A solid effort at thinking from first principles and hew close to indisputable facts.
And yet...the natural-selection framework is very unwieldy (I'm not arguing for any other) because it is starkly anti-teleological ("there was no plan, this only *happened*"), whereas we are hard-wired (it would seem) to think teleologically ("this happened for that *purpose*). Accordingly, it is very difficult (and scientists fall into this trap all the time) to describe things in a language that is intelligible but "true" to the natural-selection "logic". This accounts in large part for problems #1 and #2 that you mention, in particular the "just-so-story" problem.
Here's an example: "Both these adaptations—along with skin with hair rather than fur *designed* to release and manage heat via sweat—are clearly selections for a tool-using species [...]" (my emphasis). It may, or may not be true that fur-less skin is better at shedding heat - it *does* sound intuitively plausible of course, but where's the testing of that simple property? Never mind that a fur-less animal is better at running in mid-day heat than a furry one, *all other things being equal*? But the giveaway is the inadvertent use of "designed", because it comes so naturally, doesn't it? And that's precisely the problem. As a species, we're primed to see "designs" everywhere and if we fought this tendency all the time to remain true to the framework, we'd bore ourselves silly and would never get anywhere (or maybe it would read like Marxist prose, ahaha). But going with the flow keeps yielding these slightly suspect, just-so stories, alas.
Awesome! I was surprised you didn’t have a point about fire use. The control of fire as a technology both required cognitive abilities (ability to plan and think many steps ahead), and affected the path ahead (meat, ability to handle cold climates, loss of fur, smaller digestion, need to coordinate around cooking and delayed gratification, etc).
People require mates and resources to propagate. Lineages disappear. They bend back on themselves. They compete for whatever limited number of niches exist. Competition for niches is a fundamental driver of natural selection because niches are limited in number.
Yes, we humans create niches in a way no other species does, but niches are not created merely by having children. Malthusian dynamics have had a huge effect on human social dynamics precisely because constraints on the number of niches are real.
Population growth requires expansion in the number of niches. Our level of technology, particularly of control and use of energy, has much to do with that.
“All divergences on this tree before 7 kya were binary, suggesting that during the Paleolithic Age, slow population growth and bottlenecks or drift eradicated most of the ever existing clades.”
So divergences after 7 kya were not binary, is that what you and the Chinese authors there are saying? Or are they just trying to dress up their paper in unnecessary opaqueness?
BTW one person's ancestors at 2^y (binary aye) 7kya are too many for the planet.
English is not their first language. What they are saying is after that, you get much bigger divergences in reproductive success between lineages.
The limit to population is not the capacity to have children, it is the capacity to support them. (Hello, Rev. Malthus.) Hence, simple multiplying calculations of possible descendants are irrelevant, even without considering that people with shared ancestry (if you go far enough back) marry, even in societies with expansive incest taboos.
I'm going backwards not forwards, ancestors not descendants. And there is a genuine issue for ancestry math and it happens pretty damned quickly. 2^300 (say 7000 years) is a number that my calculator is not too keen on (2,037,035,976,334,487,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000)
One person's ancestors 7000 years ago. Vastly more than 8 billion people. Even allowing for occasional cousin or sister/brother mating it is far (far, far, far) too large to be explained. More ancestors in fact than atoms in the universe.
What part of the limit to population is the number of niches/carrying capacity did you not understand? It is true whether you go forward or backwards.
Lineages interweave. It is not a matter of “cousin” marriage. We are not talking Carlos the Cursed, where 9 of the 16 slots for female ancestors that far back were occupied by Joanna the Mad. It is true, however, that individuals occupy more than one “slot” in the notional ancestry tree. The further you go back, the more that is true.
The trouble is Lorenzo that it is not enough. I can go back in my family tree to 1700 and there ain't one ancestor in that tree that occupies more than one spot. That is 325 years, or 8192 ancestors at 25 years a generation (generous I figure). If I do that for everyone on the planet then you have a 65,536,000,000,000 (65,536 billion) population at 1700 or so.
Only one person so far has engaged with the numbers on this issue. And their view is the same as mine. Cousin matings do not go close to explaining it nor does ignoring it and posting about some other issue from an evolutionary viewpoint.
In fact the numbers issue really fucks with evolution I have to say.
A solid effort at thinking from first principles and hew close to indisputable facts.
And yet...the natural-selection framework is very unwieldy (I'm not arguing for any other) because it is starkly anti-teleological ("there was no plan, this only *happened*"), whereas we are hard-wired (it would seem) to think teleologically ("this happened for that *purpose*). Accordingly, it is very difficult (and scientists fall into this trap all the time) to describe things in a language that is intelligible but "true" to the natural-selection "logic". This accounts in large part for problems #1 and #2 that you mention, in particular the "just-so-story" problem.
