It’s easy. If it uses the word “Lamarckian” without boldly prefixing it with “not“, you can just stop reading. Likewise if the word is prefixed with “pseudo-“, “semi-“, or “quasi-“. Just skip it. It’s too confused to bother with.
Epigenetics is in the news again, and in fact, it’s newsworthiness seems to be rising at a fantastic rate. Eight years ago, would you believe, I wrote a short summary of what epigenetics is, driven largely by the fact that a lot of people were writing about epigenetics without acknowledging that it was a grab-bag of mundane regulatory processes. It’s gotten worse. I had to explain the obvious: epigenetics ain’t magic. I tried to explain it last year again, that people have a lot of misconceptions about epigenetics. It’s frustrating because epigenetics encompasses a lot of cool and important stuff — genetic switches and gene regulation and plasticity and environmental responsiveness — but all the popular press wants to talk about is this weird idea that it’s a way break the tyranny of genetics and evolution and modify your genes for future generations, which is just plain wrong.
What it tells me is that there is still a lot of uneasiness about the implications of evolutionary theory. Not among most evolutionary biologists, of course, but in the general population. They wish for a way to believe that their progeny (and themselves) can be enhanced by an act of will, and they think that a poorly understood phenomenon like epigenetics provides a loophole. The whole idea that evolution is a statistical property of populations rather than something they can game to their advantage as individuals leaves them queasy. So they noodle around with the idea that somehow, by practice, they can change their whole genetic legacy using the buzzword “epigenetics”, not even realizing that epigenetic phenomena are a consequence of the properties of proteins, coded by genes, and regulatory sequences imbedded in their DNA, and that even short term cytoplasmic responses in the cell are ultimately derived from information in their genome.
People who use epigenetics as something that is anti-evolutionary remind me of Perry Marshall, the creationist who thinks Barbara McClintock’s work rebuts Darwinism, because he wrongly thinks somehow that it refutes the role of chance in evolution. They hate the whole idea of chance-driven processes, and want a way to shape genetics by an act of will, instead. It’s painful to see the contortions they put themselves through to run away from the implications of evolution and genetics.
One can empathize with them for trying to beat back the IQ-meritocracy
crowd.
They might be taking up the wrong arms, but at least they have the right
target.
I don’t get why people can’t see that epigenetic modifications are controlled by genes in much the same was as any other cellular process. They are not some sort of inconvenient entity that biologists just can’t make fit into evolutionary theories.
In simple terms a section of the genome becomes more or less accessible to transcription machinery based on the actions of proteins which add/remove acetyl (histones) and methyl (@CG’s) groups on chromatin.
There will be signalling molecules, receptors, transcription factors, non coding RNA, DNA sequences and so on that impact the probability that a particular section of chromatin structure is altered. A mutation in any of which could alter the level of epigentic modification at a particular site and be subjected to selection pressure.
Nothing Lamarkian about it.
I’m going to repeatedly climb a tree and jump out of it so my descendants will develop wings.
Making a few assertions to see if I’ve got the right idea about epigenetics and Lamarckianism:
Am I on the right track here?
@moarscienceplz #3:
I’m going to keep moving, so that my descendants don’t turn into trees which your descendants will shit on.
There, that’s my legacy sorted.
reason and science have been pointing out the fact that man is not the “center of the show” for a long time. Earth is not the center of the solar system nor is the solar system the center of anything. We are but late comers to earth and set precariously atop the environment dependent on the whole process being stable or we parish.
We are not the purpose and reason for existence we barely understand what is going on
That some would grasp at any ideas like straws to reinforce the feeling of control and centrality is understandable but futile.
uncle frogy
When I talk about epigenetics with students I like to turn to a musical analogy. Imagine a bit of sheet music say, for a violinist performing in an orchestral setting. The sheet music contains the precise pattern of notes and rests to be performed (that’s the DNA sequence) but above the bars of musical code are often annotations such largo, tempo, adagio, forte, etc. Those musical notations are comparable to epigenetic marks– e.g., methyl or acetyl groups, among other moieties– that serve to modulate the expression of the underlying encoded/evolved genetic information. Placement of such marks is at the direction of the creator of the orchestral score. Before anyone loses their shite, by “creator” I mean the evolutionary processes that lead to the musical score, in toto, that we see, including the individual bits of sheet music that encode the DNA sequence-binding proteins whose activity prompts placement of those “epigenetic” marks.
@mithrandir
That looks good.
I think what trips some people up is the existence of inherited changes in gene expression/phenotype due to epigenetics, in addition to the developmental changes that are due to epigenetics within one’s lifetime. Inherited epigenetic programs will be preexisting things that could go in different direction depending on the experiences and exposures of ancestors, not something where one could try for different inherited things and expect whatever one wanted.
CRISPR?
epigenetics can put lipstick on a pig, but it can’t make a family of pigs with permanently red lips.