<?xml version="1.0" encoding="UTF-8"?><rss version="2.0"
	xmlns:content="http://purl.org/rss/1.0/modules/content/"
	xmlns:dc="http://purl.org/dc/elements/1.1/"
	xmlns:atom="http://www.w3.org/2005/Atom"
	xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
		>
<channel>
	<title>Comments on: Re-imagining genetic variation</title>
	<atom:link href="http://blogs.discovermagazine.com/gnxp/2012/09/re-imagining-genetic-variation/feed/" rel="self" type="application/rss+xml" />
	<link>http://blogs.discovermagazine.com/gnxp/2012/09/re-imagining-genetic-variation/</link>
	<description></description>
	<lastBuildDate>Mon, 20 May 2013 22:01:00 +0000</lastBuildDate>
	<sy:updatePeriod>hourly</sy:updatePeriod>
	<sy:updateFrequency>1</sy:updateFrequency>
	<generator>http://wordpress.org/?v=3.4.2</generator>
	<item>
		<title>By: Emil</title>
		<link>http://blogs.discovermagazine.com/gnxp/2012/09/re-imagining-genetic-variation/#comment-47115</link>
		<dc:creator>Emil</dc:creator>
		<pubDate>Wed, 03 Oct 2012 02:10:17 +0000</pubDate>
		<guid isPermaLink="false">http://blogs.discovermagazine.com/gnxp/?p=18476#comment-47115</guid>
		<description>Very cool data indeed! Perhaps I should get more into pop gen., so I can understand more of the technicalities. Unfortunately, I&#039;m too interested in other things, and time is limited. However, I intend to read https://en.wikipedia.org/wiki/The_10,000_Year_Explosion soon(ish).</description>
		<content:encoded><![CDATA[<p>Very cool data indeed! Perhaps I should get more into pop gen., so I can understand more of the technicalities. Unfortunately, I&#8217;m too interested in other things, and time is limited. However, I intend to read <a href="https://en.wikipedia.org/wiki/The_10,000_Year_Explosion" rel="nofollow">https://en.wikipedia.org/wiki/The_10,000_Year_Explosion</a> soon(ish).</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: Eurologist</title>
		<link>http://blogs.discovermagazine.com/gnxp/2012/09/re-imagining-genetic-variation/#comment-47114</link>
		<dc:creator>Eurologist</dc:creator>
		<pubDate>Thu, 27 Sep 2012 07:21:00 +0000</pubDate>
		<guid isPermaLink="false">http://blogs.discovermagazine.com/gnxp/?p=18476#comment-47114</guid>
		<description>&lt;i&gt;3-d plots are when i have a 3-d printer&lt;/i&gt;

Rotating the view and making an animated .gif or similar seems to work quite well in many instances.</description>
		<content:encoded><![CDATA[<p><i>3-d plots are when i have a 3-d printer</i></p>
<p>Rotating the view and making an animated .gif or similar seems to work quite well in many instances.</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: Razib Khan</title>
		<link>http://blogs.discovermagazine.com/gnxp/2012/09/re-imagining-genetic-variation/#comment-47113</link>
		<dc:creator>Razib Khan</dc:creator>
		<pubDate>Wed, 26 Sep 2012 23:08:34 +0000</pubDate>
		<guid isPermaLink="false">http://blogs.discovermagazine.com/gnxp/?p=18476#comment-47113</guid>
		<description>#11, there are several options. some of the subsetting is an artifact of human cultural classification. e.g., ethiopian jews are a subset of ethiopians, because they tend to be sampled from a the peoples of northern ethiopian highlands. some of it is simply that you have some populations which are genetically homogeneous, and so have a &#039;small circle,&#039; and happen to just lay along the same axis as a more diffuse group.

