I have no problem with the standard
human/hominoid phylogeny. I will set out
briefly how I see it playing out, and then
contrast it with other scenarios vaguely
presented here.

https://en.wikipedia.org/wiki/Hominidae
http://www.sci-news.com/othersciences/anthropology/hominin-origins-09634.html

1. Gibbons evolved from monkeys,
occupying a highly distinctive niche, relying
on fast brachiation through the high
canopy, necessarily losing their tails,
centralising and lengthening their spines,
and flattening their pelvises.

2. A niche opened for larger quasi-gibbons
lower in the canopy, roughly similar to that
of siamangs, from which evolved orang-
utans; (extra size is always useful when
competing for fairly dense clusters of food,
such as figs).

3. At least one version of these larger apes
-- something like a gorilla/orangutan mix --
migrated west, also diversifying into
smaller apes in Europe and Africa;

4. Chimps split off from gorillas;
5. Hominins split from chimps.

The new bipedal taxon made many drastic
adaptations; in doing so it was able to
exploit atavistic processes
https://en.wikipedia.org/wiki/Atavism
It revivified the long flexible spine and
flatter pelvis of its gibbon ancestors

https://whatmissinglink.files.wordpress.com/2014/03/spine-and-pelvis-in-gibbons-chimps-and-humans.jpg

Each split in my scenario would have
involved a physical separation of the
populations and the diversification into
quite distinct ecological niches -- nearly all
of which exist today, so that if the
populations later met, they would not
interbreed.

Note that at no stage does my scenario
involve an unknown taxon, nor its allied
niche. I'm not claiming that such a
presence in human ancestry would have
been impossible. Nor am I denying the
existence of numerous species of ape (and
several early hominin). But there is no
need to propose that any unknown ones
were our ancestors. I am opting for the
most parsimonious theory. Entities should
not be multiplied unnecessarily. I am not
proposing ANY new entities.

Many posters here seem to have very
different phylogenies. It would be useful if
they could state their views clearly. They
never do, largely IMO because they don't
have any clear views. Confusion reigns. But
I'm willing to be proved wrong on this

I wouldn't know where to start with Marc
Verhaegen. I can make little sense of
anything he ever writes here.

So first I'll set out what I THINK is Daud
Deden's scenario. I'd ask him to do it
himself, but I know that he wouldn't.

>>>> There was a break --
>>>
>>> Only in your imagination.
>>
>> I don't get this. You can't dispute that
>> a new taxon was formed, occupying a
>> very different niche. How is that not
>> 'a break'?
>
> Before LCA HP mutation, upright biped on branches & ground, afterwards, same.
>
> Later chimps needed speed so readapted quadrupedalism.

So -- as far as I can make out -- the Deden
scheme would have a bipedal slow-
climbing quasi-gibbon (S-C/B/Q-G), that
split off from an Old World monkey maybe
around 30 ma, into a niche based largely
on fallen fruit and nuts on the forest floor.
It was bipedal from the start (in some
sense) on both tree branches and on the
ground.

This slow-climbing bipedal quasi-gibbon (S-
C/B/Q-G) gave rise:
a) to fast-brachiating gibbons around 25
ma, (all guesses at likely dates are mine) to
larger apes:
b) orangutans at ~16 ma
c) to gorillas at ~8 ma
d) to chimps at ~7 ma
e) and to hominins at ~6 ma who began to
stay on the gtround using 'domeshields'

The slow-climbing quasi-gibbon (S-C/B/Q-G)
was still around when it gave rise to
hominins. Presumably it stayed up in the
trees (if not very far up)

Having served its evolutionary purposes
(as imagined by DD), the S-C/B/Q-G went
extinct. (The extinction of a taxon after it
has served its turn in the imagination of its
theorist is automatic in all daft theories of
human evolution -- including that of the
savanna theory.)

However, there are NO slow-climbing
bipedal quasi-gibbon (S-C/B/Q-G) apes
alive today (nor at any time in recorded
history) anywhere on the planet, living on
the forest floor off fruits and nuts falling
from the canopy.

What else is wrong with this phylogeny?

The list would be nearly endless, and it's
not worth getting into. But take the
cladogram of any taxon (crows, beetles,
frogs, whatever) and propose that no
branch of it came off any other branch.
Instead there was one remarkable and
very long-lived Ur-Ancestor, occupying a
niche which cannot be described, and
which left no fossils. Following DD's
phylogeny every single species shown on
the cladogram sprang directly from that
Ur-Ancestor. It then went into extinction
not leaving a trace of its own existence.

On Tuesday, August 24, 2021 at 4:47:26 PM UTC-4, Paul Crowley wrote:
> I have no problem with the standard
> human/hominoid phylogeny. I will set out
> briefly how I see it playing out, and then
> contrast it with other scenarios vaguely
> presented here.
>
> https://en.wikipedia.org/wiki/Hominidae
> http://www.sci-news.com/othersciences/anthropology/hominin-origins-09634.html
>
> 1. Gibbons evolved from monkeys,
> occupying a highly distinctive niche, relying
> on fast brachiation through the high
> canopy, necessarily losing their tails,
> centralising and lengthening their spines,
> and flattening their pelvises.

Modern hylobatids, not archaic hylobatids, show those traits.

>
> 2. A niche opened for larger quasi-gibbons
> lower in the canopy, roughly similar to that
> of siamangs, from which evolved orang-
> utans; (extra size is always useful when
> competing for fairly dense clusters of food,
> such as figs).

