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)

New papers from NiB contributors

White sands, New Mexico

White gypsum sands: officially an ecological opportunity

Evidently they’re not willing to toot their own horns, so I’ll do it on their behalf: Two of our contributors, Simone Des Roches and Chris Smith, have brand-new publications in print, and both papers are open access, available to anyone who wants to take a look.

Simone’s paper makes the case that the gypsum sands of White Sands, New Mexico, create an “ecological release” for lizards living there, since reduced predator density and diversity on the white dunes lets the lizards use a wider range of habitat types, and achieve higher population density.

First, we provide evidence for ecological opportunity by demonstrating reduced species richness and abundance of potential competitors and predators at White Sands relative to nearby dark soils habitats. Second, we characterize ecological release at White Sands by demonstrating density compensation in the three White Sands lizard species and expanded resource use in White Sands Sceloporus undulatus.

Chris’s paper tests the hypothesis that Joshua trees have expanded their range northward since the last glacial maximum, drawing together many different data sets to find the same signal of population expansion.

Using a database of >5000 GPS records for Joshua trees, and multi-locus DNA sequence data from the Joshua tree and four species of yucca moth, we combined paleaodistribution modeling with coalescent-based analyses of demographic and phylgeographic history. We extensively evaluated the power of our methods to infer past population size and distributional changes by evaluating the effect of different inference procedures on our results, comparing our palaeodistribution models to Pleistocene-aged packrat midden records, and simulating DNA sequence data under a variety of alternative demographic histories.