@T_aquaticus
I’m not ignoring anything. I am asking for specific examples of DNA differences that result in differences in embryonic development, and why you think those DNA differences can not be produced by evolution.
As I said in my previous response, we may not be in a position to do this yet. But even if we were and showed it was highly improbable to occur, you’d likely plead sharpshooter fallacy. But what we know already about gene regulation shows any constructive changes are extremely unlikely to arise opportunistically.
From extrapolations we estimate that 8.2% (7.1–9.2%) of the human genome is presently subject to negative selection and thus is likely to be functional, while only 2.2% has maintained constraint in both human and mouse since these species diverged.
So from this you infer that approx. 90% of the genome is evolving at a rate consistent with neutral mutations. However, how did they derive their estimate? By comparing genomic sequences of different mammals. Most of their 10% is focused on protein-coding sequences, so it is not surprising that there is relatively little changes in sequence, even between different species. However, they then assume that the differences between mammals in non-coding sequences implies that these sequences are subject to ‘turnover’, which you imply (I don’t think the authors actually say so) means susceptible to neutral mutation. But this extrapolation is based on assuming that eg humans and mice have diverged from a common ancestor. And, the question to ask is: much of the non-coding sequences are repeats; wouldn’t repeats have been randomised by neutral mutations? (Another indication that their rationale is unsound is that, because they conclude these non-coding sequences are mutable, they conclude that a large proportion of this could be deleted without impacting on fitness (p8). Whereas we know that much of non-coding regions are required for eg packing of DNA.) So, I’m going to look into this further, but I think these differences between the non-coding regions of different mammalian (and other vertebrate?) groups may provide further genomic evidence against common ancestry. So thank you for drawing it to my attention!
@T_aquaticus
They say explicitly that neutral mutations only evolve neutrally in 5% of the genome. It isn’t saying that neutral mutations can only occur in 5% of the human genome. Neutral mutations and evolving neutrally are two different things.
It explicitly states that neutral mutations can evolve non-neutrally.
Agreed. But even taking this into account (and the paper discusses various examples) she still concludes that only about 5% of the human genome is susceptible to neutral evolution, as my previous quote, and this is from the subtitle of her paper
Just 5% of the human genome is subject to neutral evolution,
So it’s hard to maintain as you do that she doesn’t mean it.
@T_aquaticus
Why would it have to be two specific bases? Do you think there is only one such interaction possible in the human genome? If so, I would love to see that evidence.
For example, how many combinations of two mutations in the modern human genome can result in a beneficial phenotype? Don’t you have to know this number before you can calculate probabilities of one such interaction being found?
Based on what we know about the length of control sequences for genes, which I mentioned last post, how many two-specific bases do you think will lead to a beneficial phenotype, and why?
@T_aquaticus
The problem is your calculated probability. You are also ignoring the parallel nature of sexual reproduction which can combine beneficial mutations from separate genetic backgrounds into the same genetic background. For example, let’s say there are 100 possible beneficial mutations that are not linked (i.e. are far enough apart in the genome to allow recombination). The odds of getting these 100 mutations is not 100 times the probability of getting 1 of them. Rather, these 100 mutations will occur in different individuals within the population. As these beneficial mutations increase in frequency you will start to get an accumulation of beneficial mutations due to sexual reproduction. This greatly increases rate at which evolution occurs.
What you then need to take into account is the probability of those specific 100 coming together within a population of a given size (and without others that might counter the effect of some of them).
@T_aquaticus
If none of these coordinated mutations for development can even be cited, then what’s the point?
Taking account of what we do know, rather than relying on what we don’t (evolution of the gaps).
@T_aquaticus
I know what it means.
If you know what fixation means then you’ll agree that ‘fixed’ mutations are susceptible to change. And if so, then why do you keep repeating that fixation will happen. That’s not in question.