Virgin births… in snakes!

Species that reproduce sexually usually need two partners to reproduce, right? Right. What I didn’t know was, females of some species (that usually reproduce sexually) have apparently been observed to be able to reproduce without a mate—rarely, and when they’re in captivity and away from potential mates.

But now, virgin births have been observed in snakes–in the wild, with males present nearby!

They captured pregnant copperhead and cottonmouth female pit-vipers from the field, where males were present.

The snakes gave birth, allowing the scientists to study the physical and genetic characteristics of the litters. […]

“That’s between 2.5 and 5% of litters produced in these populations may be resulting from parthenogenesis.

“That’s quite remarkable for something that has been considered an evolutionary novelty,” he said.

No insights yet on how and why this happens, though, or what implications it may have.

But this is fascinating, nonetheless.


☛ Rethinking Dinosaurs

The latest in paleontology:

[…] “a filamentous body covering obviously represents the plesiomorphic state for dinosaurs in general,” wrote Rauhut’s team.

Plesiomorphic is another way of saying “ancestrally typical.” In short, it was feathers all the way down.

What?! All two legged dinosaurs had feathers? What were we thinking all these years? Has this been verified?

Now they’ll have to make Jurassic Park all over again.


Of Space Worms

Found this article recently, where they wanted to check how microscopic worms would do in space. Turns out, they do fine—in fact, they actually live longer in space! Additionally:

“We identified seven genes, which were down-regulated in space and whose inactivation extended lifespan under laboratory conditions,” Szewczyk said in a press release. This basically means that seven C. elegans genes usually associated with muscle aging were suppressed when the worms were exposed to a microgravity environment. Also, it appears spaceflight suppresses the accumulation of toxic proteins that normally gets stored inside aging muscle.

They’re not sure what the biological mechanisms might be behind this phenomenon.

I wonder, though—how much of it can be simple chemistry and fluid dynamics? We know that at small enough length scales (such as those of microscopic organisms) viscosity is a much stronger agent than inertia (governed by mass, and to an extent, gravity). Often, gravitational effects are ignored when doing small scale analyses. How do things change in the actual biology when gravity is really zero, not just as an approximation?

Also from the article:

“Most of us know that muscle tends to shrink in space. These latest results suggest that this is almost certainly an adaptive response rather than a pathological one. Counter-intuitively, muscle in space may age better than on Earth. It may also be that spaceflight slows the process of aging.”

I’m not sure why this seems novel. My thought has always been that muscle atrophy in space is due to lack of use, i.e. adaptation. This is why astronauts take special care to exercise their leg muscles while at the International Space Station. The legs no longer need to support the considerable weight of the human body, and the body efficiently starts optimizing its resources!

But perhaps (and most likely) my lack of knowledge allows me to simplify a phenomenon that a physiologist would find many angles to! I’d love to know those angles though—anyone reading this who can help?