Q:
What is the definition of a transitional fossil? Are there any transitional fossils between apes and humans? If so, what are some examples of these kinds of fossils?

A:
Literally, there are no transitional *fossils* between apes & humans (*living* spp). Besides, some apes (Pan: chimp+bonobo) are closer relatives of us (Homo) than they are of the other apes: gorillas, orangs, gibbons & siamangs.
Traditional paleo-anthropologists believe australopiths are transitional between apes & ourselves. This is wrong, of course: traditional PAs anthropo- & afro-centrically only see “human ancestors” in Plio-Pleistocene Africa, but miraculously never “ape ancestors” (less grants?) although Pan & Gorilla have always lived in Africa, whereas the earliest undoubted Homo (IOW, not "Homo"?Australopithecus habilis?) come from SE.Asia!
In fact, detailed comparisons (e.g. my Hum.Evol.papers) clearly show: E.Afr..a’piths are fossil Gorilla, and S.Afr.apiths are fossil Pan: apiths are no human ancestors, as traditionally assumed, but could be called transitional:
E.African Praeanthropus afarensis->boisei evolved in parallel // to S.Afr. Australopithecus africanus->robustus: from late-Pliocene “gracile” to early-Pleistocene “robust”, IOW,
- Praeanthropus (fossil subgenus of Gorilla) is +-transitional between the HP/Gorilla LCA (last common ancestor c 8 mill.yrs ago) & extant low- or highland gorillas,
- Australopithecus (fossil subgenus of Pan) is +-transitional between the Homo/Pan LCA (c 5.4 Ma) & extant chimps or bonobos.

What happened IMO is this:
Some Miocene hominids (i.c. the ancestors of extant hominids Gorilla, Pan & Homo) lived aquarboreally, bipedally wading-climbing, in coastal forests along the incipient Red Sea (google “aquarboreal”):
- When the E.Afr.Rift began, Gorilla c 8 Ma followed the swamp forests of the Rift, splitting off from HP.
- When the Red Sea opened into the Gulf (5.4 Ma? according some, caused by the Zanclean mega-flood in the Med), H and P split: Pan initially followed the coastal forests to the right (E.Afr.coasts), and Homo to the left (S.Asian coasts, eventually as far as Java & even Flores).
From the coasts, they all (G, H, P) went inland along rivers-lakes-swamps, e.g. E.Afr.apiths // S.Afr.apiths (see above).
Comparative biology shows that early-Pleistocene Homo evolved from aquarboreal to littoral, and initially spread along the Ind.Ocean coasts, google “coastal dispersal Pleistocene Homo”.

Simple, no? :-)

littor...@gmail.com wrote:

> Q:
> What is the definition of a transitional fossil? Are there any transitional fossils between apes and humans?
> If so, what are some examples of these kinds of fossils?

Best answer I've ever heard, and it's not mine but I'm willing to pretend it is the
way some knob polishers pretend that Naledi buried their dead, is this:

ALL fossils are transitional! Evolution never stopped and never will stop. ALL
species in existence are either dead-ends or the parent species to a new
species...

> A:
> Literally, there are no transitional *fossils* between apes & humans (*living* spp). Besides, some
> apes (Pan: chimp+bonobo) are closer relatives of us (Homo) than they are of the other apes: gorillas,
> orangs, gibbons & siamangs.

Very deceptive, in a way, because Chimps (and gorillas, likely) have evolved AWAY from
a common ancestor with us. They became LESS human like over time.

> Traditional paleo-anthropologists believe australopiths are transitional between apes & ourselves.

Well the timing ain't bad. Other than that, it's where they want it to be. That's it.

> This is wrong, of course: traditional PAs anthropo- & afro-centrically only see “human ancestors” in
> Plio-Pleistocene Africa

And *Everything* is a human ancestor!

They haven't altered any of their conclusions about Naledi, for example. They dubbed it
"Homo" because it was a "Human Ancestor" and re wrote the book on evolution..

But if Naledi is Homo doesn't that require Sediba to be Homo?

> but miraculously never “ape ancestors” (less grants?) although Pan & Gorilla have always lived in
> Africa, whereas the earliest undoubted Homo (IOW, not "Homo"?Australopithecus habilis?) come
> from SE.Asia!

I'm pretty certain that the lines aren't quite as distinct as you see them, and they are
CERTAINLY not as distinct and savanna idiots need to pretend. I see them as an offshoot,
descendants of some group that pushed inland from the Waterside population. We would
expect the to be at least as different from that Waterside population as Neanderthals,
Denisovans & so called Hss were from each other. After all, they were in turn each
descended from the Waterside population...

Interbreeding with previous "Strays" would have helped make everyone different. As
would "Natural Selection" -- adapting to the local environment. And once the
Glacial/Interglacial thing was rolling along it all would have gone into overdrive...

Glacial = Connection

Interglacial = Isolation

A zillion years ago I called this a "Pump."

Glaciers grow, sea level plummets, vast stretches of new beaches open up (the
continental shelves), allowing populations/DNA/technology to flow.

Interglacials occur, sea levels rise and vast stretches of beaches are swallowed
up by the waves... isolation.

"Isolation is the engine of evolution."

Didn't you say that?

-- --

https://jtem.tumblr.com/post/702405882286391296

Op woensdag 7 december 2022 om 21:39:51 UTC+1 schreef JTEM is so reasonable:

....

> Glacial = Connection
> Interglacial = Isolation
> A zillion years ago I called this a "Pump."
> Glaciers grow, sea level plummets, vast stretches of new beaches open up (the
> continental shelves), allowing populations/DNA/technology to flow.
> Interglacials occur, sea levels rise and vast stretches of beaches are swallowed
> up by the waves... isolation.

Yes, well possible.

> "Isolation is the engine of evolution."
> Didn't you say that?

I don't remember... :-)
But yes, island populations often evolve in unexpected ways, e.g.

Plate tectonics: India approached S-Eurasia (Oligo-? early-Miocene?) = archipel formation.
Some Catarrhini then reached the islands between India & Eurasia, full of coastal forests:
they became the Hominoidea:
- much larger size,
- lost the tail = unexpected (convergence with ursids??),
- vertical & centrally-placed spine (instead of dorsal as in most tetrapods) = "bipedal"!
- very broad sternum: Hominoidea=Latisternalia!
- + broad thorax = dorsal scapulas (instead of lateral) -> + lateral arm movements!
- probably longer arms: climbing arms overhead,
- possibly also broader pelvis?
IOW, they became vertical waders-climbers, google "aquarboreal".
:-)
Obvious, no?
except to antelope runners... :-DDD