And Then Evolution Said, "Hold My Beer"

[Paleophyte]

This is a thread for those WTF organisms that just shouldn't exist in any sane universe, but evolution produced while drunk, bored, or tripping balls.

Self-Decapitation as a Survival Strategy

Yup, you read that right. A few species of sea slug practice "extreme autotomy", where their heads can shed their entire body. More modest examples of autotomy occur in lizards, starfish, and lobsters that can shed less significant body parts to avoid predators. But Elysia manages to shed its entire body, not to escape predation, the process is too slow for that, but possibly to ditch parasites. The severed head simply crawls off and regenerates the detached body. Normally, that would be a challenge for an organism, not having any way to eat while it tries to rebuild, but Elysia practices kleptoplasty, the fine art of stealing cellular components from the algae that it consumes. It eats algae and steals their chloroplasts, keeping them alive to help nourish it via photosynthesis. So, when the head detaches, it can literally take the off-grid solar option for the few weeks that it takes for its guts to regenerate. One of the creepier aspects is that the headless body continues to wander around for days and will even respond to stimuli until it finally succumbs to starvation. I wish that I'd seen this one in time for Halloween.

Here's a general article on it in Smithsonian Magazine.

And the original research in Current Biology.

[Gawdzilla Sama]

I shed 160 pounds of ugly fat. Haven't heard from her since.

[Paleophyte]

Enter xenoparity.

The standard scientific dogma is that a species is a population of organisms that can reproduce amongst themselves but not with members of other species. There are some notable exceptions, but in most cases, organisms don't produce viable offspring with interspecies reproduction. If they did, the gene pools would merge and you'd be left with a single species.

Or that's what we thought until researchers took a close look at some ants in Spain. The Iberian harvester ant (Messor ibericus) uses this one cool trick that lets it produce stronger workers. It hybridizes with its close relative, Messor structor. This produces more vigorous workers, and since all ant workers are sterile anyway it doesn't matter that the hybrids can't reproduce. The colony gets stronger workers and the queens get twice as much action.

But what's a M. ibericus queen to do if there are no lonely M. structor males looking to hook up tonight? Well, fear not. The queens simply clone themselves a bunch of M. structor males. They produce a specialized egg that has no nuclear material. It's then fertilized by the M. structor sperm that she carries, producing haploid M. structor males. That lets the colony continue on hundreds of miles from the nearest M. structor colonies.

So is that one species or two? Send in the clones.