• A weakly structured stem for human origins in Africa

    From Primum Sapienti@21:1/5 to All on Wed May 17 23:17:24 2023
    https://www.nytimes.com/2023/05/17/science/human-origins-africa.html

    Study Offers New Twist in How the First Humans Evolved
    A new genetic analysis of 290 people suggests that humans
    emerged at various times and places in Africa.

    Scientists have revealed a surprisingly complex origin
    of our species, rejecting the long-held argument that
    modern humans arose from one place in Africa during one
    period in time.

    By analyzing the genomes of 290 living people,
    researchers concluded that modern humans descended from
    at least two populations that coexisted in Africa for a
    million years before merging in several independent
    events across the continent. The findings were published
    on Wednesday in Nature.

    “There is no single birthplace,” said Eleanor Scerri, an
    evolutionary archaeologist at the Max Planck Institute
    for Geoarchaeology in Jena, Germany, who was not involved
    in the new study. “It really puts a nail in the coffin of
    that idea.”

    Paleoanthropologists and geneticists have found evidence
    pointing to Africa as the origin of our species. The
    oldest fossils that may belong to modern humans, dating
    back as far as 300,000 years, have been unearthed there.
    So were the oldest stone tools used by our ancestors.

    Human DNA also points to Africa. Living Africans have a
    vast amount of genetic diversity compared with other
    people. That’s because humans lived and evolved in
    Africa for thousands of generations before small
    groups — with comparatively small gene pools — began
    expanding to other continents.
    ...





    THe Nature article is open access.



    https://www.nature.com/articles/s41586-023-06055-y
    A weakly structured stem for human origins in Africa

    Abstract
    Despite broad agreement that Homo sapiens originated
    in Africa, considerable uncertainty surrounds
    specific models of divergence and migration across
    the continent1. Progress is hampered by a shortage
    of fossil and genomic data, as well as variability
    in previous estimates of divergence times. Here we
    seek to discriminate among such models by considering
    linkage disequilibrium and diversity-based statistics,
    optimized for rapid, complex demographic inference.
    We infer detailed demographic models for populations
    across Africa, including eastern and western
    representatives, and newly sequenced whole genomes
    from 44 Nama (Khoe-San) individuals from southern
    Africa. We infer a reticulated African population
    history in which present-day population structure
    dates back to Marine Isotope Stage 5. The earliest
    population divergence among contemporary populations
    occurred 120,000 to 135,000 years ago and was preceded
    by links between two or more weakly differentiated
    ancestral Homo populations connected by gene flow
    over hundreds of thousands of years. Such weakly
    structured stem models explain patterns of
    polymorphism that had previously been attributed to
    contributions from archaic hominins in Africa. In
    contrast to models with archaic introgression, we
    predict that fossil remains from coexisting
    ancestral populations should be genetically and
    morphologically similar, and that only an inferred
    1–4% of genetic differentiation among contemporary
    human populations can be attributed to genetic
    drift between stem populations. We show that model
    misspecification explains the variation in previous
    estimates of divergence times, and argue that
    studying a range of models is key to making robust
    inferences about deep history.

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  • From JTEM is so reasonable@21:1/5 to Primum Sapienti on Thu May 18 00:17:40 2023
    Primum Sapienti wrote:

    Study Offers New Twist in How the First Humans Evolved
    A new genetic analysis of 290 people suggests that humans
    emerged at various times and places in Africa.

    This is idiocy. I usually point to the "Study" that showed how
    Europe wasn't populated until about 4k years ago.

    Of course it was continuously populated for tens of thousands
    of years. It's about what DNA survives right now...

    Look. Everyone who carries the Chromosome 11 insert, the
    "Nuclear Insert" made famous by Mungo Man has Eurasian
    ancestors going back significantly further than any supposed
    mitochondrial eve. But we only know that because of the
    insert. All the rest of the DNA is either gone or
    indistinguishable from so called "Modern" DNA.

    The point is you can look at DNA, you can tell exactly where
    and how it is different from someone else's DNA but there
    isn't a goddamn thing that tells you how it got that way.

    AND, the assumptions are proven wrong.

    Scientists have revealed a surprisingly complex origin
    of our species, rejecting the long-held argument that
    modern humans arose from one place in Africa during one
    period in time.

    The message here is: DA HUMENZ CUM FROM AFRICA!11!!!1!

    What it's saying about DNA is utter bullshit.

    By analyzing the genomes of 290 living people,
    researchers concluded that modern humans descended from
    at least two populations that coexisted in Africa for a
    million years before merging in several independent
    events across the continent.

    The Bantu Expansion was like 3,000 years ago. Really. This
    story is utter bullshit.

    “There is no single birthplace,”

    They're saying the exact opposite: Africa is that one single
    birthplace.

    So the story isn't even internally consistent.




    -- --

    https://jtem.tumblr.com/post/717611036225748992

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  • From littoral.homo@gmail.com@21:1/5 to All on Thu May 18 06:28:26 2023
    Op donderdag 18 mei 2023 om 09:17:42 UTC+2 schreef JTEM is so reasonable:

    Study Offers New Twist in How the First Humans Evolved
    A new genetic analysis of 290 people suggests that humans
    emerged at various times and places in Africa.

