tag:blogger.com,1999:blog-7785493.post1473268907041369941..comments2024-01-04T04:11:55.717+02:00Comments on Dienekes’ Anthropology Blog: AAPA 2013 abstractsDienekeshttp://www.blogger.com/profile/02082684850093948970noreply@blogger.comBlogger12125tag:blogger.com,1999:blog-7785493.post-955329612122881912013-02-25T18:18:02.359+02:002013-02-25T18:18:02.359+02:00Maybe I am wrong, but I think female selection in ...Maybe I am wrong, but I think female selection in context with nutriment is just a byproduct of specialized societies. In traditional societies there is a lot of internal pressure and competition among females themselves/offspring, so the acceptance of a female coming from outside of their cultural realm would be low among the females already well established in a specialized society, like in a dairy producing society. So it is likely that the outsider and her offspring would have less had access to food. Would kind of explain why MS with its genetic inherited component is more common in "white" women, because this group of women would be the descendents of a well established and specialized group of females.Katharóshttps://www.blogger.com/profile/16649693310029639154noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-1542553674612660672013-02-24T13:08:19.370+02:002013-02-24T13:08:19.370+02:00Creative,
There is a clear correlation of MS with...Creative,<br /><br />There is a clear correlation of MS with lack of vitamin D. So, yes, southerners with dark skin would tend to suffer from it in the north/ foggy NW, unless they had a diet high in fish/ sea mammals or drank a lot of milk.<br /><br />However, MS is not sufficiently prevalent to cause selective pressure - it's more of a "diagnostically valuable" side-effect.eurologisthttps://www.blogger.com/profile/03440019181278830033noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-59978398687111974692013-02-23T08:29:08.728+02:002013-02-23T08:29:08.728+02:00"The decline in individual fitness of early N..."The decline in individual fitness of early Neolithic individuals relative to their Mesolithic predecessors is archaeologically obvious even at the skeletal level, therefore it’s evident these people were under strong selective pressure."<br /><br />Doesn't that show the opposite? If the neolithics were a lot less fit than the mesolithics doesn't that imply it had become easier to survive so even if you had a few physical flaws you could still get by while the H-Gs had to be more flawless to survive?<br /><br />"would reduce the R1b cultural supermen / mtDNA H superwomen, “everyone was genocidal and bred like a Pharaoh” thrust of the neutral biologically adaptive camp."<br /><br />Or maybe they could just drink milk in an environment that was good for cattle but not that great (at the time) for crops?<br />Greyhttps://www.blogger.com/profile/13398462488549380796noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-16116615703621827982013-02-22T09:55:30.754+02:002013-02-22T09:55:30.754+02:00Autoimmune diseases in general are more common in ...Autoimmune diseases in general are more common in women than in men. An example of this would be Multiple sclerosis which is more common among women further away from the equator. Kind of makes me wonder if European Mesolithic Hunter-Gatherers were also in possession of these unfavorable mutations or if the tendency to MS is the lack of appropriate adaption over time from people coming "recently" from southerly regions. Katharóshttps://www.blogger.com/profile/16649693310029639154noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-41930056728096163552013-02-21T09:39:11.755+02:002013-02-21T09:39:11.755+02:00Are there studies investigating the effect of the ...Are there studies investigating the effect of the antibodies present in milk on the immune system and immunization?<br /><br />With all the pandemics ravaging through Europe, I could see a potentially significant benefit, there.<br /><br />As to the genetic impact of Bell Beakers, let's not forget that they were only present in parts of Europe, and in central Europe, even where they were, their settlement density was very low (~10% - 20% of that of regular agriculturalists).eurologisthttps://www.blogger.com/profile/03440019181278830033noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-10356261833897541642013-02-21T09:37:25.956+02:002013-02-21T09:37:25.956+02:00@andrew
I think you missed half of my meaning. T...@andrew<br /><br />I think you missed half of my meaning. To repeat: "Population replacements are one side of the coin..."; this comment implies roughly equal weighting for two concepts. I do not deny the simple appeal of linking R1b to Bell Beaker based on the currently available evidence. Bell Beaker was clearly a dispersive phenomenon, and there are any number of isotopic studies we could reference that would support people migrating during these and earlier time periods, for example:<br />http://www.pasthorizonspr.com/index.php/archives/02/2013/confirmation-that-near-east-farmers-bring-agriculture-to-europe<br /><br />However, you are subordinating the importance of biologically adaptive fitness operating under the influence of a radical change in lifestyle and environment (i.e. as brought on by a transition to farming, a major "adaptive stress"), to the cultural advantage provided by early metallurgy and the adjusted social structure that was built along with it. The decline in individual fitness of early Neolithic individuals relative to their Mesolithic predecessors is archaeologically obvious even at the skeletal level, therefore it’s evident these people were under strong selective pressure.<br /><br />To discuss the change in haplogroup frequencies over time: Under an adaptive stress scenario the period of most rapid change in allele frequencies would be during the initial onset of the stressor, when the least advantageous genes are rapidly replaced. This is the common scenario during an epidemic, classic survival of the newly fittest. In the currently discussed case I can envision any mixed haplogroup society that adopted farming and its attendant biological stressors would strongly select for advantageous alleles during the early adaptive period. After the initial Neolithic rollover you’re left with a set of “nearly equally good” genes by the Bronze Age that can then compete with each other over time both biologically and through culture. This of course is against the backdrop of migrating, mutually competing groups you and the majority of commentators focus on.<br /><br />I would further argue against your position that minor fitness advantages, like cardiovascular health and sperm function would not be strongly selected for over time. This is admittedly challenging to quantify, however it makes sense given real-life parallels.<br /><br />In short, the biological fitness of various mtDNA and Y groups should definitely be considered. Agricultural diseases both parasitic and intrinsic are still affecting us today. This would certainly have been the case in the past, and adding the element of biological fitness would reduce the R1b cultural supermen / mtDNA H superwomen, “everyone was genocidal and bred like a Pharaoh” thrust of the neutral biologically adaptive camp.Black Taylorhttps://www.blogger.com/profile/12608950569578025238noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-56425258840274258512013-02-21T08:46:14.540+02:002013-02-21T08:46:14.540+02:00"These differences [Neandertal internal nasal..."These differences [Neandertal internal nasal dimensions are greater in both height and length than archaic humans from sub-Saharan Africa] parallel those seen in modern humans, indicating that Neandertals had an increased capacity for nasal heat and moisture exchange over their African counterparts and thus exhibit clear evidence for cold-climate adaptation". <br /><br />Are 'these differences' a result of introgression from Neanderthals or the result of subsequent evolution in Europe? It would be very interesting to know the gene(s) involved, and their ancestry. terrythttps://www.blogger.com/profile/17327062321100035888noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-29698535657016334872013-02-21T05:15:37.914+02:002013-02-21T05:15:37.914+02:00Lets not forget that not only R1b but also R1a pop...Lets not forget that not only R1b but also R1a populations have H women in the 40%.<br /><br />If anyhting I would connect mtDNA H to European R1 not only European R1b.Fantyhttps://www.blogger.com/profile/07969348276219179258noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-31143500585940703742013-02-21T03:34:06.529+02:002013-02-21T03:34:06.529+02:00@ Black Taylor.
