This is oddly poignant to me. I just (literally a few hours ago) submitted my PhD thesis on (broadly) the biophysics of emergent phenomena. People don't usually read theses cover to cover, with good reason, but I included one short paragraph in the preface to be the true "take home" message:<p><i>We wish to understand mechanism through the elucidation of design principles, yet evolution does not select for principles, it selects for fitness, an epistatic and emergent property. If similar outcomes can be achieved in different but equivalently fit ways, then given the stochastic nature of evolution this is almost guaranteed to happen. We have specific examples where every statement in the preceding paragraph is true [ed: a collection of proposed mechanisms]. We do not need one person to be right or wrong; our nascent understanding of complex biological systems is that the space of information-processing solutions is astronomical. Think of the diversity observed in structural biology - the repertoire of tertiary structures is enormous. There are countless examples of nearly identical functions being performed by proteins with radically different structure.<p>This divergence, this variety in structure and function, is what makes evolution robust. It is an inherent bet-hedging mechanism woven into the fabric of statistical physics. On the contrary, the desire to categories and abstract complexity into distinct groups is an inherently human endeavour. Much as we may wish and as convenient as it would be, Nature does not have a plan.</i>
This is pretty straightforward. The existance of the epigenetic mechanism is, itself, a result of Darwinian evolution.<p>Where epigenetics seems weird to people is simply that it goes beyond the modern synthesis -- i.e. it's not just DNA base pairs. But plain-ol' Darwinian evolution doesn't depend on genetics via DNA base-pairs, it depends simply on inherited characteristics, however they are inherited.
I'm not a biologist. Can someone that knows more here help me out?<p>From the article it seems epigenetic mechanisms aren't inheritable i.e. they do not change the DNA just how the DNA is interpreted and/or which genes are activated. So even though epigenetic mechanisms might get passed on for several generations once the environmental factor affecting the mechanisms is removed the organisms would revert wouldn't they?<p>It seems all this does is allow some Lamarckian traits to act as a factors in the natural selection process.<p>Also the two explanations for how Giraffes got their long necks seem pretty ridiculous to me. Does anyone know of legit research into that topic?
Gregory Bateson has a good piece in one of his books (it might have been "Steps to an Ecology of Mind") where he derives from cybernetic principals the result that Darwinian evolution <i>works better</i> than Lamarckian.<p>The key insight is that we can think of meta-evolution driving the form of the "first-order" evolution, meaning we evolved to evolve Darwinian-ly. (In practice meta-evolution cannot be separated from evolution, there is only one.)<p>This implies that we should <i>expect</i> limited Lamarckian evolution anywhere it leads to greater fitness than Darwinian.<p>From this POV epigenetic mechanisms are expected.<p>(I still look askance and the so-called "Central Dogma" of biology. Why on Earth would you assume that genes can't be changed by soma? If there was adaptive advantage to being able to edit DNA then it seems like cells and viruses would have it.
As I typed that my brain said: CRISPR stoopid. SO, yeah, duh.)
Since biologists and evolutionists are liken to gather here, I would like to ask something that's been occurring to me lately: does evolution explain all the things? For example, does it explain my personal musical taste? Or perhaps the aesthetic tastes of those birds that mate based on aesthetic choices? If evolution doesn't explain these and other factors that are involved in natural selection, so we can say that external factors (explained by what?) are involved in the process of evolution, so evolution may be being partially caused by other, non-emergent, forces?<p>I don't know if this is clear or if it makes sense. Please feel free to say I'm stupid.
I often thinks 'Evolution' is a shifting goal post.<p>They just keep redefining it to suit new information.<p>Given by mass the majority of mammals (ok pretty specific) have been designed. I'm not sure it's currently true.
The nature is not set on supporting our positivist "yes or no" theories.<p>Which means, for every theory that says "A is causes by X and not by Y", there will be a few cases where the inverse is true.<p>The solution is probably to stop making a religion out of knowing a few true yes/no theories, and understand the why's.