Messaggi di Rogue Scholar

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Pubblicato in GigaBlog

GigaScience was on hand to witness plenty of lively discussion last week at the annual American Society of Human Genetics jamboree: the International Conference of Human Genetics in Montreal. As always, the meeting had a strong medical genetics presence but the rapid growth and uptake of genomics technologies in the field produced much fascinating work on display this year.

Pubblicato in Quintessence of Dust
Autore Stephen Matheson

Human evolution has been in the news quite a lot recently. New genetic data suggest that ancient humans included both Neanderthals and Denisovans, which colonized different parts of the world but subsequently interbred with so-called modern humans and left telltale traces of this history in the genomes of living humans.

Pubblicato in Quintessence of Dust
Autore Stephen Matheson

Genetic hitchhiking is thought to be an inevitable result of strong positive selection in a population. The basic idea is that if a particular gene is strongly selected for (as opposed to selected against), then the chunk of the genome that carries that gene will become very common in the population.

Pubblicato in Quintessence of Dust
Autore Stephen Matheson

The next post will discuss recent evidence for genetic hitchhiking in humans. So, what do we mean when we say that genes can hitchhike? To make sense of this phenomenon, we first need to review chromosomes and sexual reproduction. Most people know that sexual reproduction creates offspring that are genetically distinct from both of the their parents.

Pubblicato in Quintessence of Dust
Autore Stephen Matheson

Not surprisingly, Hamlet weighed in on the nature vs. nurture question, at least once. It is certainly true that "the stamp of one defect" can wreak havoc on the scale that Hamlet describes, and whether the result is a debilitating physical limitation or damage to "the pales and forts of reason," the outcome is tragic by any measure.

Pubblicato in Quintessence of Dust
Autore Stephen Matheson

In the cartoon version of evolution that is often employed by critics of the theory, a new protein (B) can arise from an ancestral version (A) by stepwise evolution only if each of the intermediates between A and B are functional in some way (or at least not harmful). This sounds reasonable enough, and it's a good starting point for basic evolutionary reasoning.

Pubblicato in Quintessence of Dust
Autore Stephen Matheson

"The Selfish Gene." "Selfish DNA." Oh, how such phrases can get people bent out of shape.  Stephen Jay Gould hated such talk (see a little book called The Panda's Thumb ), and Richard Dawkins devoted more time to answering critics of his use of the term 'selfish' than should have been necessary.

Pubblicato in Quintessence of Dust
Autore Stephen Matheson

Three weeks ago, I went to the Cornerstone Music Festival with my two oldest kids. For the second year, I was an invited speaker in the festival's excellent seminar program. This year, my two series were entitled "Alien Worlds" and "Zombies on Jeopardy" – exploring extreme biology and human nature, respectively. It was fun, if a little too hot for a day or so. At one point, I was discussing human intelligence and its genetic underpinnings.

Pubblicato in Quintessence of Dust
Autore Stephen Matheson

Defenders of intelligent design theory often dwell on the topic of "junk DNA," which has been molded into a masterpiece of folk science. The ID approach to "junk DNA" involves a fictional story about "Darwinism" discouraging its study, and a contorted and simplistic picture of a "debate" about whether "junk DNA" has "function." The fictional story is ubiquitous despite being repeatedly debunked.