Here's an example: "Both these adaptations—along with skin with hair rather than fur *designed* to release and manage heat via sweat—are clearly selections for a tool-using species [...]" (my emphasis). It may, or may not be true that fur-less skin is better at shedding heat - it *does* sound intuitively plausible of course, but where's the testing of that simple property? Never mind that a fur-less animal is better at running in mid-day heat than a furry one, *all other things being equal*? But the giveaway is the inadvertent use of "designed", because it comes so naturally, doesn't it? And that's precisely the problem. As a species, we're primed to see "designs" everywhere and if we fought this tendency all the time to remain true to the framework, we'd bore ourselves silly and would never get anywhere (or maybe it would read like Marxist prose, ahaha). But going with the flow keeps yielding these slightly suspect, just-so stories, alas.
Yes, I should have said ‘structured’. But we are very much oriented towards intention/purpose. See, for example, Aristotle’s theory of causation.
Awesome! I was surprised you didn’t have a point about fire use. The control of fire as a technology both required cognitive abilities (ability to plan and think many steps ahead), and affected the path ahead (meat, ability to handle cold climates, loss of fur, smaller digestion, need to coordinate around cooking and delayed gratification, etc).
Excellent point. I really should have said something about fire. I will add fire into the next post in the series.
Interesting start
Yep very interesting Lorenzo. But can you explain this?
https://plebeianresistance.substack.com/p/the-models-of-earth-that-we-have
People require mates and resources to propagate. Lineages disappear. They bend back on themselves. They compete for whatever limited number of niches exist. Competition for niches is a fundamental driver of natural selection because niches are limited in number.
Yes, we humans create niches in a way no other species does, but niches are not created merely by having children. Malthusian dynamics have had a huge effect on human social dynamics precisely because constraints on the number of niches are real.
Population growth requires expansion in the number of niches. Our level of technology, particularly of control and use of energy, has much to do with that.
“All divergences on this tree before 7 kya were binary, suggesting that during the Paleolithic Age, slow population growth and bottlenecks or drift eradicated most of the ever existing clades.”
https://pmc.ncbi.nlm.nih.gov/articles/PMC4149484/
So divergences after 7 kya were not binary, is that what you and the Chinese authors there are saying? Or are they just trying to dress up their paper in unnecessary opaqueness?
BTW one person's ancestors at 2^y (binary aye) 7kya are too many for the planet.
English is not their first language. What they are saying is after that, you get much bigger divergences in reproductive success between lineages.
The limit to population is not the capacity to have children, it is the capacity to support them. (Hello, Rev. Malthus.) Hence, simple multiplying calculations of possible descendants are irrelevant, even without considering that people with shared ancestry (if you go far enough back) marry, even in societies with expansive incest taboos.
I'm going backwards not forwards, ancestors not descendants. And there is a genuine issue for ancestry math and it happens pretty damned quickly. 2^300 (say 7000 years) is a number that my calculator is not too keen on (2,037,035,976,334,487,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000)
One person's ancestors 7000 years ago. Vastly more than 8 billion people. Even allowing for occasional cousin or sister/brother mating it is far (far, far, far) too large to be explained. More ancestors in fact than atoms in the universe.
Makes zero sense.
What part of the limit to population is the number of niches/carrying capacity did you not understand? It is true whether you go forward or backwards.
Lineages interweave. It is not a matter of “cousin” marriage. We are not talking Carlos the Cursed, where 9 of the 16 slots for female ancestors that far back were occupied by Joanna the Mad. It is true, however, that individuals occupy more than one “slot” in the notional ancestry tree. The further you go back, the more that is true.
The trouble is Lorenzo that it is not enough. I can go back in my family tree to 1700 and there ain't one ancestor in that tree that occupies more than one spot. That is 325 years, or 8192 ancestors at 25 years a generation (generous I figure). If I do that for everyone on the planet then you have a 65,536,000,000,000 (65,536 billion) population at 1700 or so.
It does not work.
Either the maths is wrong or our Earth is wrong.
Only one person so far has engaged with the numbers on this issue. And their view is the same as mine. Cousin matings do not go close to explaining it nor does ignoring it and posting about some other issue from an evolutionary viewpoint.
In fact the numbers issue really fucks with evolution I have to say.
The statistic is completely wrong about the number of ancestors in that post. But, I will leave it to you to figure out why.
I see, in other words you cannot explain it either.
Mr 3 subscribers one of whom is Lorenzo and one of whom does not show up.
Also my comment here.
https://substack.com/profile/32104763-richard-seager/note/c-285954896