&A ended – where every other question got a long reply.

I guess it’s just disappointing seeing such a one sided representation of “communication” at a large conference. Should have spent my morning going to the research based talks.

Twitter affects brain chemistry the same as love

Why is Twitter so addictive and appealing? It seems the answer may be more scientific than one would have guessed. An experiment by an industrious blogger has found that sending a tweet increases oxytocin and decreases stress hormone levels in the brain. This is similar to the reaction a person has when being in love.

I would love to see this investigated on a larger scale. Is this guy an anomoly, or is this a common experience for tweeters? How does reading other tweets affect us? Are the effects magnified when someone replies to us? Are the thousands of tweets I’ve sent in the last year considered drug abuse?

Hop to it, NIH! Fund this essential research.

Man, binomial nomenclature is naughty!

What happens when biologists try to get nerdy license plates? They get rejected for being potentially inappropriate:

A forest ecologist’s application for a personalized license plate in the state of Michigan has been denied on the grounds that “PINUS” looks and sounds too much like “PENIS.” Marvin Roberson, who works for the Sierra Club in Michigan’s Upper Peninsula, says he applied for the specialized plate out of arborous love for the white pine (pinus strobus in Latin). However, officials denied his request on the grounds that the plate “might carry a connotation offensive to good taste and decency as judged by the Department of State.”

For the sake of appreciating the juvenile humor, I’m going to ignore the fact that the name of a body part is considered offensive in our society. But really, Pinus isn’t the worst genus you could come up with. Arses, Colon, Bugeranus, Enema, Fartulum, Labia, Orgia, Turdus… Hmmm, us biologists haven’t progressed very far past potty humor, have we?*

I’d love it if scientists could successfully sneak in real “dirty” terms if we’re nerdy enough that the DMV doesn’t recognize them. I think a lot of mammalogists would kill for a BACULUM** license plate!

*If you want to see other silly binomial nomenclature, this site has a great database.
**A baculum is the penis bone found in most mammals (but interestingly, not humans). Mammalogists have a strange and amusing fascination with it, partly for scientific reasons, but partly because it’s funny. Seriously, when I went to the Mammal meetings last year, the most popular merchandise at the auction was carved baculum stuff. Scientists, so weird.

Making a biological child for gay couples

“Is there a way to have two people of the same sex have a kid who is biologically related to both? (Either gay or lesbian couples)”

Short answer: Yes! But it’s complicated.

Long-ish answer: Creating a child from same-sex parents isn’t as easy as just combining the DNA from two eggs or two sperm. The main problem is genetic imprinting, where gene expression is modified epigenetically. That just means the actual sequence isn’t changed, but something else is edited, like adding methyl groups or modifying histones (the proteins that help wind up DNA).

And depending on if you’re a mother or a father, you genetically imprint your gametes differently. And since you generally need one functioning copy of these select genes, it doesn’t help to have two female or two male versions where they’re both turned on or off (too much or too little can both be harmful).

While that seems impossible to overcome, science is pretty impressive. Researchers have already overcome this in mice, where two egg cells were used to produce fatherless mice. So yes, it has been done in another animal!

However, who knows when or if we’ll ever see it in humans. There are always ethical concerns when you’re dealing with human subjects, and it’s hard to predict if offspring would be completely healthy using this method. I think you’d have a hard time getting this past a review board since it’s not a necessary medical procedure – same-sex couples don’t need biologically related children, even if it would be nice. But, you never know.

Male antelopes lie to increase their chances of having sex

Replace “antelopes” with “humans” and I think most of us would nod in agreement. But this is the first time researchers have found “intentionally misleading behavior in animals for the explicit purposes of mating.” Ars Technica has a great overview of the study:

The four-year study looked at the behavior of topi antelopes (Damaliscus lunatus) in the Masai Mara National Reserve in Kenya. This area is dominated by a huge number of predators, including lions, cheetahs, leopards, and hyenas, all of which prey regularly on antelopes. When topi detect a predator nearby, they often make snort-like alarm calls.

From February to March, male topi hold small territories through which receptive females pass to assess each male’s mating potential. The authors noticed that, while a female in estrus was on a male’s territory, the male would sometimes emit alarm calls, even in the complete absence of a predator. These false alarms are acoustically indistinguishable from true alarm snorts.

The authors set out to determine whether these false alarm snorts are simply predator detection errors, or if they function to deter the female from leaving the territory in order to secure more mating opportunities with her. The results overwhelmingly supported the authors’ “sexual deception hypothesis.” False alarms almost never occurred without a receptive female on the territory, the onset of the false snorts was highly correlated with a female’s attempts to leave the territory, and, after emitting a false snort, males managed an average of 2.8 extra booty calls.

You may be wondering why females continue to fall for the lies of males. If this behavior evolved, you think females would also evolve to detect lies, right? It boils down to probability and consequences: Lies happen a lot less frequently than truthful signals, and believing a lie has less severe consequences (mating with a less desirable male) than ignoring a true signal (getting eaten).

This questions comes up a lot when you’re discussing dishonest signaling, which actually happens more than you would think in nature. One of the more popular example is bluffing in fiddler crabs. Sometimes when a fiddler crab loses its enlarged claw, it will grow back a weaker, cheaper claw. While these claws aren’t as good in fighting, they’re just as good at intimidating other crabs. It’s not worthwhile for crabs to check and see if another crab is bluffing, because the consequences of the signal being true are so large (getting the crap kicked out of your crabby self).

Still, it’s very interesting that they’ve now documented this type of bluffing specifically in regards to sex. I have a feeling we’ll see more examples of this in the future, now that researchers will be keeping their eyes open!

(Via Carnal Nation)

Who needs God when you have biologists?

Yes, I’m being very sensationalist – but this still freaking awesome. Craig Venter’s research team has officially created the first artificial organism. The complexity of this endeavour is mind boggling – a genome isn’t a simple thing – which makes this very technically impressive. But in addition to being able to say “Look what we can do!”, this also has a number of large implications for future projects. Now that we can make our own genomes, we can create artificial organisms specialized for fuel production, insulin production, etc… How neat is that?!

PZ has a more scientific summary, and Jerry Coyne has a very good “quick guide” for the not so biologically inclined readers.

I do like Coyne’s response to those that are wondering if biologists are “playing God”:

But what creationists cannot get around is the increasing demonstration that life is merely an immensely complicated chemical reaction. Venter’s team made a genome able to direct and support life using off-the-shelf nucleotides and some other reagents. Eventually, in a few decades, they’ll be able to make a fully living bacterium in the same way. And then we will have played God, at least the way religious people mean it. …Life is just complex chemicals—nothing more, nothing less.

Biology is awesome*!

*Obviously not a biased statement.