To my mind, we need an event.

We need something precipitating the split, causing
divergence.

The ice age, the glacial/interglacial cycle which aligns
just about perfectly with the Homo line is exactly the
kind of thing I'd want to see. Sea levels dropped as the
glaciers group -- by hundreds of feet -- and our ancestors
spread far & wide. But then the glaciers melted, sea level
rose and they were cut off from each other...

The glacial/interglacial cycle is the real climate change. It
turned places like the Sahara Desert, the Levant & Saudi
Arabia verdant, and then made them deserts... forcing
migrations... forcing adaptations...

This is the engine of human evolution!

But if this is what precipitated divergence, it's what pushed
Pan & Homo apart then it happened less than 3 million years
ago. Probably less than 2.5 million years ago.

Hmm.

If you want to push things back further then you need another
mechanism.

Mutations?

There was the chromosome fusion that humans underwent.

Could that be it?

But you need something.

And, that something dates it all.

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https://jtem.tumblr.com/post/655997404950249472

Op woensdag 7 juli 2021 om 09:01:18 UTC+2 schreef I Envy JTEM:

> To my mind, we need an event.
> We need something precipitating the split, causing
> divergence.

Simple geography:

Miocene hominoids lived in coastal forests of Tethys & para-Tethys seas:
vertical waders-climbers,
google "aquarboreal",
then
-hominid/pongid split = Mesopotamian Seaway closure, c 15 Ma
-hominids along Red Sea:
--Rift after c 8 Ma: Gorilla-Praeanthropus afarensis-aethiopicus-boisei...
--Homo/Pan split c 5 Ma:
--E.Afr.: Pan-Australopithecus africanus-sediba-robustus...
--S.Asia: archaic Homo: erectus...

Google
"ape human evolution made easy PPT verhaegen"
"coastal dispersal Pleistocene Homo PPT"

_____

> The ice age, the glacial/interglacial cycle which aligns
> just about perfectly with the Homo line is exactly the
> kind of thing I'd want to see. Sea levels dropped as the
> glaciers group -- by hundreds of feet -- and our ancestors
> spread far & wide. But then the glaciers melted, sea level
> rose and they were cut off from each other...
>
> The glacial/interglacial cycle is the real climate change. It
> turned places like the Sahara Desert, the Levant & Saudi
> Arabia verdant, and then made them deserts... forcing
> migrations... forcing adaptations...
>
> This is the engine of human evolution!
>
> But if this is what precipitated divergence, it's what pushed
> Pan & Homo apart then it happened less than 3 million years
> ago. Probably less than 2.5 million years ago.
>
> Hmm.
>
> If you want to push things back further then you need another
> mechanism.
>
> Mutations?
>
> There was the chromosome fusion that humans underwent.
>
> Could that be it?
>
> But you need something.
>
> And, that something dates it all.

On Wednesday 7 July 2021 at 08:01:18 UTC+1, I Envy JTEM wrote:

> We need something precipitating the split, causing
> divergence.

Splitting events are common and usually trivial.
The Congo River apparently changed course
~2 ma, splitting chimps into pan.troglodytes and
the bonobo.

> The ice age, the glacial/interglacial cycle which aligns
> just about perfectly with the Homo line is exactly the
> kind of thing I'd want to see.

Firstly, there was no need for anything as drastic
as an ice-age. Secondly homo is only a minor
variation on its predecessors (and no one has
a clear idea as to where to draw the line).
Thirdly, the ice-ages were a succession of
disasters, a bad time for everyone, and little
good resulted from them. Fourthly, you're
missing the element that made hominin
evolution different -- the taxon had one -- and
only one -- outstanding ability: its intelligence.
Unless you can set out some specific inter-
action of that feature with the drastic change
in climate, you are only emitting hot air.

> Sea levels dropped as the
> glaciers group -- by hundreds of feet -- and our ancestors
> spread far & wide.

They didn't do it as a result of the highly
unpleasant change in climate.

> The glacial/interglacial cycle is the real climate change. It
> turned places like the Sahara Desert, the Levant & Saudi
> Arabia verdant, and then made them deserts... forcing
> migrations... forcing adaptations...

Excess populations are produced in good
times, and it's those which migrate. The
only thing that gets 'forced' by disasters
is an increased death rate.

> This is the engine of human evolution!

