Comments on: You are a mutant!

By: Hmm

Hmm — Tue, 14 Jun 2011 22:18:12 +0000

By the way Razib: this message is for the height topic in bipedalism which is now closed.

We found that testosterone correlates negatively in Finnish men with height, weight, BMI, fat percentage and fat-less weight (i.e. body size).

You might be surprised to find that eunuchs and castrate singers are ABOVE average height, because in men, the growth of bones stops as the testosterone levels increase in puberty. Thus, you will get a baby faced, high voiced and long legged “man” when you take off testosterone. Testosterone is also used as a treatment for men who are predicted to have much more than average height and for social reasons their parents want to stunt growth.

Actually this finding is in line with the world’s penis charts, where you have some kind of negative correlation between height and penis size.

http://www.targetmap.com/viewer.aspx?reportId=3073

(East Asia is taller than much of South America today and the longest penises are in <=170 cm average male height populations in Africa and South America.)

We are actually quite surprised about these testosterone-findings as it was a new field for us. Our collaborators are showing the protecting effect of T in aging men, which is somewhat surprising as well.

By: Razib Khan

Razib Khan — Tue, 14 Jun 2011 11:35:01 +0000

#12, imagine a scenario of ‘competition via motility.’ the ‘best’ sperm of a 20 year old may always be better than the ‘best’ sperm of a 40 year old. additionally, you ignore other factors like spontaneous abortion which purges genetic load. old fathers are a bigger ‘mutational jump’ which needs to be ‘purged’ in the next generation. but because of better technologies and medicine there may not be such purging. etc.

By: Eurologist

Eurologist — Tue, 14 Jun 2011 11:11:15 +0000

“On a societal level we may be able to estimate the exact cost in terms of public health costs of rising mean age of fathers.”

I am still baffled by this. Say, for simplicity, that the total male germline mutation count is simply proportional to age (exposure and repeated duplication errors). So, then, on average the child of the 40-year-old father carries the exact same number of mutations as the grandchild of the 20-year old father and his 20-year old child. What am I missing?

By: Zig

Zig — Tue, 14 Jun 2011 04:53:08 +0000

I assume this factor of two relates to y-DNA as well?

Would this also apply to the estimated common ancestor in terms of two individuals being identical at y-DNA markers tested for genealogy?

I have 36/36 match with some men who have different family stories to mine. Either there was a non paternal event in my family or the generations to the common ancestor is not calibrated correctly at 4-6.

My grandfather knew his grandfather and he says he was from Wicklow, Ireland. They are old timey American types who go way back to colonial America.

By: miko

miko — Mon, 13 Jun 2011 11:45:45 +0000

30 mutations seems like peanuts… with sibs, that”s nothing compared to the allelic variation between them. My instinct is that you’d rarely hit coding sequence at that rate. Or maybe I missed it, are these mutations in known coding/regulatory sequence?

By: Darkseid

Darkseid — Mon, 13 Jun 2011 11:24:11 +0000

Peter, can you or someone explain further? How does that process happen? What do you mean by that?

By: Dienekes

Dienekes — Mon, 13 Jun 2011 09:56:52 +0000

The Neandertal/Denisovan papers used 6.5 millions years for human-chimp divergence, which seems reasonably close to 7 million. It’s a good idea to re-examine all papers with dates dependent on this calibration point.

By: Peter Ellis

Peter Ellis — Mon, 13 Jun 2011 07:38:14 +0000

I don’t think we can read much into the high rate of somatic mutation – I would be willing to bet significant amounts that the majority of those mutations are an artefact of deriving an immortalised cell line.

By: Razib Khan

Razib Khan — Mon, 13 Jun 2011 06:11:35 +0000

(including y-DNA, which I presume was not studied here).

the y-DNA stuff is STRs, and that’s somewhat different i think.

By: Eurologist

Eurologist — Mon, 13 Jun 2011 06:07:29 +0000

A factor of two to four lower is what many have been arguing (including y-DNA, which I presume was not studied here).

Utah is also high altitude and in addition may have a higher natural soil/water background radiation (Radon etc.) than Nigeria.

By: Razib Khan

Razib Khan — Mon, 13 Jun 2011 02:56:58 +0000

#3, most people who read this weblog.

By: Meng Bomin

Meng Bomin — Mon, 13 Jun 2011 02:56:07 +0000

I implicitly assume most people understand that they all have new genetic mutations specific and identifiable to them.

Wow. You are far more optimistic than me.

By: Darkseid

Darkseid — Mon, 13 Jun 2011 01:45:39 +0000

also, some may have seen that Kevin touched on this subject recently:
http://www.gnxp.com/wp/2011/05/25/somatic-mutations-make-twins-brain-less-similar/

By: Darkseid

Darkseid — Mon, 13 Jun 2011 00:15:39 +0000

this is why old dudes make higher amounts of autistic babies