rba
You’re right re the Khoisan, and I raise this exact point at the very end of the substack series I did. This section ended up cut from the LW version.
https://goflaw.substack.com/p/on-the-evolutionary-origins-of-human-d8c?r=41a8s8
Re the sexual selection story, like you, I don’t see any reason the story couldn’t apply pre-Neanderthal split, but my read of the existing papers exploring this subject was that the authors viewed it as a modern trait, which was what I went off of here.
Incoming followup post entitled “Who lost their baculum first and how we lost it”.
Any followup would be on substack probably, not here.
What’s the Wurtz reference?
Geoffrey Miller pretty persuasively argued in his book the penis issue is a mate choice issue.
And nah these are different things. I think there’s an academic bias to lump all the sexy stuff together because we love talking about Unified Theories of Sex.
I think gorillas do as well. These ideas have never made sense to me.
I’d argue the more interesting and potentially related human trait isn’t cycle-independent sexual receptivity, but hidden estrous, which is even more uniquely human.
For either trait, I don’t know how you would assemble a gene panel for study. You can’t use GWAS results because all of these traits are fixed in modern humans. The only reason the involution panel supports this type of analysis is because of extensive and unrelated experimentation in mice.
I think Sarah Hrdy is the person who’s most carefully examined this line of reasoning.
I think a lot of the European/(East?) Asian difference you’re referring to is because of polymorphism in the EDAR gene.
It’s the OnlyFansification of everything.
This is a very interesting post.
I’d lean toward the latter, but I just don’t think we know.
Or you’d be persuaded if they switched “a” to “i” back to “a” in biologically implausible time?
This is handwaving. To make such a claim, you need reference to the mechanism or at least the anatomy. As a source, sperm whales don’t have a larynx, but they have phonic lips. As a filter, they don’t have tongues or lips or throats in the way we do, but they have a distal air sac. Is that what they’re “changing the length” of ? Is that what they’re “changing the tension” of?
“I think for your speed argument to be relevant, you need to show that the whales are switching between sounds at a biologically implausible speed”. Yes, this is exactly right. Look at Fig 6 above.
The spectral pattern switches from “a” clicks to “i” clicks in at most 100 ms (there might be 30 ms between clicks and each of those click samples is 5 ms). That’s really fast. It rivals the human motor system governing our articulation. It’s ambitious to claim whales have such capabilities without detailed anatomical references that the authors don’t make.
As I noted elsewhere in these comments, the intracoda timescale is borderline as well, and would rival human abilities. A huge claim.
I hadn’t considered the overtone issue. I need to think about that…
The intraclick and intracoda “adjustment by muscles” is precisely what I’m disputing.
There are several possibilities that I hope sharpen this up.
The whales have motor articulatory control at the intraclick level, which is why you see the different spectral “vowels” in a single click. Since you see this in 5 ms intraclick samples, they must have control on those timescales or smaller. As the bird people I cite above state, this seems completely implausible, possibly by several orders of magnitude in time. For what’s it’s worth, my correspondence with the authors on pubpeer makes it clear they’re not claiming this.
The whales have motor articulatory control at the intracoda level, which is why you see the mixed coda types (Fig 6.). However, the spectral change you see in these example occurs within at most the 100 ms range (like you said, say maybe 10 ms per click plus 30 ms in between) which is about human-level abilities. Unlike 1, this isn’t completely implausible, but it seems like a very ambitious claim.
The whales don’t have motor articulatory control at the intracoda level, and the mixed codas actually represent a beaming artifact/interference pattern of the kind outlined in the post. However, once you concede that, it becomes parsimonious to say that actually “i” vowels are themselves a beaming artifact. This also explain the intraclick pattern as well.
It’s a little unclear, but I think the authors are claiming 2 is correct. I think they’d need to concede intracoda articulatory control to get this to work (or at least to explain the large minority of mixed-type codas). I’m claiming 3 is correct.
The mixed codas seem like strong evidence against this view, or at least strong evidence against the claim that the “a”/”i” are an example of what you’re describing.
This is a great point with regards to how plausible the various scientific animals communications claims actually are, but to my eye, the CETI people look motivated in the same way as the Koko people or your local crazy cat lady.
Yes, the Eriksson study was one of ones supporting an early draft of this analysis. I didn’t end up using it because it didn’t make much sense to do so. Size isn’t the issue here; permanence is.
Erikkson only looks at Europeans, so I don’t know about the cross-population comparison here.
EDAR polymorphism does work through plausible pathways to produce the size difference and has other drastic phenotypic effects, but yeah nothing’s proven.