Comments on: Inbreeding over time

By: David B

David B — Fri, 20 Mar 2009 12:20:46 +0000

“Outbreeding is a very recent phenomena everywhere in the Old World and South America”

It depends what you mean by ‘very recent’. In Western Europe, populations were mixed up by urbanisation in the 19th century. In Australia and New Zealand, the white population was formed by immigration from all over the British Isles. In these areas, the breakdown of traditional local inbreeding would have occurred more than a century ago. Of course, there would have been various departures from strict panmixia, but the same is true today.

By: geecee

geecee — Thu, 19 Mar 2009 22:58:53 +0000

gc’s rule

a paper that reports a pvalue or regression line without an accompanying scatterplot, boxplot, or contingency table is probably not a real result

By: p-ter

p-ter — Wed, 18 Mar 2009 20:47:15 +0000

Actually, considering the spreads one normally gets in population studies, the data are compact about the regression line. Of course the trend is very small, and the r2s pathetic, but the p values are good.

sure, i'm not really disputing the result, though it's tough to really see where the density lies in plots like this. just pointing out that the figure in the main text is quite a bit more visually striking than the actual data.

By: Bob Sykes

Bob Sykes — Wed, 18 Mar 2009 05:15:20 +0000

Actually, considering the spreads one normally gets in population studies, the data are compact about the regression line. Of course the trend is very small, and the r2s pathetic, but the p values are good.

Outbreeding is a very recent phenomena everywhere in the Old World and South America, but it is very common in North America. This may be yet another instance of American researchers confusing the peculiarities of American populations with the world. America is the great outlier.

By: Daniel MacArthur

Daniel MacArthur — Wed, 18 Mar 2009 04:57:29 +0000

Yuck… that’ll teach me to not check out the supplementary data before posting on an article.

Like you say, the result seems plausible (in fact I’d be shocked if there wasn’t SOME decrease in autozygosity over time), but it’s a good example of highly selective reporting of data. I’m a little surprised it got past the referees.

By: bioIgnoramus

bioIgnoramus — Wed, 18 Mar 2009 03:29:56 +0000

I wonder why the referees let them get off with not showing the data. In large part the science is the data; the tales we spin about data come and go.