Search Results for: paternal age

By-blows, paternal age, and all that.

Posted on January 27, 2013 by

Once upon a time, people often said that ~10% of children had a biological father other than their nominal father, usually called false paternity or nonpaternity. This notion was particularly common in sociobiological circles. There were others who thought the … Continue reading →

Posted in Genetics | 72 Comments

Paternal Age and Homosexuality

Posted on January 6, 2013 by

There’s something interesting about the paternal age effect in homosexuality – apparently there isn’t one. It certainly exists for autism, schizophrenia, manic-depression, and mental retardation, which suggests that de novo mutations play an important role in all of them. But … Continue reading →

Posted in Homosexuality | 118 Comments

Paternal Age and the Force of Mortality

Posted on September 16, 2012 by

Looking into how paternal age affects life history evolution, I took our data on survival curves of Herero males and calculated the strength of selection, that is the derivative of fitness with respect to survival, as a function of mean … Continue reading →

Posted in Uncategorized | 21 Comments

Paternal Age

Posted on August 22, 2012 by

Decode Genetics has a new report out in Nature that shows how mutations increase with age, by sequencing family trios.  They found that women contribute about 15 de novo mutations, independent of age. Men contribute more (55 on average) , … Continue reading →

Posted in Uncategorized | 48 Comments

Variable mutation rates- age of puberty

Posted on August 1, 2013 by

I’ve already talked about how high paternal age can  increase the per-year and per-generation rates.  There’s another factor that can cause  variation in the mutation rate: differences in the age of male puberty.  At least that seems likely, from what … Continue reading →

Posted in Genetics | 24 Comments

The Golden Age

Posted on November 12, 2012 by

In two recent paper,  Gerald Crabtree says two correct things.  He says that the brain is complex, depends on the correct functioning of many genes, and is thus particularly vulnerable to genetic load.  Although he doesn’t use the phrase “genetic … Continue reading →

Posted in Uncategorized | 75 Comments

Ashkenazi Ancestry revisited

Posted on September 9, 2014 by

Shai Carmi has his article out on Ashkenazi Jewish ancestry.  A few comments: First, looks like a good job, on the whole. Perhaps Carmi had special training… Second, about dates: they assume a mutation rate of 1.44 x 10-8 per … Continue reading →

Posted in Ashkenazi Jews | 113 Comments

Germline selection

Posted on February 5, 2014 by

Mutations go up with paternal age.  Generally,  the increase is nearly linear with age, but a few increase far more rapidly.  In those cases, a special mechanism is involved. One of those cases is Apert syndrome,  a nasty congenital disorder … Continue reading →

Posted in Genetics | 9 Comments

Let the good times roll?

Posted on October 1, 2013 by

A new paper in PLOS Genetics claims to have found a higher frequency of deleterious mutations in the exome of French Canadians than in the French.  French Canada was founded by a small population (effective Ne about 2900),  but I … Continue reading →

Posted in Uncategorized | 18 Comments

Mental Retardation

Posted on July 2, 2013 by

People working in the field usually divide cases into organic and familial retardation. Which may not be the best possible categories, but there you are. A fair fraction of mental retardation is caused by some kind of environmental insult: birth … Continue reading →

Posted in Uncategorized | 13 Comments