First, it is important to differentiate between evolution and adaptation since not all evolutionary changes are adaptive.
Genetic drift contributes genetic variation that can interact with future mutations or future changes in the environment. Epistasis is an important concept, and one of the drivers of epistasis is neutral mutations.
It took the first two chapters of my book to discuss the controversy, compare the evidence for and against ns as the main mechanism of evolution, and draw my conclusion.
Of course, it can cause the founding of a new species
Oddly enough, thereās good evidence that most speciation is due to selection.
What exactly do you mean by āmain mechanism of evolutionā? How is it determined whether a mechanism is the main one? What do you quantify to determine that?
Iām skeptical. My question was whether you read the primary literatureāthe stuff with the evidence, which is less about reading and more about examining the actual evidence presented.
So far, everything youāve written here is evidence-free name-checking.
Which makes evidence even more important than rhetoric.
Science is more complicated than Popper in the real world.
I do know that your name-checking comes across as a parody of academic writing. Have you considered discussing ideas without even mentioning names? It might be more fruitful.
Itās not intact. Neutral theory, of which you were apparently ignorant until yesterday, is a huge modification to it.
Theories are corroborated by making successful predictions, not their explanatory power. Behavioral evolutionary biology is not nearly as impressive as you claim it to be.
And the possessive pronoun is āits,ā not the contraction āitās.ā āItāsā means āit is.ā
Both, actually. You use both to select among useful and successful models.
Impressiveness is entirely in the eye of the beholder of course. Regardless, natural selection really does have enormous explanatory(and predictive) power in animal behavior, and people generally have no problem with that until the topic turns to humans, and then everyone loses their minds. Itās ridiculous.
The default explanation for adaptive behavior is adaptation, that is natural selection. Not to be confused with the default explanation for any and all behaviors, or any and all attributes. That means the first hurdle to be overcome when considering an explanation for a behavior is to elucidate whether it is adaptive or not compared to the presumed ancestral state, or itās absence. If it is, thereās absolutely nothing wrong with concluding the behavior owes to natural selection.
Itās all in my book. And no matter what you say, the scientific consensus still is that natural selection is the main mechanism of evolution. I am not a scientist, but as a scholar know how important the scholarly consensus is. And so many award winning geniuses are Darwinian evolutionists.
The predictive power of Darwinism amazing
Yes, I have mentioned the predictive as well as explanatory power of natural selection.
There is no clear consensus that natural selection does more than neutral evolution because the evidence remains inconclusive.
You appear to be unaware that there is no consensus as to whether selection or drift dominates. What happened to the evidence?
And how many award-winning geniuses conclude that neutral dominates? Really, thereās no one who thinks that it doesnāt play a significant role.
Youāre still placing opinion above evidence.
Natural selection has made many successful predictions. So has neutral theory.
Sure. But genes make it through to subsequent generations only as part of whole phenotypes. What Iām struggling with is, not that drift happens, what does drift result in that is not random. Prof Felsenstein talks of drift as an unavoidable aspect of evolution as Brownian motion is to gas molecules. The effect of Brownian motion is universal, random.
I could say the opposite and my statement would be as correct. Selection drives adaptation. John Harshman says selection is involved in speciation. I get the idea that drift may result in novel alleles fixing randomly and this effect is stronger in bottlenecks. So itās both. Perhaps a few examples of evolution where selection can be ruled out would help.
Among other things, modern humans have been around for only about 200,000 years, or about 10,000 generations.
Is that sufficient time for behaviours adaptive to particular conditions to evolve genetically, especially when conditions have changed so incredibly dramatically in that time? (e.g. the last ice age ended only 12,000 years or about 600 generations ago).
How about most of your genome? Only 10% is under selection, and most of that is purifying selection that gets rid of new mutations. Of the 40 million mutations separating you from a chimp, only a few thousand, at most, result from selection. In terms of sheer volume, drift is the dominant force in evolution.
Yes, that was my point.
Yes, that was my point. The consensus is that there is no consensus.
Of course thereās a consensus! And Mendelian genetics explains drift
The consensus is not reductive to natural selection.
Over evolutionary time genes go their separate ways by mutation, selection and drift. Yes evolution has to be understood in a nuanced way. But human behaviour is universal and overall fits the big picture of natural selection imo.Any surprising, inexplicable divergences in my opinion (the exception proves the rule!) have an underlying religious/spiritual explanation, because (I know this is subjective opinion) we are not purely natural creatures.
Dawkins says that contrary to what people think he has always had a lot of time for the neutral theory of the great Japanese geneticist Motoo Kimura. He loves the molecular clock idea. But goes on to argue that āthe neutral theory does not in any way denigrate the importance of selection in nature. Natural selection is all powerful with respect to those visible changes that affect survival and reproductionā. Neutral means neutral! Darwin himself anticipated the neutral theory in The Origin of Species when he wrote āThis preservation of favourable variations and the rejection of injurious variations, I call natural selection. Variations neither useful nor injurious would not be affected by natural selectionā.
Genes donāt. Alleles do. You clearly are not grasping the most basic concepts.
We have plenty of expertise ourselves. What exactly is the point of your lecturing us about what people say?
You still havenāt answered my question: do you read the primary scientific literature?
That is a quote from Dawkins. Of course I know what alleles are. Itās only molecular geneticists who strictly use the word allele for alternative versions of a gene. My kids either got my or my husbandās allele for blue eyes, not my husbandās brown one, cos he has brown eyes. But when Iām chatting about it I use the word gene. You guys with scientistic mindsets have the most reductive minds, no appreciation of writing style, or any form of speculation no matter how informed. No point discussing my opinions with you no matter how evidenced based. And I am not lecturing you. I am a theologian trying to integrate science and faith, interpreting evolutionary science from a faith perspective. And yes I have read plenty of primary scientific literature. And have cited it where necessary in my book. No interest in discussing it with those of a scientistic mindset. Scientism a big problem in the modern era, another issue discussed in my book.
I think you will find that itās any biologist who talks about alternative versions of a gene, though one might be a bit looser when writing for a public that doesnāt know the word.
One issue in contention here is whether your speculations are informed. The biologists who respond to you think not. This is a problem considering that your speculations are about the opinions of biologists.
My speculations are based on the work of the leading evolutionary biologists and scientists who assert that human nature has been shaped by natural selection. I have of course read the work of those like Gould who disagree, and got an excellent endorsement from Michael Ruse a multi award winning philosopher of science who specialises in the philosophy of biology and is also as scientifically knowledgeable as any evolutionary scientist, and recognised as such by leading ones such as E.O. Wilson.He is an expert on the intra-scientific controversy on the issue, has written extensively about it and as I have said won loads of awards, including the Guggenheim Fellowship for Natural Sciences. He also has written prolifically on the religion/science controversies. His conclusion is that human nature has indeed been shaped by natural selection, that Dawkins and those who share his opinions are correct, and Gouldians wrong. He is also an atheist, but an expert on the creation/evolution debate. You biologists who disagree that human behaviour has been shaped by natural selection are just one side of the controversy. Those with scientistic mindsets canāt see the wood for the trees! And not all of those who have responded to me disagree.