Comments on: mtDNA variation tells us of Southern Asia’s massive population growth 50,000 years ago http://anthropology.net/2008/02/05/mtdna-variation-tells-us-of-southern-asias-massive-population-growth-50000-years-ago/ Beyond bones & stones Tue, 07 Feb 2012 20:33:10 +0000 hourly 1 http://wordpress.com/ By: Does mtDNA and Y-Chromosome show different signatures of population growth? « Anthropology.net http://anthropology.net/2008/02/05/mtdna-variation-tells-us-of-southern-asias-massive-population-growth-50000-years-ago/#comment-9769 Thu, 21 Feb 2008 05:42:59 +0000 http://anthropologynet.wordpress.com/?p=679#comment-9769 [...] signatures of population growth? Jump to Comments About two weeks ago, I blogged on how variation mtDNA was used to reconstruct an idea of Pleistocene population growth. That study was very remarkable because illuminated a large 5 fold increase in South Asian [...]

]]> By: Peopling of the Americas: Three Step Model for Colonizing the Americas « Anthropology.net http://anthropology.net/2008/02/05/mtdna-variation-tells-us-of-southern-asias-massive-population-growth-50000-years-ago/#comment-9713 Thu, 14 Feb 2008 19:56:34 +0000 http://anthropologynet.wordpress.com/?p=679#comment-9713 [...] a very similar methodology, Bayesian skyline plotting, seen in a recent paper that was used to estimate prehistoric population sizes. Bayesian skyline plots are a unique approach to the coalescent modeling, the assume a single [...]

]]> By: TerryT http://anthropology.net/2008/02/05/mtdna-variation-tells-us-of-southern-asias-massive-population-growth-50000-years-ago/#comment-9650 Thu, 07 Feb 2008 22:32:06 +0000 http://anthropologynet.wordpress.com/?p=679#comment-9650 The population growth seems to coincide with the beginning of megafauna extinction. Perhaps the growth is associated with improved hunting techniques? The expansion also coincides with the apparent dating of human Y-chromosome diversification outside Africa. Perhaps all these factors are related.

Does anyone have information on megafauna extinction in India?

]]> By: krishna http://anthropology.net/2008/02/05/mtdna-variation-tells-us-of-southern-asias-massive-population-growth-50000-years-ago/#comment-9649 Thu, 07 Feb 2008 16:21:33 +0000 http://anthropologynet.wordpress.com/?p=679#comment-9649 Why is it we don’t see these population dips in the graph?

I don’t see any declines in population and only a flat period (no growth) that occurred roughly 5000 years ago in South Asia.

]]> By: Kambiz http://anthropology.net/2008/02/05/mtdna-variation-tells-us-of-southern-asias-massive-population-growth-50000-years-ago/#comment-9643 Thu, 07 Feb 2008 06:46:09 +0000 http://anthropologynet.wordpress.com/?p=679#comment-9643 Krishna, to answer your question, yes the research did reflect drops in populations. The most notable figure the authors provide is about a 2 fold decline in European populations that ended by 15,000 years ago. This is an awesome level of detail that the authors could extract from the data because at around 15,000 years ago, the global climate was becoming cooler and dryer. The the most recent ice age ended about 10,000 years ago and during this time span food animal populations seem to have declined which reciprocally correlated with human populations.

Kambiz

]]> By: Kambiz http://anthropology.net/2008/02/05/mtdna-variation-tells-us-of-southern-asias-massive-population-growth-50000-years-ago/#comment-9642 Thu, 07 Feb 2008 06:39:16 +0000 http://anthropologynet.wordpress.com/?p=679#comment-9642 Boston_mahesh, I think you’re clearly missing the point of this figure. I’m confident in assuming that, we, including the authors of this peer reviewed paper, all know the current population of the Americas is greater than 500,000,0000. Come on now…

If they were gonna be documenting population growth up ’til 20008 it would be a ridiculously exponential growth curve that would have be marked on a logarithmic scale on the y-axis. Furthermore, human populations, especially those in the Americas, didn’t exponentially grow until relatively recently, i.e. the last 200 or so years. The authors made it their goal to show the relative regional population size estimates to gain a perspective on the mode and rate of human colonization of the globe during the last 100,000 years. If you look at the units on the x-axis, they didn’t break it down to the hundreds of years… rather they were resolving changes in populations over much large spans of time, in this case 5,000 year intervals!

So, in the future, please consider first thoroughly analyzing figures before you make snarky comments about a figure severely underestimating something they wasn’t even in the scope of the original research.

Kambiz

]]> By: Boston_mahesh http://anthropology.net/2008/02/05/mtdna-variation-tells-us-of-southern-asias-massive-population-growth-50000-years-ago/#comment-9641 Thu, 07 Feb 2008 05:14:00 +0000 http://anthropologynet.wordpress.com/?p=679#comment-9641 The population of the Americas is more than 500M, however, the .JPEG graph doesn’t indicate this. The .JPEG graph severely underestimates the population of the Americas.

]]> By: krishna http://anthropology.net/2008/02/05/mtdna-variation-tells-us-of-southern-asias-massive-population-growth-50000-years-ago/#comment-9637 Wed, 06 Feb 2008 17:36:41 +0000 http://anthropologynet.wordpress.com/?p=679#comment-9637 Hi,

If the population experiences a drop for various reasons, would that be reflected in these graphs / methods?

Lets take the example of today: If south asia’s current population of 1 Billion people were to experience a drop to 50,000 due to war…and someone were to look at this data of us 1,000 years in the future, would they be able to determine that the population was 1 Billion at our time, but subsequently dropped and than started growing over time again?

]]> By: razib http://anthropology.net/2008/02/05/mtdna-variation-tells-us-of-southern-asias-massive-population-growth-50000-years-ago/#comment-9621 Wed, 06 Feb 2008 02:59:06 +0000 http://anthropologynet.wordpress.com/?p=679#comment-9621 nice. there’s prefiguration of this model in s. oppenheimer’s book ‘the real eve.’

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