
Unified Theory of Evolution - yawz
https://aeon.co/essays/on-epigenetics-we-need-both-darwin-s-and-lamarck-s-theories
======
Obi_Juan_Kenobi
This is nonsense.

Epigenetics did nothing to contradict Darwinian evolution, so no 'revision' is
necessary. The references to Lamarck are utterly bizarre; giraffes are not
lengthening their necks via epigentics, and the 'will' of organisms remains
irrelevant to evolution. It is descriptive only insofar as it's somehow
'outside' Darwinian evolution, but that is not true.

Epigenetics did a few things:

* It showed that some multi-generational effects can be made from environmental influence. This is very interesting, with many fascinating effects, but this ultimately is controlled by the primary nucleotide sequence. Epigenetic regulation cannot occur without the proper target sequences, and no epigenetic modification can be maintained indefinitely.

* It can do some 'tricks' (e.g. paramutation) that _actually_ confound Mendelian inheritance, thus requiring revision in that sense.

* It showed that gene regulation, viral defense, and defense from self-replicating genetic elements are all related in a wonderfully fascinating way.

None of this overturns Darwinian ideas; they fit squarely on top of them. It
is a further elaboration of the primary genetic sequence in much the same way
that protein translation is. Evolutionary novelty still comes from changes to
nucleotide sequence, and those sequences prosper according to chance and
natural selection.

~~~
somestag
In my reading of the article, I never detected a suggestion that Darwinian
evolution was flawed or incorrect. In fact, as far as I can tell, the article
says exactly what you're saying: that a complete understanding of evolution
involves understanding that both evolutionary and epigenetic forces are at
play. In other words, the _template_ changes, but so does the _expression_ of
that template. In fact, the summary paragraph in the article says we need to
_add_ epigenetics to Darwinian evolution, just as you say these newer ideas
"fit squarely on top" of Darwin's.

------
mudil
I am reading (for a review) upcoming book by Denis Noble called "Dance to the
Tune of Life: Biological Relativity" (Cambridge Univ Press). In the book he
lays out many important problems with neo-Darwinism, and neo-Lamarckism
showing up in unexpected places. The big idea of the book is what we are
seeing now with biology is what happened to physics when
geocentric/antropocentric view of the world collapsed with Copernicus-Galileo-
Newton-Einstein, and there was no center any more. Basically while Dawkins and
other "high priests of neo-Darwinism" believe in centrality of genes
(replicators), the new paradigm that is emerging is that there is nothing
central to genes. "The genome is an organ of the cell," as Barbara McClintock
said. DNA is just a dead molecule. There is so much more to evolution to
consider than just building organisms around replicators, because there are so
many different scales we need to consider: subatomic-atoms-molecules-polymers-
organelles-cells-tissues-etc etc.

And since it's hacking forum, the book discusses the other problem with DNA
being the only book of life: it's an incomplete program to be responsible for
creating a fully functional output, because it is linear without true logic
elements.

------
lvs
Wow, OK. This article is awful and shouldn't be propagated. First of all,
nobody serious is promoting any Lamarckian theory of evolution. The claim that
mutation rates are too slow to explain phenotypes is completely bizarre.
Nothing about modern measurements of mutation rate undercut Darwinianism or
promote Lamarck. This is utter nonsense.

If the framing was intended to present a molecular mechanism for inheritance
via epigentics that is distict from classical genetics, then nothing about
Lamarckianism is relevant whatsoever. We simply have expanded our
understanding of genetics and short-term heritability to include epigenetic
modifications, but modern genetics is not somehow in conflict with Darwin.
Epigenetic changes occur during development and may be affected by
externalities within an individual in a manner that biases the propagation of
genotypes. But epigenetics is in no way teleological in the manner that
Lamarck proposed.

------
FullMtlAlcoholc
Interesting. I wonder if the Environmental changes caused by climate change
would accelerate epigenetic change. Also would it matter in a post-crispr
era.?