&lt;i&gt;One way to interpret the plot might be that PCA is representing everyone as admixed between three idealized populations&lt;/i&gt;

this is not really right, but goes in the right direction. don&#039;t confuse this for mode-based clustering, which does assume &#039;pure&#039; populations in many cases. the other dimensions are in the results.</description>
		<content:encoded><![CDATA[<p>#11, there are several options. some of the subsetting is an artifact of human cultural classification. e.g., ethiopian jews are a subset of ethiopians, because they tend to be sampled from a the peoples of northern ethiopian highlands. some of it is simply that you have some populations which are genetically homogeneous, and so have a &#8216;small circle,&#8217; and happen to just lay along the same axis as a more diffuse group.</p>
<p><i>One way to interpret the plot might be that PCA is representing everyone as admixed between three idealized populations</i></p>
<p>this is not really right, but goes in the right direction. don&#8217;t confuse this for mode-based clustering, which does assume &#8216;pure&#8217; populations in many cases. the other dimensions are in the results.</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: petrelharp</title>
		<link>http://blogs.discovermagazine.com/gnxp/2012/09/re-imagining-genetic-variation/#comment-47112</link>
		<dc:creator>petrelharp</dc:creator>
		<pubDate>Wed, 26 Sep 2012 23:04:39 +0000</pubDate>
		<guid isPermaLink="false">http://blogs.discovermagazine.com/gnxp/?p=18476#comment-47112</guid>
		<description>What do you think it means that &quot;some groups are clearly subsets of other groups in their distribution&quot;?  It probably does not mean that the genetic variation in one is a subset of the other -- quite different groups could get squished into the same area by the projection down onto two dimensions, no?  One way to interpret the plot might be that PCA is representing everyone as admixed between three idealized populations, the vertices of the triangle; so groups that are quite different but share the same admixture coordinates for those populations (even if they have another important chunk of ancestry) would end up in the same place.

Thoughts?  Investigations?</description>
		<content:encoded><![CDATA[<p>What do you think it means that &#8220;some groups are clearly subsets of other groups in their distribution&#8221;?  It probably does not mean that the genetic variation in one is a subset of the other &#8212; quite different groups could get squished into the same area by the projection down onto two dimensions, no?  One way to interpret the plot might be that PCA is representing everyone as admixed between three idealized populations, the vertices of the triangle; so groups that are quite different but share the same admixture coordinates for those populations (even if they have another important chunk of ancestry) would end up in the same place.</p>
<p>Thoughts?  Investigations?</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: Razib Khan</title>
		<link>http://blogs.discovermagazine.com/gnxp/2012/09/re-imagining-genetic-variation/#comment-47111</link>
		<dc:creator>Razib Khan</dc:creator>
		<pubDate>Wed, 26 Sep 2012 18:27:25 +0000</pubDate>
		<guid isPermaLink="false">http://blogs.discovermagazine.com/gnxp/?p=18476#comment-47111</guid>
		<description>#9, i&#039;ll check when i get home. most of the variance was in the first 2 components from what i recall. not much in the 3rd (did 3 by 1 plot too).</description>
		<content:encoded><![CDATA[<p>#9, i&#8217;ll check when i get home. most of the variance was in the first 2 components from what i recall. not much in the 3rd (did 3 by 1 plot too).</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: neuroecology</title>
		<link>http://blogs.discovermagazine.com/gnxp/2012/09/re-imagining-genetic-variation/#comment-47110</link>
		<dc:creator>neuroecology</dc:creator>
		<pubDate>Wed, 26 Sep 2012 16:40:32 +0000</pubDate>
		<guid isPermaLink="false">http://blogs.discovermagazine.com/gnxp/?p=18476#comment-47110</guid>
		<description>Out of curiosity, what % of the variance is accounted for by the first two components in your sample?  How does it look when presented as a 3 dimensional pca plot?</description>
		<content:encoded><![CDATA[<p>Out of curiosity, what % of the variance is accounted for by the first two components in your sample?  How does it look when presented as a 3 dimensional pca plot?</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: Razib Khan</title>
		<link>http://blogs.discovermagazine.com/gnxp/2012/09/re-imagining-genetic-variation/#comment-47109</link>
		<dc:creator>Razib Khan</dc:creator>
		<pubDate>Wed, 26 Sep 2012 15:52:19 +0000</pubDate>
		<guid isPermaLink="false">http://blogs.discovermagazine.com/gnxp/?p=18476#comment-47109</guid>
		<description>#7, check the email you provided on your comment.</description>
		<content:encoded><![CDATA[<p>#7, check the email you provided on your comment.</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: Santiago</title>
		<link>http://blogs.discovermagazine.com/gnxp/2012/09/re-imagining-genetic-variation/#comment-47108</link>
		<dc:creator>Santiago</dc:creator>
		<pubDate>Wed, 26 Sep 2012 15:47:02 +0000</pubDate>
		<guid isPermaLink="false">http://blogs.discovermagazine.com/gnxp/?p=18476#comment-47108</guid>
		<description>Yes, procrustes analysis would be the first step: finding the (linear + translation) transformation that minimizes deviation. What I want to do is more extreme. The second step would be non-linear isomorphic transformation. As your post shows and the article mentions, Europe will be less deformed. Geographic disruptions such as the Himalayas or the Great Rift Valley will be dramatically seen in the map. If I try to do this, would you help me?</description>
		<content:encoded><![CDATA[<p>Yes, procrustes analysis would be the first step: finding the (linear + translation) transformation that minimizes deviation. What I want to do is more extreme. The second step would be non-linear isomorphic transformation. As your post shows and the article mentions, Europe will be less deformed. Geographic disruptions such as the Himalayas or the Great Rift Valley will be dramatically seen in the map. If I try to do this, would you help me?</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: Razib Khan</title>
		<link>http://blogs.discovermagazine.com/gnxp/2012/09/re-imagining-genetic-variation/#comment-47107</link>
		<dc:creator>Razib Khan</dc:creator>
		<pubDate>Wed, 26 Sep 2012 15:23:21 +0000</pubDate>
		<guid isPermaLink="false">http://blogs.discovermagazine.com/gnxp/?p=18476#comment-47107</guid>
		<description>http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1002886</description>
		<content:encoded><![CDATA[<p><a href="http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1002886" rel="nofollow">http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1002886</a></p>
]]></content:encoded>
	</item>
	<item>
		<title>By: Santiago</title>
		<link>http://blogs.discovermagazine.com/gnxp/2012/09/re-imagining-genetic-variation/#comment-47106</link>
		<dc:creator>Santiago</dc:creator>
		<pubDate>Wed, 26 Sep 2012 14:59:18 +0000</pubDate>
		<guid isPermaLink="false">http://blogs.discovermagazine.com/gnxp/?p=18476#comment-47106</guid>
		<description>Razib, thanks so much! this is exciting data that actually I always wanted (I&#039;m a fan of Cavalli-Sforza work).

