#Evol2012: Puffin poop and predation pressures


A final few propitious presentations from the Evolution meetings in Ottawa:

Kirsten Bowser is running puffin faeces through next-generation sequencing to identify what the adorable seabirds eat—and she’s already found some prey species that wouldn’t be easily identified just by watching what puffins bring back to their nests.

Brian Counterman showed that hybridization between subspecies of the South American butterlfy Heliconius erato with different wing patterns can transfer wing patterning between subspecies—mostly by transferring a single chunk of DNA that doesn’t code for any protein, but performs a regulatory function. What’s more, the same region is being moved between multiple pairs of hybridizing H. erato subspecies.

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#Evol2012: Competitive flowers, bleached lizards, burrowing mice, and robust invaders

Iochroma fuchsioides. Photo via Wikimedia Commons.

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.

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#Evol2012: Inversions and spruces and tethered snails

Some highlights from the first day of concurrent sessions in the Ottawa Convention Centre, on Saturday the 7th:

Mohamed Noor described the importance of chromosomal inversions—literally, chunks of DNA code that have been flipped end-to-end within the chromosome—in reproductive isolation between two species of Drosophila fruit flies. Inversions have the interesting effect of preventing recombination from breaking up groups of genes within the inversion; but some recombination is still possible, if very rare, and it should create predictable patterns of genetic divergence across the inverted region.

Most of the major phenotypic differences between Drosophila pseudoobscura and D. persimilis map to three regions that are inverted in one species relative to the other—Noor presented work from his lab that finds very fine-scale differences in genetic differentiation across the inversions, consistent with predicted variation in recombination. In a much-retweeted line, Noor pointed out that it’s possible to think of species as “groups of alleles in long-term association.” Chromosomal inversions being one way to help maintain those associations, plainly.

Sitka Spruce - Wild-Pacific-Trail-20100606-IMG_1148.jpg

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Friday coffee break

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.

Simone is in the field at beautiful White Sands, New Mexico, and blogging about it.

The setting is White Sands, NM – an island of gypsum dunes slowly transforming and shifting through the Chihuahuan Desert. The protagonists are three species of small white lizards inhabiting these dunes. The story is recent and rapid evolution: changing ecology, natural selection, and speciation. Our attempt, as field biologists, is to tell that story.

Noah points us to NASA’s satellite images of the Columbia Glacier in southeastern Alaska, which, like a lot of glaciers these days, is getting smaller.

In 1986, the glacier’s terminus was just a few kilometers north of Heather Island. By 2011, it had retreated more than 20 kilometers (12 miles) to the north, moving past Terentiev Lake and Great Nunatak Peak. As the glacier has retreated, it has also thinned substantially, as shown by the expansion of brown bedrock areas. Rings of freshly exposed rock, known as trimlines, are prominent in the later image. Since the 1980s, the glacier has lost about half of its total thickness and volume.

Devin suggests a recent editorial in Science on the need to connect people with graduate-level science expertise to high school science education.

At any one time, there are thousands of U.S. Graduate Students with strong Science expertise and an interest in education who would be more than qualified to stem the critical shortage of secondary chemistry, physics, earth sciences, and biology teachers, but who will most likely never set foot in a high-school (precollege) classroom.

Sarah points out that the BBC has a treasure trove of video on adaptations for defense against predators. (The one titled “snake in the grass” is especially great. —Jeremy)