Your analysis doesn't fit the...@ Black Taylor.<br /><br />Your analysis doesn't fit the data. Europe has current haplogroup distributions by the end of the Copper Age, more or less and then is stable. The initial Neolithic has been shown in several ancient DNA studies to be abrupt. There is good archaeological and physical anthropology evidence for an abrupt change in the Copper Age. But, sperm motility and middle age heart health improvements, even if they are present, don't have that profile, those are fitness enhancements that would provide small percentage fitness enhancements over many generations not abrupt fitness enhancements followed by statsis (besides which mtDNA may have an impact on metabolism but probably not immune function). You do see that kind of continuous fitness enhancement right into the last thousand years for lactose persistence, you don't see that for NRY-DNA and mtDNA haplogroups.<br /><br />The evidence is a much better fit to Y-DNA R1b and mtDNA H expanding as a package on the strength of Belll Beaker (including successor cultures in continuity with it) having technological, cultural and political organization advantages than it is for them expanding in frequency mostly as a result of intrinsic fitness enhancement value.andrewhttps://www.blogger.com/profile/08172964121659914379noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-33526058174077281962013-02-21T02:28:55.753+02:002013-02-21T02:28:55.753+02:00Concerning the abstract discussing mtDNA H: Popula...Concerning the abstract discussing mtDNA H: Population replacements are one side of the coin, but surely a parsimonious explanation for the rise of R1b and mtDNA H in Europe since the Mesolithic is the advantages these confer respectively in disease protection and sperm function. For instance R1b is likely under strong selective pressure for the protection it provides against coronary disease:<br /><br />http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(11)61453-0/abstract<br /><br />And mtDNA H is likely under strong selection for the protection it confers in men that have this haplogroup against low sperm motility:<br /><br />http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1287528/<br /><br />Quite simply these are advantageous alleles that may still be undergoing positive selection, rather like lactase persistence, which has been increasing in frequency even since the middle ages. It's easy to imagine how R1b would be swept to near-fixation in any farming population that consumed a lot of saturated fats and carbohydrates, at least as long as the old guys in the corners of their huts who *haven't* had heart attacks by age 50 are still of some use. Especially if their healthy mtDNA H sperm was still making some babies in their densely populated farming villages.Black Taylorhttps://www.blogger.com/profile/12608950569578025238noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-45942815851099702302013-02-20T23:15:54.682+02:002013-02-20T23:15:54.682+02:00"...the Yinxu population shows a closest gene...<i>"...the Yinxu population shows a closest genetic affinity with the populations of Dadianzi and Zhukaigou early Bronze Age sites (Inner Mongolia), but a more distant relation to the historical period populations."</i><br /><br />Interesting result and seems to reinforce something already known, that in the second millennium BCE the cultures represented at Dadianzi and Zhukaigou were either in contact with the Shang or were otherwise closely related to the Shang. Zhukaigu was apparently influenced by the Qijia culture, the most likely vector for the introduction of bronze technology into the Chinese heartland.<br /><br />In addition to possessing relatively advanced metallurgy, the Qijia bred horses and practiced oracle divination, all cultural traits that were highly developed in the Shang.Va_Highlanderhttps://www.blogger.com/profile/04671547664669092756noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-48129099544443786742013-02-20T19:36:15.552+02:002013-02-20T19:36:15.552+02:00Do you take requests? Could you remember to commen...Do you take requests? Could you remember to comment on the following study when it comes out? It looks like they tested a lot of samples, 400 mtdna and 250 y-dna, and most significantly, the abstract implies they used lots of recently found y-SNPs for determining the haplogroups.<br /><br />"Genetic analysis of some mountain communities of central Italy isolated areas." [Francesco Messina]<br /><br />Unrelated, but it looks like the All-American, Republican notation BC/AD is still hugely preferred over the liberal, Obama-voting, guilt-ridden notation BCE/CE.<br />kalupiterohttps://www.blogger.com/profile/06731880017844927329noreply@blogger.com