The Life Sciences building at the University of Idaho. Photo by jby.
Over at Nothing in Biology Makes Sense! I’m confronting my discovery that the University of Idaho, where I received my Ph.D., has hired an outspoken proponent of young-Earth creationism to teach its introductory microbiology course this semester:
I can, at least in principle, imagine a creationist professor who taught the contents of a microbiology curriculum, complete with the common descent of life on Earth, and never breathed a word of his personal beliefs in the classroom. Could Gordon Wilson—of all people—be that “gold-star” creationist?
I decided the only way to answer that question was to ask Gordon Wilson.
Wilson, you may recall, appeared on D&T before, many moons ago. To find out what he had to say for himself, go read the whole thing.◼
Welcome, pollinators! But, um, everyone else can just stay out, okay? Photo by Yeoh Thean Kheng.
Over at Nothing in Biology Makes Sense!, I’ve written about a neat study of the tropical vine Dalechampia scandens, which has to solve an evolutionary puzzle that confronts most flowering plants:
But there’s a downside to making a big, showy display to attract pollinators—you might also attract visitors who have less helpful intentions than gathering up some pollen and moving on to the next flower. Showy flowers might attract animals that steal the rewards offered to pollinators—or they might attract animals that eat the flowers themselves, or the developing seeds created by pollination.
To see how a team of biologists directly measured this evolutionary compromise (spoiler: it involves counting pollen grains with a hand lens) go read the whole thing.◼
Over at Nothing in Biology Makes Sense!, Sarah Hird introduces us to the concept of the holobiont and its hologenome:
Most evolutionary biologists probably consider the individual as the fundamental unit of natural selection. We think about the genes of one mother or one father being passed on to one descendant. But is this view too constrained? The “hologenome” is all the genomes that belong to the “holobiont” – an organism and all its microbes.
Would natural selection be better understood as acting on organisms together with all the microbes they host? Go read the whole thing and see what you think.◼
Over at Nothing in Biology Makes Sense, guest contributor Jessica Oswald explains how a new fossil of a bird that lived 52 million years ago helps explain the origins of some of nature’s greatest aerial acrobats:
Swifts are able to reach the highest speeds during level flight (Chantler 1999) and hummingbirds are well known for their hovering abilities and their sideways and backward flight. Swifts and hummingbirds, while sharing the same wing bone characteristics, have different lengths of flight feathers, resulting in different wing shapes across the group, which allows them to perform their different aerial feats. Hummingbirds have shorter wings relative to their body size compared to swifts, resulting in their hovering abilities. These different wing shapes are well suited for their modern functions, but we have almost no fossils from this group, so we don’t know how the wing shapes diverged, or anything about the ecology of ancient species in this lineage.
To learn what the common ancestor of swifts and hummingbirds (or, rather, one of its early descendants) looked like, go read the whole thing.◼
This week at Nothing in Biology Makes Sense! I’m discussing a nifty new study that suggests interacting species can sometimes tolerate stressful environments by helping each other out:
This was the perspective of Peter Kropotkin, a Russian prince and political anarchist who studied the wildlife of Siberia while working as an agent of the Czar’s government. In the harsh conditions of the Siberian winter, Kropotkin reported finding not a bitter struggle over scarce resources, but what he called “Mutual Aid” among species, as well as in the human settlements that managed to eke out a living.
Something like what Kropotkin described is documented in a new paper by Elizabeth Pringle and colleagues. Examining a protection mutualism between ants and the tropical Central American tree Cordia alliodora, Pringle et al. found that drier, more stressful environments supported more investment in the mutualism.
To learn how ants can help a tree deal with drier climates—no, it doesn’t involve little tiny bucket brigades—you’ll have to go read the whole thing.◼
This week at Nothing in Biology Makes Sense, there’s a post from yours truly about a curious case of developmental flexibility in some Australian lizards. It seems that rainbow skinks (Carlia longipes) develop bigger bodies and longer legs if they’re incubated in cooler nests—and those developmental changes provide an advantage in the rocky habitats where nest temperatures are typically cooler:
Life is risky for a newly hatched lizard. You have to make your way in a habitat you’ve never seen before, full of all sorts of larger animals that think you’d make a decent snack, if maybe not a full meal. Wouldn’t it be nice if you could’ve been preparing for the conditions you’ll meet out there even before you crack through that shell?
Well, for one species of skinks, it looks like this may be exactly what happens. A recent paper in The American Naturalist makes the case that rainbow skinks (Carlia longipes) develop in their eggs to match the habitat conditions around their nest—based on the temperature of the nest.
This is a classic case of phenotypic plasticity, in which development responds to the environment to provide a better fit—but in Carlia longipes, plasticity goes beyond growing longer legs. To find out what’s up with these skinks, go read the whole thing.◼
Over at Nothing in Biology Makes Sense!, Sarah Hird describes a new study of what happens to the microbial community of the human penis when you make a … let’s say a certain change to its environment?
They begin by sampling the penile microbiota of 156 uncircumcised men. Approximately half of the men are then circumcised and all subjects are resampled after one year (presumably enough time that behavior is unaffected by the procedure).
Yeah, it’s maybe not surprising that circumcision would change what kinds of bacteria hang out in the region formerly covered by the foreskin. But apparently that change may contribute to the reduced rate of HIV transmission associated with circumcision. To find out how, go read the whole thing.◼
Over at Nothing in Biology Makes Sense! Noah Reid takes a look at a new study of the recent evolutionary history of pigs:
Domestic pigs are in the family Suidae, which includes the babirusas, warthogs, the endangered pygmy hog (whose generic name is, Porcula, seems a likely candidate for America’s next tragic children’s cereal) and the domestic pig’s close relatives in the genus Sus. Depending on where you draw the lines, there are around 7 species in Sus. With the exception of the wild boar (Sus scrofa) their natural ranges are restricted to Southeast Asia west of Wallace’s Line.
Because domestic pigs are prone to going feral and getting, um, re-familiarized with their wild relatives, unravelling their history using genetic data is tricky business. To see what the new study found, go read the whole thing.◼
This week at Nothing in Biology Makes Sense! Noah Reid takes a look at a study that attempts to disentangle the effects of reproductive isolation between species and the rate at which new species are formed. Why would you want to do that? So you can tell whether the former causes the latter!
RI [reproductive isolation] is often thought to be important in diversification because some theory predicts that even low levels of intermating between populations can prevent divergence from occurring and because hybridization between divergent populations can cause them to homogenize, or cause one population to become extinct. If these factors commonly prevent speciation or cause incipient species to go extinct, one might expect a positive correlation between the rate of evolution of RI and DR [species diversification]. This paper is the first test of this prediction.
But, of course, a lot of biologists would say that the evolution of reproductive isolation is the evolution of a new species … so things get a bit complicated. Go read the whole thing, and see what you think.◼
Over at Nothing in Biology Makes Sense!, I’ve written about a new study that tries to disentangle conflicting sources of natural selection to determine whether big herbivores like antelope, zebras, and ostriches have evolved to run because they’re always running away from predators.
An antelope’s frame is under more demands than evading cheetahs—it also needs to travel long distances to follow food availability with the shifting rainy season. In fact, the North American fossil record suggests that big herbivores on that continent evolved long legs for distance running millions of years before there were predators able to chase after them. And then again, not all predators run their prey down; lions, for instance, prefer to pounce from ambush.
To find out whether gazelles are running for their lives, or running for dinner, go read the whole thing.◼