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Today I learned ...
Posted: Posted November 28th, 2018 by chiarizio
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Today I learned that new species can become established in a matter of centuries.
There are several related species of mouse on some island who evolved in 600 years, about.
There is a species of mosquito in the London Underground that have evolved in 150 years.

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The thing that can really speed up evolution is a genome-doubling event, or something similar if the population has already undergone a genome-doubling event.
Partial aneuploidies, in which only some chromosomes occur in increased or decreased numbers, tend to be highly disadvantageous. Whole-genome-doubling events are much less likely; but also less likely to be detrimental —— or likely to be less detrimental — if they do occur.

Then if one of a duplicated chromosome mutates, there’s probably still an unmutated version still doing its old job the old way. That makes mutations less likely to be fatal.

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The real creator of speciation is (I think) splitting the population into two or more groups who will then be isolated from each other. Usually the splitting and isolation are geographic; but it could be something else.

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Today I learned about the marriage and kinship and residency systems of the Rukuba tribe in Nigeria. Very interesting. The customs regarding second marriages are fascinating!

Edit:
https://www.encyclopedia.com/humanities/encyclopedias-almanacs-transcripts-and-maps/rukuba

Posted December 12th, 2018 by chiarizio
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bump, maybe?

Posted December 16th, 2018 by chiarizio
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Today I learned, from the Scientific American I just found in my mailbox, that:
The Tower* Black Raven prefers kipping on her back! ** She’s not dead, she’s restin’!
(And her name is Merlina. She’s one of seven.)

*of London
  • from about 1:35 to about 1:45

  • Posted December 22nd, 2018 by chiarizio
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    Today I learned about Irigwe 2ndary marriage, and how it compares and contrasts with Rukuba secondary marriage.

    https://urresearch.rochester.edu/fileDownloadForInstitutionalItem.action?itemId=6541&itemFileId=10621

    Both cultures are patrilineal and patrilocal and virilocal; yet the Rukuba very much emphasize female choice, while among the Irigwe a woman’s entire marital career is governed by her father or a “father-at-hand” (“official” father-surrogate).

    Posted December 31st, 2018 by chiarizio
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    Today I learned that new species can become established in a matter of centuries.
    There are several related species of mouse on some island who evolved in 600 years, about.


    I didn't think it would be that quick!

    Are they like dog~wolf (practically speaking species because of population separation but can interbreed) or human~bonobo (different species because even if they do tango, no offspring are made)?

    There is a species of mosquito in the London Underground that have evolved in 150 years.


    Interesting. I've read that mosquitoes can reproduce at a rate of ten generations in a year. Maybe a little less in the cool dank of the London Underground? (Or maybe more now that they're evolving to their niche!)

    That's about equivalent to 30,000 years of human activity. I don't think it will be possible for us to speciate, barring some massive cataclysm. But it is fascinating that these little critters are doing so all over the place!



    Microspecies.

    Ain't evilution wonderful!? :twisted:

    The real creator of speciation is (I think) splitting the population into two or more groups who will then be isolated from each other. Usually the splitting and isolation are geographic; but it could be something else.


    I think this is the classic example. Galapagos Island proliferation. European pygmy hippos, etc.

    The mosquitoes you mention would certainly count as isolated, but possibly still admitting of some random (train delivered) new blood.

    One wonders how many microspecies of rodents and insects there may actually be. Not just in subway tunnels, but in well established environments like old apartment complexes, hospitals, markets, sporting & entertainment venues and the like. Deep in the sub-basements of old Chicago or NYC buildings, there could be dozens or hundreds of mouse & cockroach microspecies!

    :shock:

    Posted January 8th, 2019 by elemtilas
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    One wonders how many microspecies of rodents and insects there may actually be.


    Well, I wasn’t before, but I am now!

    Posted January 8th, 2019 by chiarizio
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    You know how a thousand rainbow trout are a thousand fish, but one each of a thousand different piscine species are a thousand fishes?

    Something similar happens when pluralizing “referendum”.

    If fifty different states each have a ballot proposition all about one and the same issue, that’s fifty referendums.

    If one state has twenty-seven ballot propositions each about a different issue, that’s twenty-seven referenda.


    Posted May 5th by chiarizio
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    I never bought the "random mutations" idea. Instead of that there seems to be a lot of variety present within any particular species, and environmental differences will determine which ones appear. Things like lactase persistence don't really make sense given the existing models of evolution

    Posted May 6th by Xhin
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    Xhin
     

    If fifty different states each have a ballot proposition all about one and the same issue, that’s fifty referendums.

    If one state has twenty-seven ballot propositions each about a different issue, that’s twenty-seven referenda.


    On a similar topic, I recently learned that the correct plural of octopus actually is octopuses, or potentially octopodes. The etymology is greek, not latin. Only in latin do you pluralize -us as -i.

    Posted May 6th by Xhin
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    Xhin
     

    Or if you really want to be an asshole, don't use anything other than ὀκτώποδες.

    Posted May 6th by Xhin
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    Xhin
     
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