Or, “way more than you wanted to know about primates”

TIL:

1. When I first was exposed to taxonomy stuff (7th grade), monkeys had tails (and were the New World things) and apes didn’t (and were the Old World ones). They were sort of sister groups under the land of Primate, which also included humans (but we were, of course, special). All the lemurs and so forth were “prosimians” and/or “lesser primates” (if I remember correctly).
   
   We don’t believe this anymore (Advances in SCIENCE!)
   
2. Now we believe that the land of Primate has is divided into:
   • Strepsirrhini — lemurs, galagos, and lorisids (Slow Loris – SQUEE!
   • Haplorhines — basically tarsiers (and I haven’t figured out why they got their own category), and
   • Simians — monkeys and “apes”². The Simians are divided into two parvorders (“parvorder” is another thing that didn’t exist in the 7th grade) — see footnotes …the names of the two suborders are kinda cool!
     • Platyrrhini³ (New World monkeys) and
     • Catarrhini⁴, which consists of the family Cercopithecidae (Old World monkeys in the stricter sense) and the superfamily Hominoidea (apes – including humans!⁵).
       
3. All Catarrhini³ (including humans) lost the enzyme α-Galactosidase **that is present in all other mammal lineages** sometime after the split from platyrrhini.
   
   The wikipedia page about α-Galactosidase was correct in its self-assessment:
   “This article may be too technical for most readers to understand.”
   
   If someone can explain what exactly all the Catarrhines can’t do because of the missing enzyme, I’d be delighted (my gut says it’s why we don’t eat bamboo or trees and has something to do with cellulose being Not Food, but who knows?)
   
   (But wait — one more impressive factoid!)
   
4. Somehow (somewhere) in these many wikipedia pages that I was reading I ran across the fact that one of the suborders of primates (Haplorrhini, which includes humans) has a non-functional version of L-Gulonolactone oxidase (GULO), which is an enzyme that somehow helps critters enzymatically synthesize Vitamin C. Turns out that in a parallel fashion some bats and all guinea pigs also lost their functioning GULO.
   
   This is the bit where I internally tied together some previously unconnected info and was delighted with myself.
   
   Turning to Adrian, I said: “Weird thing: guinea pigs also have the a non-functional version of the GULO enzyme that humans do. I wonder if guinea pigs get scurvy?”
   
   Turning quickly to the Googs, I typed “do guinea get s…” and before even finishing my query I got my results: YES! Guinea pigs can and do get scurvy. I was delighted by this (not that guinea pigs can get scurvy, that’s sad, but that I remembered that Vit C deficiency causes scurvy, etc. etc.)
   
   Break from the ever-evolving (see what I did there?) world of taxonomy for some Slow Loris action:

¹ It’s not the reading. I like reading. But I like knowing even more, so I end up re-reading and flipping back between eleventy-three open tabs trying to cross-reference things to ensure I really understand them. Then I feel the need to share all my new, nifty info. Adrian is Deep In YouTube land with headphones on, so you’re the Lucky Winner of this newly won knowledge.
² Platyrrhini = flat noses… nose holes (ok, nostrils) point out to the sides
³ from Ancient Greek katà = down; rhin = nose, Catarrhini = down nosed monkeys = nose holes point down.
⁴ Other distinguishing characteristics include that Catarrhines have flat nails and never have prehensile tails (tho they can have regular, non-prehensile tails, for, you know, decorative purposes). Also something about tubular ear bones and dentition.
⁵ But (according to Wikipedia: “Apes (collectively Hominoidea /hɒmɪˈnɔɪdi.ə/) are a clade of Old World simians native to sub-Saharan Africa and Southeast Asia (though they were more widespread in Africa, most of Asia, and Europe in prehistory), which together with its sister group Cercopithecidae form the catarrhine clade, cladistically making them monkeys.”)

My interpretation of this (which may very well be wrong, and if someone knows for sure, please correct me) is that on the basis of shared characteristics, apes are “monkeys” (/simians); however, in real world usage people still tend to say that Apes and Monkeys aren’t the same (and, well, people are Very Very Different, of course. ;-)

tl;dr:

• People are monkeys
• Everything I thought I knew about taxonomy is wrong
• Wikipedia can be a Dangerous Place if it’s getting late and you’ve gotten curious
• Guinea pigs (and some bats) can also get scurvy