The Emprah Protects

fuzzynecromancer asked:

why is taxonomy so yiffing weird? animals be like "we could pass for each other in a poor light but one of us is a specialized shrew and the other is a very big nematode"

bogleech answered:

basically as visually-oriented beings we judge everything based first on surface aesthetic but organisms are really more defined by the microscopic level so we keep being surprised.

I NEVER get over the fact that jellyfish, or at least some sot of cnidarian, evolved into basically a skin disease at some point.

bogleech

Myxozoa or “slime animals” are single-celled organisms that grow in the tissues of fish, causing tissue death or serious deformities in the host until they grow into a visible “plasmodium,” just like a slime mold.

They were once thought to be protozoa, but genetic sequencing proved they were cnidarian animals just like jellyfish, sea anemones and corals.

Their drifting “spore” phase even has a microscopic harpoon-like structure derived from what were the stinging cells of their ancestral jellies.

Here’s a bunch of them!

bogleech

Now what’s even MORE absurd is when genetic sequencing proved a type of parasitic “worm” to be a myxozoan.

So this “worm” is back to being a multi-celled animal that can slither around on its own and has a body symmetry completely unrelated to that of any other cnidarians.

Some sort of jellyfish over millions of years evolved back down to a single-celled form, and then one of those single-celled organisms re-evolved a more animal-like body again, completely and totally different but still genetically a cnidarian! Still equipped with the harpoon cell, too!

metagenesis

insect taxonomy in particular is under constant upheaval as we continue to investigate genetics, vestigial/reduced/internal structures, etc. to determine ancestry. insects are the most diverse body of animals on the planet so it’s a massive task to shift from morphological classification to phenological. and the results are wild.

the most accessible example i have off the top of my head: cockroaches and termites.

used to be separate orders but phenology shows that they are the same order, blattodea.

i am only in my early 30s but when i first learned insect taxonomy in grade school (i got into entomology early) termites were still in the order isoptera. the taxonomic structure changes relatively quickly and it’s constantly being worked on and revised.

it gets weirder. the order blattodea has another close relative, a sort of phenological cousin. they are so close that the two orders form a super-order of which they are the only two members.

guess what that bug is. go ahead and give it a moment’s thought. like, if you had to guess what a cockroach’s closest modern relative is, what would you say?

…

it’s the order mantodea.

the humble cockroach’s closest extant relative are the scythe-wielding man-eating murder machines, the praying mantis

right?!!? crazy! crazy awesome

bogleech

Oh yeah and this is the thing mantises and roaches evolved from, which is known as a “roachoid!”

oneirophasia

This is cool and all but how can you mention jellyfish evolving into a skin disease and not mention dogs evolving into a contagious cancer?

littlebigkaiju

I’m sorry, were you planning to elaborate on that last point right there?

oneirophasia

Only if I successfully piqued someone’s curiosity. :D Bear in mind I’m even more of an amateur enthusiast than Bogleech, so assume my explanation is only very broadly accurate.

They’re called Canine Transmissible Venereal Tumours, or CTVTs. Are you familiar with HeLa cell line, cultured from Henrietta Lack’s cervical cancer in the 1950s (without her knowledge) and repeatedly bred for a wide variety of scientific studies? The number of HeLa cells in existence today far exceeds the number of cells that were ever part of her body while she was alive. CTVTs are basically that, but naturally occurring from some poor canine 11,000 years or so ago that died with hystiocytic cancer (part of the immune system in the bone marrow). The cancer cells were (perhaps) scratched and gnawed out of the bone by other dogs scavenging its corpse, but survived by self-transplanting themselves into the skin around their claws and teeth and taking nutrients from their new host to clone themselves. A Russian veterinarian, M. A. Novinsky, proved how it spread in 1876.

It is, essentially, a unicellular, asexual, dog parasite which is transmitted by contact with an infected portion of skin. It has 14-21 fewer chromosomes than a normal dog, and has also been found transmitted to foxes and coyotes. I’ve heard its been given its own scientific name (Canis cancer), but as far as I know it’s purely unofficial.

bogleech

Oh I didn’t see you elaborated first, so I’ll just reblog this version!

Yeah you can almost think of CTVT as a single-celled, biologically immortal dog.

The same eventually turned out to be true of the dreaded Devil Facial Tumor disease that has long tormented Tasmanian devils. CTVT is at least basically harmless, clearing up on its own after a while and only surviving by just how damn contagious it is (like the common cold!) but Devil Facial Tumor can slowly cover the host’s eyes and mouth until it starves, and the confusion and discomfort can even make them more aggressive, more prone to biting, more prone to actually spreading it.

So a single long-dead devil became a parasitic illness that even inadvertently encourages its own spread, and it’s really hard not to draw “zombie” comparisons.

It also turned out even more recently that there’s a whole second lineage of it, which we now call DFT2. We’re not sure if it was triggered by DFT1 itself or something about Tasmanian Devils is just especially prone to spawning contagious tumors. Maybe the ancestor of DFT1 had simply been successful at mating and the genes for this particular mutation continue to lie dormant throughout the population?

See, that’s what the app is perfect for.

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