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Post by sigurdur on Jan 30, 2018 3:39:21 GMT
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Post by missouriboy on Jan 31, 2018 20:42:00 GMT
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Post by missouriboy on Feb 22, 2018 15:46:19 GMT
Holocene fluctuations in human population demonstrate repeated links to food production and climatewww.pnas.org/content/114/49/E10524A Wealth of prehistoric climate links here. I find the archaeologists to be a much more pragmatic lot than the climate shills, Abstract We consider the long-term relationship between human demography, food production, and Holocene climate via an archaeological radiocarbon date series of unprecedented sampling density and detail. There is striking consistency in the inferred human population dynamics across different regions of Britain and Ireland during the middle and later Holocene. Major cross-regional population downturns in population coincide with episodes of more abrupt change in North Atlantic climate and witness societal responses in food procurement as visible in directly dated plants and animals, often with moves toward hardier cereals, increased pastoralism, and/or gathered resources. For the Neolithic, this evidence questions existing models of wholly endogenous demographic boom–bust. For the wider Holocene, it demonstrates that climate-related disruptions have been quasi-periodic drivers of societal and subsistence change.
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Post by missouriboy on Mar 12, 2018 19:27:31 GMT
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Post by nautonnier on Mar 12, 2018 22:53:29 GMT
The hypotheses about nuclear winters and volcanic eruption winters do not appear to be based in fact. This matches the doubt about the accuracy of assumptions on aerosols and their affects that are in CIMP5 ensemble. Perhaps these hypotheses are falsified and that in turn could mean that CIMP5 is also falsified. |
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Post by Ratty on Mar 13, 2018 1:12:33 GMT
The hypotheses about nuclear winters and volcanic eruption winters do not appear to be based in fact. This matches the doubt about the accuracy of assumptions on aerosols and their affects that are in CIMP5 ensemble. Perhaps these hypotheses are falsified and that in turn could mean that CIMP5 is also falsified. Is there an 'H' missing somewhere? |
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Post by missouriboy on Mar 13, 2018 2:59:40 GMT
The hypotheses about nuclear winters and volcanic eruption winters do not appear to be based in fact. This matches the doubt about the accuracy of assumptions on aerosols and their affects that are in CIMP5 ensemble. Perhaps these hypotheses are falsified and that in turn could mean that CIMP5 is also falsified. Is there an 'H' missing somewhere? CHIMP5? And if falsified becomes CHUMP5? |
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Post by missouriboy on Apr 12, 2018 14:45:19 GMT
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Post by missouriboy on Sept 23, 2018 19:08:10 GMT
The abrupt climate change near 4,400 yr BP on the cultural transition in Yuchisi, China and its global linkage
www.nature.com/articles/srep27723TRIVIA ON GENETIC MUTATIONS I have been looking at YDNA mutations again. Commercial age estimation techniques for SNP mutations on the Y-chromosome assume that such mutations are random. Archaeological site dating together with YDNA samples have provided estimates of mean SNP mutation rates ... about 1 mutation every 144 years within a given population. These are being used to date age to most recent common ancestor (TMRCA) and "likely" mutation age within the human genome tree. The technique is based on the number of unique SNPs separating modern YDNA testers (10s to 100s of samples). While such events may be random in general, I wonder if they might also be induced, in the same sense as earthquakes seem to cluster, occur at higher frequency, around periods of solar minimum. My YDNA reads Celtic ... a generic lumped term for men who test positive for the R-P312 SNP mutation. During the time period discussed in this article (~5000-4000 ybp), there appears to have been a flurry of SNP mutation activity (based on estimated ages) that resulted in the formation of R-P312, six major subclades of P312, and many subclades of those subclades. These filled out the major YDNA structure of what is referred to as the Celtic peoples. This is merely supposition without a detailed workup of all the data. 
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Post by missouriboy on Nov 25, 2018 8:33:24 GMT
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Post by missouriboy on Jan 19, 2019 16:17:04 GMT
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Post by sigurdur on Jan 19, 2019 16:57:05 GMT
Will have to wait until next month to read it.
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Post by missouriboy on Jan 27, 2019 14:21:23 GMT
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Post by glennkoks on Jan 27, 2019 17:31:54 GMT
Mitochondrial DNA indicates a substantial bottleneck in human population occurred about 71,000 years ago. Greenland ice cores indicate that bottleneck coincided with a much colder period in our climate. If it was not Toba what caused that bottleneck?
Tambora had a VEI of 7 and caused "The Year WIthout A Summer" in much of the NH so I think the evidence pointing to an exponentially bigger eruption at Toba causing the bottleneck is unreasonable.
The Year Without A Summer was probably not Global and I don't think it would be much of a reach to say that some populations of early humans did not feel the effects of Toba nearly as bad as others.
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Post by nautonnier on Jan 27, 2019 18:03:51 GMT
Well there has been a more recent VEI 8 eruption at Oruanui in the Taupo area of New Zealand. If it is just the VEI size and the aerosol impact then it should be possible to see the effect of that one too. Oruanui was only 26,500 years before present.
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