Paleoecological evidence for environmental specialization in
Paranthropus boisei compared to early Homo

https://doi.org/10.1016/j.jhevol.2023.103325

Abstract

Since the discovery of Paranthropus boisei alongside early Homo at
Olduvai Gorge and East Turkana, paleoanthropologists have attempted to
understand the different evolutionary paths of these two hominin
lineages. Conventional wisdom is that their prolonged phase of
sympatry in eastern Africa reflects different adaptive strategies,
with early Homo characterized as the ecologically flexible generalist
and Paranthropus as the less versatile specialist. If correct, this
should imply differences in their use of ancient environments, with
early Homo occurring in a broader range of environmental contexts than
Paranthropus. This prediction has yet to be subject to rigorous
quantitative evaluation. In this study, we use the 2.0–1.4 Ma fossil
bovid assemblages associated with early Homo and P. boisei at East
Turkana (Kenya) to quantify the breadth of their environmental
associations. We find that early Homo occurs in faunal assemblages
indicative of a broader range of environments than P. boisei. A null
model taking sampling into account shows that the broad environmental
associations of early Homo are indistinguishable from random, whereas
P. boisei is one of just a handful of large mammal taxa from East
Turkana that has a narrower range of environmental associations than
expected by chance. These results support the characterization of P.
boisei as an ecological specialist relative to the more generalist
Homo. Moreover, the narrow environmental associations observed of P.
boisei, unlike those of almost all other C4 grass-consumers in the
Turkana Basin, suggest that it likely did not feed on a spatially
widespread C4 resource like the leaves, seeds, or rhizomes of grass.

Look at those massive jaws:
https://www.dlt.ncssm.edu/tiger/360views/Hominid_Skull-A_boisei_OH-5_withJaw_1200x900/index.html

Paleoecological evidence for environmental specialization in Paranthropus boisei compared to early Homo
Kaedan O'Brien cs 2023 accepted JHE
doi org/10.1016/j.jhevol.2023.103325
kaedan.obrien@anthro.utah.edu

Since the discovery of Par.boisei alongside early Homo at Olduvai Gorge & E..Turkana, PAs have attempted to understand the different evolutionary paths of these 2 hominin lineages.
Conventional wisdom: their prolonged phase of sympatry in E-Africa reflects different adaptive strategies:
- early Homo as the ecologically flexible generalist,
- Paranthropus as the less versatile specialist.
If correct, this should imply differences in their use of ancient environments:
early Homo occurred in a broader range of environmental contexts than Paranthropus.
This prediction has yet to be subject to rigorous quantitative evaluation.
In this study, we use the 2.0–1.4 Ma fossil bovid assemblages associated with early Homo & P.boisei at E.Turkana, to quantify the breadth of their environmental associations.
We find:
early Homo occurs in faunal assemblages indicative of a broader range of environments than P.boisei.
A 0-model taking sampling into account shows:
- the broad environmental associations of early Homo are indistinguishable from random,
- P.boisei is one of just a handful of large mammal taxa from E.Turkana that has a narrower range of environmental associations than expected by chance.
These results support the characterization of P.boisei as an ecological specialist vs the more generalist Homo.
The narrow environmental associations observed of P.boisei (vs almost all other C4 grass-consumers in the Turkana Basin) suggest:
it likely did not feed on a spatially widespread C4 resource, like the leaves, seeds, or rhizomes of grass.

> Look at those massive jaws:
> https://www.dlt.ncssm.edu/tiger/360views/Hominid_Skull-A_boisei_OH-5_withJaw_1200x900/index.html

Yes, no doubt boisei fed mostly on AHV (aquatic herbaceous vegetation):
"Paleo-environmental, dento-gnathic, micro-wear and isotopic data independently suggest that East-African australopiths, not unlike extant lowland gorillas in forest bais, might frequently have fed partly or largely on papyrus sedges in the swamps where their fossils lay (Puech et al. 1986, Conroy 1990, Puech 1992, van der Merwe et al. 2008, Stewart 2010, Sponheimer et al. 2013)."

Parallel evolution:
Praeanthropus (fossil subgenus of Gorilla) boisei // Australopithecus (fossil subgenus of Pan) robustus,
e.g. google
- "gorilla wading"
- "Hum.Evol. Verhaegen".
:-)

Pandora wrote:

> Paleoecological evidence for environmental specialization in
> Paranthropus boisei compared to early Homo

"Much ado about nothing."