What I want to do here is to visualize the scatter but allowing to shift positions to geographic coordinates (by interpolating). I will do this using an interactive scatter that allows user to focus on regions, similar to what I&#039;ve done here: http://moebio.com/research/wikipediagender yet allowing zoom in any chosen coordinate

Other interesting approach is to draw inverse geographic distances with lines (geo closeness network)… and the opposite, draw the genetic closeness network when point are placed on geographic positions.

Finally it would be fantastic to use PC1/PC2 coordinates to place populations and then perform a continual deformation of the geographic coordinates space in order to make the regions cover their population spots. That would be a new genetics-driven geographical projection. I love space deformations a la D&#039;Arcy Thompson or a la Einstein/Poincaré  and I&#039;ve already worked on some deformed maps, look: http://moebio.com

What do you think of these ideas?</description>
		<content:encoded><![CDATA[<p>Razib, thanks so much! this is exciting data that actually I always wanted (I&#8217;m a fan of Cavalli-Sforza work).</p>
<p>What I want to do here is to visualize the scatter but allowing to shift positions to geographic coordinates (by interpolating). I will do this using an interactive scatter that allows user to focus on regions, similar to what I&#8217;ve done here: <a href="http://moebio.com/research/wikipediagender" rel="nofollow">http://moebio.com/research/wikipediagender</a> yet allowing zoom in any chosen coordinate</p>
<p>Other interesting approach is to draw inverse geographic distances with lines (geo closeness network)… and the opposite, draw the genetic closeness network when point are placed on geographic positions.</p>
<p>Finally it would be fantastic to use PC1/PC2 coordinates to place populations and then perform a continual deformation of the geographic coordinates space in order to make the regions cover their population spots. That would be a new genetics-driven geographical projection. I love space deformations a la D&#8217;Arcy Thompson or a la Einstein/Poincaré  and I&#8217;ve already worked on some deformed maps, look: <a href="http://moebio.com" rel="nofollow">http://moebio.com</a></p>
<p>What do you think of these ideas?</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: Razib Khan</title>
		<link>http://blogs.discovermagazine.com/gnxp/2012/09/re-imagining-genetic-variation/#comment-47105</link>
		<dc:creator>Razib Khan</dc:creator>
		<pubDate>Wed, 26 Sep 2012 14:36:09 +0000</pubDate>
		<guid isPermaLink="false">http://blogs.discovermagazine.com/gnxp/?p=18476#comment-47105</guid>
		<description>3-d plots are when i have a 3-d printer ;-)</description>
		<content:encoded><![CDATA[<p>3-d plots are when i have a 3-d printer <img src='http://blogs.discovermagazine.com/gnxp/wp-includes/images/smilies/icon_wink.gif' alt=';-)' class='wp-smiley' /> </p>
]]></content:encoded>
	</item>
	<item>
		<title>By: Razib Khan</title>
		<link>http://blogs.discovermagazine.com/gnxp/2012/09/re-imagining-genetic-variation/#comment-47104</link>
		<dc:creator>Razib Khan</dc:creator>
		<pubDate>Wed, 26 Sep 2012 14:30:33 +0000</pubDate>
		<guid isPermaLink="false">http://blogs.discovermagazine.com/gnxp/?p=18476#comment-47104</guid>
		<description>merge these files.