It would be useful if you could explain
what brought about ice-ages (and it wasn't
anything extra-terrestrial). Milankovitch
cycles could scarcely be less significant.
But even if they were large enough, they
don't match observed climatic variations.

littor...@gmail.com wrote:

> Simple geography:
>
> Miocene hominoids lived in coastal forests of Tethys & para-Tethys seas:
> vertical waders-climbers,
> google "aquarboreal",
> then
> -hominid/pongid split = Mesopotamian Seaway closure, c 15 Ma
> -hominids along Red Sea:
> --Rift after c 8 Ma: Gorilla-Praeanthropus afarensis-aethiopicus-boisei...
> --Homo/Pan split c 5 Ma:

As I've pointed out many, many, many times, that's utterly baseless. The
best dating we have is less than 4 million years. Molecular dating
exaggerates ages and even going by the y chromosome it happened LESS
THEN 5 million years ago. But the y chromosome was under HEAVY selective
pressures, accumulating changes rapidly and not at any ridiculous "Clock Like"
rate. So, it was even more recent.

Please stop repeating the same divergence date, so dogmatically, when the
only evidence we have says it's wrong, it's too old.

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https://jtem.tumblr.com/post/656035838632837120

Paul Crowley wrote:

> Splitting events are common and usually trivial.
> The Congo River apparently changed course
> ~2 ma, splitting chimps into pan.troglodytes and
> the bonobo.

So two million years of separation and, at best, we're talking
"sub species" and not even speciation.

You see the point?

Applying the same model to humans and not only is erectus
the same species as us, but Habilis as well.

So your 2 million year divide is furthering my point: We need
something to explain the divergence. It's not at all similar to
Chimp/Bonobo, it's a clear break -- different species!

> > The ice age, the glacial/interglacial cycle which aligns
> > just about perfectly with the Homo line is exactly the
> > kind of thing I'd want to see.

> Firstly, there was no need for anything as drastic
> as an ice-age.

But there is an ice age. Whether we needed it or not, here it
is!

And going by your Bonobo/Chimp model, we do need something
quite drastic. Some 2 million years hasn't been enough to result
in two Unambiguous species.So absolutely positively without a
doubt: We need something more drastic.

> Secondly homo is only a minor
> variation on its predecessors (and no one has
> a clear idea as to where to draw the line).

LCA = Last Common Ancestor with Pan.

I'm not disputing the fact that everything from Erectus onward may
be one species.
> Thirdly, the ice-ages were a succession of
> disasters, a bad time for everyone, and little
> good resulted from them.

The ice age is characterized by a glacial/interglacial cycle which
continues today. We live inside the Holocene, an interglacial, and
we're already overdue to watch it end.

Selective pressures result in evolution. The glacial/interglacial
cycle provided selective pressures. It transformed whole ecosystems.
It created & destroyed vast treks of land. It connected and then
isolated groups. All of this was pressure, selective pressure:

ADAPT OR DIE!

It is what fueled human evolution. Period.

Fourthly, you're
> missing the element that made hominin
> evolution different -- the taxon had one -- and
> only one -- outstanding ability: its intelligence.

You're describing Homo. I'm asking about the common ancestor, when
Homo & Pan were one and the same. There was no advantages. None.

No intelligence on one side that was absent from the other.

A single species. AND THEN it split.

Your "advantage" only occurred after that happened.

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https://jtem.tumblr.com/post/656035838632837120

Op woensdag 7 juli 2021 om 22:38:36 UTC+2 schreef I Envy JTEM:

> > Simple geography:
> > Miocene hominoids lived in coastal forests of Tethys & para-Tethys seas:
> > vertical waders-climbers,
> > google "aquarboreal",
> > then
> > -hominid/pongid split = Mesopotamian Seaway closure, c 15 Ma
> > -hominids along Red Sea:
> > --Rift after c 8 Ma: Gorilla-Praeanthropus afarensis-aethiopicus-boisei...
> > --Homo/Pan split c 5 Ma:

> As I've pointed out many, many, many times, that's utterly baseless.

As I've pointed out many times, it's firmly proven, google
"ape human evolution made easy PPT verhaegen"
and read our papers, e.g.
1987 Nature 325:305-6 "Origin of hominid bipedalism"
1990 Hum Evol 5:295-7 "African ape ancestry"
1994 Hum Evol 9:121-139 "Australopithecines: ancestors of the African apes?"
1996 Hum Evol 11:35-41 "Morphological distance between australopithecine, human and ape skulls"
2000 with P-F Puech Hum Evol 15:175-186 "Hominid lifestyle and diet reconsidered: paleo-environmental and comparative data"
2002 with P-F Puech & S Munro Trends Ecol Evol 17:212-7 "Aquarboreal ancestors?"

littor...@gmail.com wrote:

> > As I've pointed out many, many, many times, that's utterly baseless.
> As I've pointed out many times, it's firmly proven, google
> "ape human evolution made easy PPT verhaegen"

If you think citing yourself is proof, you should be a professor of paleo
anthropology. Maybe, dean of a paleo anthropology department.

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https://jtem.tumblr.com/post/656099173775589376