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  • Paranthropus boisei as an ecological specialist

    From Pandora@21:1/5 to All on Fri Feb 17 17:45:10 2023
    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

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  • From [email protected]@21:1/5 to All on Fri Feb 17 11:46:34 2023
    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
    [email protected]

    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".
    :-)

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  • From JTEM is so reasonable@21:1/5 to Pandora on Fri Feb 17 23:35:10 2023
    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

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  • From Pandora@21:1/5 to [email protected] on Sun Feb 19 14:27:29 2023
    On Fri, 17 Feb 2023 11:46:34 -0800 (PST), "[email protected]" <[email protected]> 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

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  • From [email protected]@21:1/5 to All on Sun Feb 19 11:03:42 2023
    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.

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