• The evolution of hominin bipedalism in two steps

    From Primum Sapienti@invalide@invalid.invalid to sci.anthropology.paleo on Sat Nov 15 23:07:02 2025
    From Newsgroup: sci.anthropology.paleo

    This came out in August, does not look like it's
    been posted so far

    https://www.nature.com/articles/s41586-025-09399-9

    Abstract
    Bipedalism is a human-defining trait. It is made
    possible by the familiar, bowl-shaped pelvis,
    whose short, wide iliac blades curve along the
    sides of the body to stabilize walking and
    support internal organs and a large-brained,
    broad-shouldered baby. The ilium changes
    compared with living primates are an evolutionary
    novelty. However, how this evolution came about
    remains unknown. Here, using a multifaceted
    histological, comparative genomic and functional
    genomic approach, we identified the developmental
    bases of the morphogenetic shifts in the human
    pelvis that made bipedalism possible. First, we
    observe that the human ilium cartilage growth
    plate underwent a heterotopic shift, residing
    perpendicular to the orientation present in
    other primate (and mouse) ilia. Second, we
    observe heterochronic and heterotopic shifts in
    ossification that are unlike those in non-human
    primate ilia or human long bones. Ossification
    initiates posteriorly, resides externally with
    fibroblast (and perichondral) cells contributing
    to osteoblasts, and is delayed compared with
    other bones in humans and with primate ilia.
    Underlying these two shifts are regulatory
    changes in an integrated
    chondrocyterCoperichondralrCoosteoblast pathway,
    involving complex hierarchical interactions
    between SOX9rCoZNF521rCoPTH1R and RUNX2rCoFOXP1/2.
    These innovations facilitated further growth
    of the human pelvis and the unique formation
    of the ilium among primates.
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  • From JTEM@jtem01@gmail.com to sci.anthropology.paleo on Sun Nov 16 21:32:24 2025
    From Newsgroup: sci.anthropology.paleo

    On 11/16/25 1:07 AM, Primum Sapienti wrote:
    This came out in August, does not look like it's
    been posted so far

    https://www.nature.com/articles/s41586-025-09399-9

    Abstract
    Bipedalism is a human-defining trait.


    What's important to remember is that the trait isn't
    "Human." Homo officially goes back less than 3 million
    years while fossil evidence for bipedal locomotion is
    near 7 million years old, and nobody believes that's
    when it started. The usual claim is that this dating
    is for the Homo/Pan split...

    Naledi doesn't display anything we might exact from a
    bipedal "Ancestor," including age, but it's dubbed
    "Homo." How might you explain that?
    --
    https://jtem.tumblr.com/tagged/The%20Book%20of%20JTEM/page/5
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