• Re: The taxonomy of Sahelanthropus tchadensis from a craniometric persp

    From Mario Petrinovic@21:1/5 to Pandora on Sun Aug 4 13:17:56 2024
    XPost: sci.anthropology.paleo

    On 4.8.2024. 10:38, Pandora wrote:
    Op 04-08-2024 om 00:17 schreef JTEM:
      Pandora wrote:
    It's a rather strange, counterintuitive, result that the
    cladistically most basal hominin, Sahelanthropus, is morphometrically
    closer to Homo than to Australopithecus and the great apes.

    It's not a science it's an art, an interpretation. Value
    judgments.

    Secondly, and let's be honest here, the fossil record sucks.

    No, it doesn't "have gaps," it is a gap. It's a chasm, a
    massive expanse of nothingness punctuated by the all too
    rare pieces of bone.

    Sahelanthropus is found in the wrong place. There is only the
    one individual represented. There is no basis for any
    determinations what so ever.

    Actually, there's more than one individual of this taxon, from three different localities (TM 247, TM 266 and TM 292). This additional
    material was announced in Nature in 2005:

    https://dash.harvard.edu/handle/1/3716603

    Not too far from where another hominin taxon, Australopithecus
    bahrelghazali, was discovered in 1995.

    https://www.nature.com/articles/378273a0

    If you think that's the wrong place you must have some concept of what
    is the right place. Where would that be?

    Actually, it isn't in the wrong place. Lake Megachad is at the end of
    Cameroon rift. This is very similar to lake Victoria and East-African rift.

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  • From Mario Petrinovic@21:1/5 to John Harshman on Tue Aug 6 11:50:37 2024
    XPost: sci.anthropology.paleo

    On 5.8.2024. 22:42, John Harshman wrote:
    On 8/5/24 12:00 PM, Mario Petrinovic wrote:
    On 5.8.2024. 15:28, John Harshman wrote:
    On 8/5/24 2:52 AM, Mario Petrinovic wrote:
    On 5.8.2024. 6:40, John Harshman wrote:
    On 8/4/24 8:48 PM, Mario Petrinovic wrote:
    On 4.8.2024. 20:50, John Harshman wrote:
    Don't be shy. Just say what you mean. Preferably in a single post. >>>>>>
             While we are at that, I will not be shy and I will ask >>>>>> you a question I always wanted to clear it up.
             You have two situations. In Africa you have a lot of >>>>>> separated small tribes, so high genetic diversity. In India you
    have all humans connected in one big society, so genes exchange
    among the whole population, and they average over time, so we have >>>>>> low genetic diversity. Now, the question is, in the view of
    geneticists is India the bottleneck?

    If you just waited a while before posting and thought more about
    what you wanted to say, you wouldn't have this problem. Consider that. >>>>>
    Meanwhile, I don't understand the question. India is not a
    bottleneck. What bottleneck? And you misunderstand the nature of
    African genetic diversity. Most of it is within populations, not
    between them. Africa has much higher within-population diversity
    than does the rest of the world.

             India - This is from Wikipedia: "A population bottleneck or
    genetic bottleneck is a sharp reduction in the size of a population
    due to environmental events such as famines, earthquakes, floods,
    fires, disease, and droughts; or human activities such as genocide,
    speciocide, widespread violence or intentional culling. Such events
    can reduce the variation in the gene pool of a population;
    thereafter, a smaller population, with a smaller genetic diversity,
    remains to pass on genes to future generations of offspring. Genetic
    diversity remains lower, increasing only when..." So, they say that
    India is a bottleneck, it is not me that is saying this, I know that
    India isn't a bottleneck.

    Who says that India is a bottleneck? All you have shown here is a
    definition of the term. And that definition doesn't even apply to
    India. You may be trying to say that India experienced a bottleneck
    many years ago, but even that just isn't true.

             The definition implies less diversity for less prosperous >> situation. I would say that India has more prosperous situation than
    Africa.

    The definition implies no such thing. A bottleneck is a population
    reduction to near zero. All your quote does is give some of the possible reasons for that reduction. The population of India is huge and has been
    for a very long time. No bottleneck. The reasons why Africa has more
    genetic diversity than the rest of the world (not just India) are likely
    to be that a small sub-population of modern humans left Africa and
    rapidly expanded. Rapid expansion doesn't create genetic variation,
    which remains at the level of the founder population for a long time.

             Look, I am a retired train driver (who excellently
    understood simple mathematics when he was kid), I do understand that
    in homogeneous population genes average. How come scientists have a
    complete lack of understanding of this, and why their logic is so
    simple that even kids in kindergarten would be ashamed of it, is
    beyond me. In other words, when humans are the most advanced, when
    they have multiple trading connections, when they all live *as one*,
    then they have the least genetic variation. In other words, what in
    real life is the most prosperous situation scientists describe as
    the least prosperous situation. In the most prosperous situation
    humans advance, which is only logical. But scientists postulate that
    in the least prosperous situation humans advance. How come? There is
    few people, and then comes God and does his magic, and that magic
    advances those few.

    Maybe scientists understand something you don't. Maybe your
    understanding here is just wrong. You are confusing a lack of
    geographically structured variation with a lack of individual
    variation. Do you even read what I say?

             I read what you say, if this is the right meaning for what I
    am doing, don't worry about it.

    ???

    ??? Yes, I do read you.

             Africa - Yes, of course, this is how variation emerges, you
    receive influxes from outside, and those influxes create genetic
    diversity.

    That has almost nothing to do with the variation within Africa.

    In a homogeneous population, without outside influxes, Actually, if
    those outside influxes are very small compared to your big size, you
    cannot have diversity. So, In Africa you have multiple (because they
    are separated) sources of genes, which receive, from time to time,
    influxes from other separated sources.
             In other words, more separation, more genetic diversity, >>>> less separation, less genetic diversity. More separation equals less
    prosperous world, less separation equals prosperous world, just like
    we have today. Scientists turned everything upside down, and there
    isn't a single one among them who understands this.
             So, to have genetic variation you got to have a lot of >>>> similar sizes separated gene pools. If you have a single gene pool
    there is no variation.

    This is just nonsense.

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