https://www.dropbox.com/s/ar7d4u6izbexq3v/plinkmds.csv

https://www.dropbox.com/s/eqvuy11h2kgy9bm/hgdphapmapbehar.csv

i assume most of you know R, but useful:

attr(kVert,&quot;names&quot;)

inspect them and remove populations you don&#039;t want to plot (e.g., kVert[22]=NULL). &quot;friends&quot; you should remove, they&#039;re a bunch of random people (my readers &amp; friends) who create a very large circle because they&#039;re not a real population.</description>
		<content:encoded><![CDATA[<p>merge these files.</p>
<p><a href="https://www.dropbox.com/s/ar7d4u6izbexq3v/plinkmds.csv" rel="nofollow">https://www.dropbox.com/s/ar7d4u6izbexq3v/plinkmds.csv</a></p>
<p><a href="https://www.dropbox.com/s/eqvuy11h2kgy9bm/hgdphapmapbehar.csv" rel="nofollow">https://www.dropbox.com/s/eqvuy11h2kgy9bm/hgdphapmapbehar.csv</a></p>
<p>i assume most of you know R, but useful:</p>
<p>attr(kVert,&#8221;names&#8221;)</p>
<p>inspect them and remove populations you don&#8217;t want to plot (e.g., kVert[22]=NULL). &#8220;friends&#8221; you should remove, they&#8217;re a bunch of random people (my readers &amp; friends) who create a very large circle because they&#8217;re not a real population.</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: Santiago</title>
		<link>http://blogs.discovermagazine.com/gnxp/2012/09/re-imagining-genetic-variation/#comment-47103</link>
		<dc:creator>Santiago</dc:creator>
		<pubDate>Wed, 26 Sep 2012 13:21:33 +0000</pubDate>
		<guid isPermaLink="false">http://blogs.discovermagazine.com/gnxp/?p=18476#comment-47103</guid>
		<description>nice ideas, intriguing! Could you please share the data?</description>
		<content:encoded><![CDATA[<p>nice ideas, intriguing! Could you please share the data?</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: Eurologist</title>
		<link>http://blogs.discovermagazine.com/gnxp/2012/09/re-imagining-genetic-variation/#comment-47102</link>
		<dc:creator>Eurologist</dc:creator>
		<pubDate>Wed, 26 Sep 2012 08:59:38 +0000</pubDate>
		<guid isPermaLink="false">http://blogs.discovermagazine.com/gnxp/?p=18476#comment-47102</guid>
		<description>I like that.  You could fit exact ellipses (5 parameters best fit:  position, orientation, eccentricity, and scale).  Generalizing, you could fit ellipsoids in 3-D PC plots with 6 or 7 degrees of freedom.</description>
		<content:encoded><![CDATA[<p>I like that.  You could fit exact ellipses (5 parameters best fit:  position, orientation, eccentricity, and scale).  Generalizing, you could fit ellipsoids in 3-D PC plots with 6 or 7 degrees of freedom.</p>
]]></content:encoded>
	</item>
</channel>
</rss>
