Have you thought that not all the genes in your body might have the same evolutionary interests? The mouse Y chromosome has just been revealed after years of superhuman slog and turns out to be strikingly different from other non-recombining sex chromosomes in two main ways. Firstly, the mouse Y contains almost no DNA signatures of its past as a non sex chromosome. Secondly, most of it isn’t “junk”. Both these observations have shown just how much conflict within a genome can shape the evolution of entire chromosomes.
Every Friday at Nothing in Biology Makes Sense! our contributors pass around links to new scientific results, or science-y news, or videos of adorable wildlife, that they’re most likely to bring up while waiting in line for a latte.
First of all, my deepest apologies for the lateness of this post. As you may know I am a 4th year medical student and today was Match Day and I was deep in the throws of celebrating the completion of 4 years of medical education as well as learning where I will be training for the next three years in Family Medicine. So, without further adieu, your links for this week.
CJ decided to that there were too many good links and had to share several. First, as a skater herself she found an article relating to transmission of skin flora between close team mates and those competing in roller derby. Next she decided to share how the sequester is going to affect science jobs and the next few years could be difficult. But finally, a cool post on five animals that could possibly take over the world, which makes me look at spiders a little closer now.
Next, Jeremy likes the fact that new evidence from the Mars rover is favorable to the possibility of conditions that could have sustained life on the red planet.
From Noah, a video documenting several scientists as they inventory one of the worlds most biodiverse locations, the Yasuni Biosphere Reserve.
Finally, in the spirit of March Madness, from Devin comes a battle of the Mammals. “Mammal March Madness from the Mammal’s Suck blog. Although the tournament is purely fictional, the facts and natural history information given out during the extended live tweet rounds are amazing. The first rounds are already complete, but tune in for the exciting finals. Live action via twitter: @Mammals_Suck and general info via the website:”
It’s already the third day of concurrent sessions a Evolution 2012, and I’m starting to get science overload. And I still have to present my own science tomorrow! But here are some more cool results I saw Sunday and Monday:
Vera Domingues presented a study of beach mice, which have evolved lighter fur after colonizing the sandy dunes of barrier islands off the Gulf Coast. As in many other animal species, a mutation at the pigment-related locus MC1R explains a lot of the color change; Domingues showed that in the population of barrier island mice, every copy of the mutant, “light color” form of MC1R is descended from the same ancestor, and that DNA sequence near the mutation resembles sequence from the ancestral population on the mainland—which suggests that the original mutant predates the move to the barrier islands.
Richard Lankau showed how garlic mustard, an invasive weed in the United States, uses chemical warfare to out-compete native plants. Garlic mustard secretes chemicals into the soil that suppress the growth of other plants, and alters the environment for beneficial mycorrhizal fungi—and plants grown with competitors produce more chemicals. But native plants can adapt; samples of a native competitor collected from sites invaded by garlic mustard were better able to survive near the invader than plants from non-invaded sites, and were less able to benefit from mycorrhizal fungi in soil that hadn’t been exposed to garlic mustard chemistry.
Actually, that’s not really true. Biologists generally agree that predators, prey, parasites, and competitors can exert natural selection on the other species they encounter, but we’re still not sure how much those interactions matter over millions of years of evolutionary history.
On the one hand, groups of species that are engaged in tight coevolutionary relationships are also very diverse, which could mean that coevolution causes diversity. But it could be that the other way around: diversity could create coevolutionary specificity, if larger groups of closely-related species are forced into narower interactions to avoid competing with each other.
Part of the problem is that it’s hard to study a species evolving over time without interacting with any other species—how can we identify the effect of coevolution if we can’t see what happens in its absence? If only we could force some critters to evolve with and without other critters, and compare the results after many generations …
Oh, wait. That is totally possible. And the results have just been published.