Well, folks, it looks like we may have a crustacean situation on our hands -- in an evolutionary move that is not at all fishy, animals keep somehow evolving into crabs. Earlier this week, the internet rekindled its fascination with carcinization, a well-documented phenomenon where animals that are definitely not crabs somehow keep evolving into crab-like beings. Or, as a famed zoologist, L. A. Borradaile, explained the concept decades ago, "one of the many attempts of Nature to evolve a crab," according to Boing Boing. So what exactly does this mean? We have crabs -- lots of them.
Now, I'm sure you have many shellfish-related questions you're itching to moll-ask - "Carly, isn't this just another instance of parallel evolution? Have you ever heard of convergent evolution? Seriously, did you even pass high school biology? Come on now!" While the answer to all of these questions is yes (although I admittedly slipped by with a B -- science is clearly not my strong suit), carcinization expands beyond the normal realm of parallel evolution, according to Popular Mechanics, meaning things are much crabbier than they probably should be. When animals are forced to fare against similar challenges, they sometimes find like ways to adapt to their circumstances, according to author Caroline Delbert. While this has been noted in many animals like marsupials, crabs are undoubtedly the evolutionary outliers, with various animals evolving into crabs at least five separate times.
"Animals can evolve separately but end up evolving toward other species, too, or even spontaneously evolve the same characteristics in totally separate groups. Birds and bats can both fly using mechanical wings," Delbert wrote. "Birds and mammals are both warmblooded, but both evolved from groups that were not. "That crabs (both "true" and ersatz) have so densely but separately evolved the same form is highly unusual, even in a world full of these examples of strong parallel and convergent evolution."
However, Twitter users seem to have no idea what to do with their newfound knowledge that apparently most evolutionary roads lead to crab-inization.
"Are there any species currently undergoing carcinization (turning into a crab)?" asked user @OccultTherapist. "God i wish i was undergoing carcinization" replied @snapper_popper, pretty much summarizing our collective feelings about this year.
"Nature skips leg day," noted user @IronProle of the phenomenon.
"Crustaceans have evolved into the shape of a crab at least 5 independent times. I do not like this," wrote user @cableknitjumper, who has since added a crab emoji next to her name. "I feel like it would be easy to start a cult based on this"
Moral of the story? I guess we're all crabby sometimes -- literally. Now, if you don't mind me, I'm going to go see if I can join this crab evolution cult. Fun times in 2020!