The population would not have split, since the food source was from ground level to canopy level.

>
> 3. At least one version of these larger apes
> -- something like a gorilla/orangutan mix --
> migrated west, also diversifying into
> smaller apes in Europe and Africa;
>
> 4. Chimps split off from gorillas;
> 5. Hominins split from chimps.

Humans & gibbons share traits not found in any African apes.

> The new bipedal taxon made many drastic
> adaptations; in doing so it was able to
> exploit atavistic processes
> https://en.wikipedia.org/wiki/Atavism
> It revivified the long flexible spine and
> flatter pelvis of its gibbon ancestors

I can't imagine why you think Homo lost the long spine and then brought it back.

> https://whatmissinglink.files.wordpress.com/2014/03/spine-and-pelvis-in-gibbons-chimps-and-humans.jpg
>
> Each split in my scenario would have
> involved a physical separation of the
> populations and the diversification into
> quite distinct ecological niches -- nearly all
> of which exist today, so that if the
> populations later met, they would not
> interbreed.

The chr 1 transfusion already did that.
>
> Note that at no stage does my scenario
> involve an unknown taxon, nor its allied
> niche. I'm not claiming that such a
> presence in human ancestry would have
> been impossible. Nor am I denying the
> existence of numerous species of ape (and
> several early hominin). But there is no
> need to propose that any unknown ones
> were our ancestors. I am opting for the
> most parsimonious theory. Entities should
> not be multiplied unnecessarily. I am not
> proposing ANY new entities.
>
> Many posters here seem to have very
> different phylogenies. It would be useful if
> they could state their views clearly. They
> never do, largely IMO because they don't
> have any clear views. Confusion reigns. But
> I'm willing to be proved wrong on this
>
> I wouldn't know where to start with Marc
> Verhaegen. I can make little sense of
> anything he ever writes here.
>
> So first I'll set out what I THINK is Daud
> Deden's scenario. I'd ask him to do it
> himself, but I know that he wouldn't.

Only if I understood your reasoning.

>
> >>>> There was a break --
> >>>
> >>> Only in your imagination.
> >>
> >> I don't get this. You can't dispute that
> >> a new taxon was formed, occupying a
> >> very different niche. How is that not
> >> 'a break'?
> >
> > Before LCA HP mutation, upright biped on branches & ground, afterwards, same.
> >
> > Later chimps needed speed so readapted quadrupedalism.
>
> So -- as far as I can make out -- the Deden
> scheme would have a bipedal slow-
> climbing quasi-gibbon (S-C/B/Q-G), that
> split off from an Old World monkey maybe
> around 30 ma, into a niche

Yes

based largely
> on fallen fruit and nuts on the forest floor.

No, that was much later, with Homo.
> It was bipedal from the start (in some
> sense) on both tree branches and on the
> ground.

Yes, the origin of habitual orthograde bipedalism on branches, though not yet obligate orthograde bipedalism.

> This slow-climbing bipedal quasi-gibbon (S-
> C/B/Q-G) gave rise:
> a) to fast-brachiating gibbons around 25
> ma,

I do not date that, gradually hylobatids increased their speed and arm length

(all guesses at likely dates are mine) to
> larger apes:
> b) orangutans at ~16 ma
> c) to gorillas at ~8 ma
> d) to chimps at ~7 ma

Uncertain, but I'd guess bonobos are fastest brachiating great ape, closest to siamang, and probably most hylobatid-like before isolation.

> e) and to hominins at ~6 ma who began to
> stay on the ground using 'domeshields'

Undated, but very generally so, could be as late as 2ma.

> The slow-climbing quasi-gibbon (S-C/B/Q-G)

I do not know that code

> was still around when it gave rise to
> hominins. Presumably it stayed up in the
> trees (if not very far up)

Not enough data, but parsimoniously fast brachiation followed the split with great apes/hominins.

>
> Having served its evolutionary purposes
> (as imagined by DD), the S-C/B/Q-G went
> extinct. (The extinction of a taxon after it
> has served its turn in the imagination of its
> theorist is automatic in all daft theories of
> human evolution -- including that of the
> savanna theory.)

N/A

>
> However, there are NO slow-climbing
> bipedal quasi-gibbon (S-C/B/Q-G) apes
> alive today (nor at any time in recorded
> history) anywhere on the planet, living on
> the forest floor off fruits and nuts falling
> from the canopy.

Speculation, conclusion with insufficient data.
>
> What else is wrong with this phylogeny?
>
> The list would be nearly endless, and it's
> not worth getting into. But take the
> cladogram of any taxon (crows, beetles,
> frogs, whatever) and propose that no
> branch of it came off any other branch.
> Instead there was one remarkable and
> very long-lived Ur-Ancestor, occupying a
> niche which cannot be described, and
> which left no fossils.

Are you ignoring pliobatids & pliopithecids?

Following DD's
> phylogeny every single species shown on
> the cladogram sprang directly from that
> Ur-Ancestor. It then went into extinction
> not leaving a trace of its own existence.

Apes of small bodies & light skeletons are unlikely to fossilise well in rainforests, but pliopithecids are found from Spain to India & China, I don't know their diet, though leaves were significant.

I'm skeptical of phylogenetic cladograms which lump great apes as human 'ancestors'.

Thanks for giving a good try at understanding my claims. Not a bad effort.