Mythology is Gross

Genealogy of the Olympians in Greek Mythology (Wikipedia)
Genealogy of the Olympians in Greek Mythology (Wikipedia)
The authors of this encyclopedia do a good job of illustrating that myths have many variant versions.

Samuel Arbesman has a fun, if creepy, post over at Wired on calculating how inbred the Greek gods were. Previously, here at The Finch & Pea, we’ve taken on the inevitable inbreeding that must have occurred in Adam and Eve’s family, which provides some additional explanation of what exactly geneticists mean by “inbreeding coefficient” and what the consequences of inbreeding can be.

I’ve thought about taking on the genetics of the Greek gods before on these grounds, but have always gotten overly hung up on the many variants of the origin stories that often exist for each god. For the gods’ sake, Aphrodite has an origin story that has her arising as a female clone from Uranus’ castrated testicles (most likely due to the SRY gene never being expressed during development).

“…there is no support from the field of population genetics for Wade’s conjectures.”

If you are a regular patron of The Finch & Pea, you know that Nicholas Wade’s controversial book, A Troublesome Inheritance (link is to David Dobbs’ unflattering review), is a work of pseudoscience that purports to draw on the fields of human and population genetics to support a panoply of racist stereotypes. Now, a lengthy list of leaders in these fields, tired of their work being misappropriated, have signed a letter asserting:

We are in full agreement that there is no support from the field of population genetics for Wade’s conjectures. – Graham Coop, Michael Eisen, Rasmus Nielsen, Molly Przeworski & Noah Rosenberg (+134 signatories)

As Mary Carmichael notes, this is probably the first time these 139 scientists have ever agreed on anything.

*Hat tip to Daniel MacArthur.

One of world’s best ideas: the distinction between genotype and phenotype

One of the most important ideas ever is the distinction between genotype and phenotype – between our genes and the traits they influence. It seems obvious to us now, but scarcely more than 100 years ago it wasn’t, which led to a lot of confusion.

The scientist who really clarified the distinction between genotype and phenotype (and who, along with the word gene, coined these terms), was Wilhlem Johannsen. I recently wrote about Johannsen for Pacific Standard, in the context of the recent discovery of the molecular basis of a European blond allele. Here I want to show why Johannsen’s key insight dispelled so much confusion.

Johannsen summed up his views in a 1911 paper, “The Genotype Conception of Heredity.” He starts out by saying that scientists have been confused because they are thinking about apparent heredity, or the “transmission-conception” of heredity. This transmission conception, which had been around since Hippocrates and Aristotle, was that “the personal qualities of any individual organism are the true heritable elements of traits!” Continue reading “One of world’s best ideas: the distinction between genotype and phenotype”

The Red Nose Gene [Repost]

Rudolph's Family

Originally posted on 24 December 2012 when my now 5 year old was 4.

Tis the season…for my 4 year old to ask me to sing Rudolph the Red-Nosed Reindeer repeatedly during any car trip longer than 30 seconds. My apologies to anyone who gets caught in the crossfire. My singing does not get better with repetition.

My kids also love the Rankin/Bass stop animation classic film Rudolph the Red-Nosed Reindeer. As you probably have come to expect, I have had a lot of time to wonder about how two seemingly normal reindeer could have a child with a glowing nose. Classic genetics is well-equipped to deal with this problem.

Both Santa and we should be very concerned about the genetics of red reindeer noses. According to Wikipedia, the Rudolph story dates back to 1939. There have probably been quite a few foggy Christmas Eves in the intervening years. According to the Pittsburgh Zoo, reindeer typically live for 10 years in the wild. While we can expect that Santa’s reindeer do a bit better than those in the wild, it is clear that Rudolph alone would not be able to “guide Santa’s sleigh” today. Given their success breeding flying reindeer, it is not hard to imagine that Santa’s elves could generate a stable of red-nosed reindeer. How they would go about doing so would depend on how, genetically, Rudolph wound up with that first Red Nose. Continue reading “The Red Nose Gene [Repost]”

Science Caturday: One Code, Two Code…

Like a DNA nucleotide, this LOLcat is capable of playing multiple roles. It is good for creation vs. evolution, and so much more. Global warming vs. something else? You are covered. Homeopathy vs. physics? Done. Duons vs. the genetic code? In the bag.

Duons vs. the genetic code? What is a duon?

Good question. A duon is a DNA nucleotide that can do two roles. This perhaps makes it a rather lame nucleotide. DNA nucleotides have a lot of potential tasks they can do (eg, help encode an amino acid, be part of a protein binding site, indicate a splice site, etc) as part of their role storing information in our cells. The idea that a nucleotide might be subject to evolutionary pressure from several different tasks simultaneously is nothing new.

There is, as Emily Willingham points out at Forbes, no real “duon” controversy outside the minds of the folks that wrote the press release (and, perhaps, John Stamatoyannopoulos, if the press release quote is accurate, which I suspect it might be based on his advocacy for the ENCODE Consortium’s “junk DNA is functional” boondoggle). These researchers have provided some evidence to support the hypothesis that evolutionarily conserved codon bias (using one codon, of the several possible for an amino acid, in the genetic code more than expected by chance) is due to selection to maintain transcription factor binding sites.

This is not an unreasonable hypothesis, but it is hardly shocking, hardly requires a new term, and is hardly a controversy.