• New study sheds light on early human hai

    From ScienceDaily@1:317/3 to All on Wednesday, March 09, 2022 21:30:48
    New study sheds light on early human hair evolution

    Date:
    March 9, 2022
    Source:
    George Washington University
    Summary:
    Researchers have examined what factors drive hair variation in a
    wild population of lemurs known as Indriidae. Specifically, the
    researchers aimed to assess the impacts of climate, body size and
    color vision on hair evolution.



    FULL STORY ==========================================================================
    Hair is an important feature of primate -- including human -- diversity
    and evolution, serving functions tied to thermoregulation, protection, camouflage and signaling. However, the evolution of wild primate hair
    remained relatively understudied until recently.


    ========================================================================== Researchers in the Primate Genomics Lab at the George Washington
    University examined what factors drive hair variation in a wild
    population of lemurs known as Indriidae. Specifically, the researchers
    aimed to assess the impacts of climate, body size and color vision on
    hair evolution. They found:
    * Sifaka lemurs, which are native to Madagascar, have denser hair
    in dry,
    open environments. The researchers believe that, like early humans,
    the lemurs' hair helps protect against the strong rays of the sun.

    * Lemurs in colder regions are more likely to have dark hair. This
    is the
    first evidence in mammals for a classic pattern in nature called
    Bogert's Rule, which states that dark colors could aid with
    thermoregulation as they help absorb heat from the sun's rays.

    * Red hair in lemurs is associated with enhanced color
    vision. According to
    the researchers, populations that can see a larger range of colors
    are more likely to have patches of red hair.

    * Multiple evolutionary pressures may act on one trait and the
    strength of
    their influence may vary between species.

    "Human hair evolution remains a mystery, largely because hair does
    not fossilize," Elizabeth Tapanes, lead author on the paper and
    a postdoctoral scholar at the University of San Diego, California,
    said. (Tapanes conducted the study while a doctoral student at GW.) "The
    lemurs we studied exhibit an upright posture like humans and live in
    a variety of ecosystems like early humans, so our results provide a
    unique window into human hair evolution." Brenda Bradley, an associate professor of anthropology who directs GW's Primate Genomics Lab and is
    a co-author on the study, explained our understanding of hair evolution
    and diversity in other primates helps us fill in the gaps of our own
    human evolutionary story.

    "Most people are intrigued by the diversity of hair on their own bodies,
    and the variety of hair types among people around the world," Bradley
    said.

    "Understanding hair patterns in non-human primates, such as these lemurs,
    may provide a comparative context for understanding how variation arose
    in human hair." The researchers note future work should focus on samples across smaller geographic or phylogenetic (family-level, genus-level)
    scales and from diverse non-human and human populations.


    ========================================================================== Story Source: Materials provided by George_Washington_University. Note:
    Content may be edited for style and length.


    ========================================================================== Journal Reference:
    1. Elizabeth Tapanes, Rachel L. Jacobs, Ian Harryman, Edward E. Louis,
    Mitchell T. Irwin, Jason M. Kamilar, Brenda J. Bradley. Hair
    phenotype diversity across Indriidae lemurs. American Journal of
    Biological Anthropology, 2022; DOI: 10.1002/ajpa.24508 ==========================================================================

    Link to news story: https://www.sciencedaily.com/releases/2022/03/220309104414.htm

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