Tuesday, September 11, 2018

Off To The Races -- WTI -- September 11, 2018


Later, 9:51 p.m. CDT: $70.01.

Original Post 

After hours trading:

Going to $70 again before the end of the month?

The Biology Page

I am blown away by what researchers are finding these days. First it was the color of dinosaur feathers.

Now, it's the "history" of Homo neanderthalensis and Homo sapiens: two different species, and species, by definition don't interbreed.

The book: Who We Are and How We Got Here: Ancient DNA and the New Science of the Human Past, David Reich, c. 2018.

H. neanderthalensis and H. sapiens split 100,000 years ago.
  • mitochondrial DNA (mtDNA): maternal, mother to daughter
    • high rate of mutation (at least relative to non-mtDNA)
    • relatively easy to collect from bones
    • especially high density, of all things, in the tiny bones of the inner ear (who would have thought)
  • mtDNA clearly indicates that at least "some" neanderthals and "sapiens" interbred -- producing fertile offspring
    • occurred at least 50,000 years ago in Africa
  • Now, the Denisova Cave, 2008
    • in the Atlai Mountains of Siberia
    • one of the best samples of ancient DNA ever discovered -- in a bone from a child's little finger
    • whole genome mapped
    • neither neanderthal or "sapien" -- wow
    • a new "human" -- the Denisovians
    • specifically chose that name so as not to name a new species 
  • it appears:
    • modern human lineage split from "whatever existed before" about 770,00 to 550,000 years ago
    • the other lineage, then split into Neanderthals and Denisovians between 470,000 and 380,000 years ago
    • and then this: Denisovians (Siberian) closer genetically to New Guinea than to Eurasia
  • theory
    • the Denisovians separated into two lineages between 400,000 and 280,000 years ago
    • one branch, the Australo-Denisovians: interbred with modern humans; direct ancestors of present-day New Guineans
    • the Australo-Denisovians: a "ghost population" -- known only from genetics; no identifiable skeletal remains
  • the story culminates in a population dispersal from the southeast about 14,000 years ago that spread a relatively homogeneous population across Europe and the Near East
  • [interestingly, the book on Stonehenge recently read begins 10,000 years ago -- in the same ballpark]
    • 8800 BC: first farmers spread into Europe from Anatolia (Turkey)
    • 6800 BC: the hunter-gathers disappeared; occurred rapidly once it began
    • 5000 BC: Yamnaya culture originating in central Asia swept across Europe, replacing existing populations
    • across Europe, the "Corded Ware culture"
    • these are most likely the speakers of proto-Indo-European (not the Anatolians)
    • Reich explains why the folks of the Corded Ware culture were so successful
  • plague
  • Beaker folk

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