    This is idiocy. I usually point to the "Study" that showed how
    Europe wasn't populated until about 4k years ago.
    Of course it was continuously populated for tens of thousands
    of years. It's about what DNA survives right now...
    Look. Everyone who carries the Chromosome 11 insert, the
    "Nuclear Insert" made famous by Mungo Man has Eurasian
    ancestors going back significantly further than any supposed
    mitochondrial eve. But we only know that because of the
    insert. All the rest of the DNA is either gone or
    indistinguishable from so called "Modern" DNA.
    The point is you can look at DNA, you can tell exactly where
    and how it is different from someone else's DNA but there
    isn't a goddamn thing that tells you how it got that way.
    AND, the assumptions are proven wrong.

    Scientists have revealed a surprisingly complex origin
    of our species, rejecting the long-held argument that
    modern humans arose from one place in Africa during one
    period in time.

    The message here is: DA HUMENZ CUM FROM AFRICA!11!!!1!
    What it's saying about DNA is utter bullshit.

    By analyzing the genomes of 290 living people,
    researchers concluded that modern humans descended from
    at least two populations that coexisted in Africa for a
    million years before merging in several independent
    events across the continent.

    The Bantu Expansion was like 3,000 years ago. Really. This
    story is utter bullshit.

    “There is no single birthplace,”

    They're saying the exact opposite: Africa is that one single
    birthplace.
    So the story isn't even internally consistent.

    Yes, the "out-of-Africa" dogma is nonsense, but some of them will never learn...
    Obviously,
    - early-Miocene Hominoidea lived in S-Asian coastal & swamp forests,
    - late-Miocene hominids (HPG) lived in Red Sea swamp forests IMO,
    - Pliocene Homo lived no doubt along S-Asian coasts & rivers.
    But where H.sapiens s.s. originated (Middle East?) is still uncertain IMO.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Solving Tornadoes@21:1/5 to Primum Sapienti on Thu May 18 09:46:48 2023
    On Wednesday, May 17, 2023 at 10:17:29 PM UTC-7, Primum Sapienti wrote:
    https://www.nytimes.com/2023/05/17/science/human-origins-africa.html

    Study Offers New Twist in How the First Humans Evolved
    A new genetic analysis of 290 people suggests that humans
    emerged at various times and places in Africa.

    Scientists have revealed a surprisingly complex origin
    of our species, rejecting the long-held argument that
    modern humans arose from one place in Africa during one
    period in time.

    By analyzing the genomes of 290 living people,
    researchers concluded that modern humans descended from
    at least two populations that coexisted in Africa for a
    million years before merging in several independent
    events across the continent. The findings were published
    on Wednesday in Nature.

    “There is no single birthplace,” said Eleanor Scerri, an
    evolutionary archaeologist at the Max Planck Institute
    for Geoarchaeology in Jena, Germany, who was not involved
    in the new study. “It really puts a nail in the coffin of
    that idea.”

    Paleoanthropologists and geneticists have found evidence
    pointing to Africa as the origin of our species. The
    oldest fossils that may belong to modern humans, dating
    back as far as 300,000 years, have been unearthed there.
    So were the oldest stone tools used by our ancestors.

    Human DNA also points to Africa. Living Africans have a
    vast amount of genetic diversity compared with other
    people. That’s because humans lived and evolved in
    Africa for thousands of generations before small
    groups — with comparatively small gene pools — began
    expanding to other continents.
    ...





    THe Nature article is open access.



    https://www.nature.com/articles/s41586-023-06055-y
    A weakly structured stem for human origins in Africa

    Abstract
    Despite broad agreement that Homo sapiens originated
    in Africa, considerable uncertainty surrounds
    specific models of divergence and migration across
    the continent1. Progress is hampered by a shortage
    of fossil and genomic data, as well as variability
    in previous estimates of divergence times. Here we
    seek to discriminate among such models by considering
    linkage disequilibrium and diversity-based statistics,
    optimized for rapid, complex demographic inference.
    We infer detailed demographic models for populations
    across Africa, including eastern and western
    representatives, and newly sequenced whole genomes
    from 44 Nama (Khoe-San) individuals from southern
    Africa. We infer a reticulated African population
    history in which present-day population structure
    dates back to Marine Isotope Stage 5. The earliest
    population divergence among contemporary populations
    occurred 120,000 to 135,000 years ago and was preceded
    by links between two or more weakly differentiated
    ancestral Homo populations connected by gene flow
    over hundreds of thousands of years. Such weakly
    structured stem models explain patterns of
    polymorphism that had previously been attributed to
    contributions from archaic hominins in Africa. In
    contrast to models with archaic introgression, we
    predict that fossil remains from coexisting
    ancestral populations should be genetically and
    morphologically similar, and that only an inferred
    1–4% of genetic differentiation among contemporary
    human populations can be attributed to genetic
    drift between stem populations. We show that model
    misspecification explains the variation in previous
    estimates of divergence times, and argue that
    studying a range of models is key to making robust
    inferences about deep history.

    What is stated here dovetails with my theory in that my theory indicates that hominids would have been non-migratory, and communally territorial in that their main behavior of survival is tied to guarding garden habitat at isolated locations that were
    well watered all year round.l

    James McGinn / Genius

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