Started skipping through the hangout to see if there’s anything interesting.
Very first claim I hear at 16:16-16:32 is that apparently there’s no way that 30 million DNA could be fixed between humans and chimps since they diverged several million years ago. This is trivially untrue. The calculations are just so easy to do, even on the back of an envelope. Say we diverged 6 million years ago, and have a generation time of 20 years. That’s 6,000,000/20*2 = 600,000 generations (total from both lineages. At a (haploid) mutation rate of around 50 mutations per generation, that’s 30 million mutations. The vast majority of these are neutral, and neutral mutation fixate at approximately the mutation rate, so on those rough numbers we can easily account for 30 million DNA differences. SFT can’t even get the very basics right.
Edited because I forgot to make the mutation rate haploid, silly me (see @glipsnort’s correction below):
I’m most surprised by Rob Carter on his podcast. Carter is a real scientist and is far more coherent than @SFT. I don’t know why Carter would link himself to a spokesman that is just going to bring him down.
SFT demonstrates once again that he doesn’t understand the TMR4A method. I think he’s under the impression that the analysis is done until there are 4 alleles total in the entire collective genome of the population (the 2 people), this is why he thinks the “real model” should have Adam and Eve’s genomes containing “millions of lineages”. He doesn’t understand that the TMR4A is performed on many small chunks of the genome, and that each TMR4A time is specific to a specific genomic sequence, and the time of 500,000 years is based on the median of all these dated sequences.
Oh boy I didn’t know he had made a video on the foremen magnum.
I just watched it as well and left this:
"Agh guys. Eyeballing the foremen magnum is not how an organism is deemed bipedal.
For those curious, here are a series of papers detailing the dozens of measurements that go into assessing the foremen magnum (position and angle) and other basicranial features with regard to predictive power (ah yes, the gold standard of science):
Locomotion, posture, and the foramen magnum in primates: Reliability of indices and insights into hominin bipedalism
(2020)
Another look at the foramen magnum in bipedal mammals (2017)
Locomotor pattern fails to predict foramen magnum angle in rodents, strepsirrhine primates, and marsupials
Foramen magnum position in bipedal mammals
(2013)
Please appreciate that basicranial features, along with FMA and FMP can distinguish quite easily between obligate/facultative bipeds and quadrupeds. I suggest taking a serious tour of vertebrate anatomy and paleontology terminology and methods."
Now he’s going on about recombination rates, relying entirely on the interview clip with Carter. I’ve already covered those claims in this thread the other day:
He also keeps saying that we think recombination is random because we’re behind the times. I’ve no idea where’s getting that idea from. Speaking for myself, I’ve known about the influence of PRDM9 for years. SFT is more likely the one that’s only just picked up this tidbit from Carter, so now he’s projecting his ignorance onto us.
There’s nothing much else to the video. Roughly 24:00-60:00 are the main section addressing comments here on PS about TMR4A if anyone wants to narrow down their watch time. As usual, 90% posturing about how ignorant we are and how we were falling all over ourselves trying to defeat his arguments in the thread where he briefed joined in the conversation. The points could have easily been distilled into a <10 minute video, but he just can’t help himself.
Given that the divergence between orangutans and gorillas is far greater than the divergence between humans and chimpanzees, this would be a rod for their own back. If they want that to be the hill they die on, at least the war will be short.
Ha! I was there when Simon Myers identified the motif that PRDM9 binds to and figured out it was probably a zinc finger protein – we shared an office at the time. And before that, in 2002, I and my co-authors wrote, “The results are best explained by extreme variability in the recombination rate at a fine scale, and provide the first empirical evidence that such recombination ‘hot spots’ are a general feature of the human genome and have a principal role in shaping genetic variation in the human population.”
Thanks for the correction! I had a feeling something was off because when I’ve pointed this calculation out before it always came to around 30 million. That’s what I get for writing comments at 1am.
