One prediction is that brain size should not be a constant,
it should grow larger & smaller between populations and
lifestyles.

Simple: Even a diet of the most DHA poor seafoods is
going to greatly exceed anything found on land. So the
results should be an enlargement of the brain.

How large?

Well... eh.

Meaning, it would be limited to genetics. Right?

It's not, "I ate some clams. I'm Einstein now. No moe
flinging poo for me!"

That's not what happened. Probably. It probably didn't
happen that way.

And maybe intelligence was something of an emergent
trait. Not so much selected for, just something that happened
because the brain grew bigger, and the brain grew bigger
because of all that seafood....

Or maybe they had to wait for some convenient genetic
mutation because they could start taking any real advantage
of their greater gray matter...

Doesn't matter. What is important here is that the lifestyle,
the environment -- the diet -- resulted in bigger brains. Change
that and you change the brain size.

Right?

So if you see something with a smaller brain size like.. like..
oh.. just making something up here.. like let's say that there's
this creature we call Sediba. And it's brain is too small. It kind
of almost looks Homo but it also looks like it's adapted more
towards something like a Chimp lifestyle (habitat) AND it has
a smaller brain.

Let's say our made-up animal, Sediba, is younger than some
finds labelled "Homo" but has a smaller brain. So doesn't that
tell us that it moved AWAY from an environment, a lifestyle, a
diet conducive to a larger brain, and towards one that only
supports a smaller one?

Hmm?

DISCLAIMER: I do *Not* like linear models. I hate the idea
that Some aquatic ape followed an freshwater outland inland,
at a root or scavenged an antelope then turned into a Chimp.

Nope. Double nope. Don't like it.

This is something -- a process, a "Dynamic" -- I see as happening
from the get go, and continuing even now.

Yes, as a matter of fact researchers do identify a loss of brain
size even in historic times! It seems to coincide with the rise of
empire, cities -- Civilization. Which makes sense: As grains and
the animals feeding on them (but mostly just the grains) grew as
a percentage of the diet, the DHA fell...

And this is why the fake science that is paleoanthropology is so
wrong with it's Selection/Preservation/Sample bias. Maybe Lucy
is an ancestor (I doubt it), maybe it's an inland group that has
already evolved away from the Aquatic Ape population. Maybe
it's the hybrid of the Aquatic Ape population and a group to have
previously peeled off and adapted to the inland environment...

Maybe, maybe, maybe. We don't know. But everyone assumes
that we do.

Evidence almost always supports more than one conclusion. What
you need to do is amass as much of it as you can until you reach
a point of convergence, where the evidence points to one
conclusion while excluding others. And that "Conclusion" has to be
a model that explains everything the best.

Yes, Aquatic Ape.

-- --

https://jtem.tumblr.com/post/708063715696820224

Hi JTEM,
-- Lucy is obviously IMO just a Pliocene relative of Gorilla, still aquarboreal (rather than aquatic):
frequently wading bipedally in forest swamps + climbing arms overhead in the branches above the swamp.
-- Au.sediba, OTOH, is an early-Pleistocene relative of Pan, hence less gorilla- & more human-like than Lucy was,
I'd think most related to Au.robustus?

______

Op donderdag 2 februari 2023 om 22:56:42 UTC+1 schreef JTEM is so reasonable:
> One prediction is that brain size should not be a constant,
> it should grow larger & smaller between populations and
> lifestyles.
>
> Simple: Even a diet of the most DHA poor seafoods is
> going to greatly exceed anything found on land. So the
> results should be an enlargement of the brain.
>
> How large?
>
> Well... eh.
>
> Meaning, it would be limited to genetics. Right?
>
> It's not, "I ate some clams. I'm Einstein now. No moe
> flinging poo for me!"
>
> That's not what happened. Probably. It probably didn't
> happen that way.
>
> And maybe intelligence was something of an emergent
> trait. Not so much selected for, just something that happened
> because the brain grew bigger, and the brain grew bigger
> because of all that seafood....
>
> Or maybe they had to wait for some convenient genetic
> mutation because they could start taking any real advantage
> of their greater gray matter...
>
> Doesn't matter. What is important here is that the lifestyle,
> the environment -- the diet -- resulted in bigger brains. Change
> that and you change the brain size.
>
> Right?
>
> So if you see something with a smaller brain size like.. like..
> oh.. just making something up here.. like let's say that there's
> this creature we call Sediba. And it's brain is too small. It kind
> of almost looks Homo but it also looks like it's adapted more
> towards something like a Chimp lifestyle (habitat) AND it has
> a smaller brain.
>
> Let's say our made-up animal, Sediba, is younger than some
> finds labelled "Homo" but has a smaller brain. So doesn't that
> tell us that it moved AWAY from an environment, a lifestyle, a
> diet conducive to a larger brain, and towards one that only
> supports a smaller one?
>
> Hmm?
>
> DISCLAIMER: I do *Not* like linear models. I hate the idea
> that Some aquatic ape followed an freshwater outland inland,
> at a root or scavenged an antelope then turned into a Chimp.
>
> Nope. Double nope. Don't like it.
>
> This is something -- a process, a "Dynamic" -- I see as happening
> from the get go, and continuing even now.
>
> Yes, as a matter of fact researchers do identify a loss of brain
> size even in historic times! It seems to coincide with the rise of
> empire, cities -- Civilization. Which makes sense: As grains and
> the animals feeding on them (but mostly just the grains) grew as
> a percentage of the diet, the DHA fell...
>
> And this is why the fake science that is paleoanthropology is so
> wrong with it's Selection/Preservation/Sample bias. Maybe Lucy
> is an ancestor (I doubt it), maybe it's an inland group that has
> already evolved away from the Aquatic Ape population. Maybe
> it's the hybrid of the Aquatic Ape population and a group to have
> previously peeled off and adapted to the inland environment...
>
> Maybe, maybe, maybe. We don't know. But everyone assumes
> that we do.
>
> Evidence almost always supports more than one conclusion. What
> you need to do is amass as much of it as you can until you reach
> a point of convergence, where the evidence points to one
> conclusion while excluding others. And that "Conclusion" has to be
> a model that explains everything the best.
>
> Yes, Aquatic Ape.