I mean, with a thousand times the evidence and a century
more time to work things out, they couldn't figure out that
Neanderthals and so called "Moderns" lived in the same
place at the same time, never mind did the nasty. But they
can ascertain the ecological niche of hominin, with
astounding accuracy, given five minutes and a small
number of tea leafs.

Seriously. Get some "Perspective."

That's my standard advice when anyone wants to leap on
bold claims. Sit down and think: What would YOU want to
see for evidence to determine this stuff, given a best case
scenario. The point of course is that if you can do this, you
will see just how far removed these "Studies" are from
anything you can think of that would settle such matters.

-- --

https://jtem.tumblr.com/post/709568730822311936

On Fri, 17 Feb 2023 11:46:34 -0800 (PST), "littor...@gmail.com"
<littoral.homo@gmail.com> wrote:

>> Look at those massive jaws:
>> https://www.dlt.ncssm.edu/tiger/360views/Hominid_Skull-A_boisei_OH-5_withJaw_1200x900/index.html
>
>Yes, no doubt boisei fed mostly on AHV (aquatic herbaceous vegetation):
>"Paleo-environmental, dento-gnathic, micro-wear and isotopic data independently
>suggest that East-African australopiths, not unlike extant lowland gorillas in forest bais,
>might frequently have fed partly or largely on papyrus sedges in the swamps where
>their fossils lay (Puech et al. 1986, Conroy 1990, Puech 1992, van der Merwe et al. 2008,
>Stewart 2010, Sponheimer et al. 2013)."

The high C4 isotopic signal in their teeth suggest they may have been
graminivorous (most aquatic vegetation is C3), but their low-crowned
bunodont molars suggest they were not (the typical graminivore has
hypsodont dentition, high-crowned and sharply crested).
Their consistent association with other C4-feeders such as the grazing
pig Metridiochoerus (giant warthog) and Theropithecus suggest grassy
environments.

And why did P. boisei disappear from the fossil record after ~1.3 Ma?
https://www.nature.com/articles/s41598-021-86642-z

> >> Look at those massive jaws:
> >> https://www.dlt.ncssm.edu/tiger/360views/Hominid_Skull-A_boisei_OH-5_withJaw_1200x900/index.html

> >Yes, no doubt boisei fed mostly on AHV (aquatic herbaceous vegetation):
> >"Paleo-environmental, dento-gnathic, micro-wear and isotopic data independently
> >suggest that East-African australopiths, not unlike extant lowland gorillas in forest bais,
> >might frequently have fed partly or largely on papyrus sedges in the swamps where
> >their fossils lay (Puech et al. 1986, Conroy 1990, Puech 1992, van der Merwe et al. 2008,
> >Stewart 2010, Sponheimer et al. 2013)."

Kudu runner had no answer, of course:

> The high C4 isotopic signal in their teeth suggest they may have been
> graminivorous (most aquatic vegetation is C3), but their low-crowned
> bunodont molars suggest they were not (the typical graminivore has
> hypsodont dentition, high-crowned and sharply crested).
> Their consistent association with other C4-feeders such as the grazing
> pig Metridiochoerus (giant warthog) and Theropithecus suggest grassy
> environments.
> And why did P.boisei disappear from the fossil record after ~1.3 Ma?
> https://www.nature.com/articles/s41598-021-86642-z

Contracting eastern African C4 grasslands during the extinction of Paranthropus boisei
Rhonda L Quinn & Christopher J Lepre 2021 Scient.Rep.11, 7164
The extinction of the P.boisei estimated to just before 1 Ma occurred when C4 grasslands dominated EARS landscapes.
P.boisei has been characterized as an herbivorous C4 specialist,
paradoxically, its demise coincided with habitats favorable to its dietary ecology.
Here we report new pedogenic carbonate stable carbon δ13CPC & oxygen δ18OPC values (nodules=53, analyses=95) from an under-sampled interval (1.4–0.7 Ma) in the Turkana Basin, one of the most fossiliferous locales of P.boisei.
We combined our new results with published δ13CPC values from the EARS 3–0 Ma,
we conducted time-series analysis of woody cover (ƒWC),
we compared the EARS ƒWC trends to regional & global paleo-environmental & -climatic datasets.
Our results:
the long-term rise of C4 grasslands was punctuated by a transient, but significant increase in C3 vegetation & warmer Tps, coincident with the mid-Pleist.Transition 1.3–0.7 Ma, implicating a short-term rise in pCO2.
The contraction of C4 grasslands escalated dietary competition amongst the abundant C4-feeders, likely influencing P.boisei’s demise.