 Farewell, Drosophila melanogaster
Spring has arrived, and with it insects have started showing up. Much to my chagrin, it appears Bilkent houses quite a large population of milkweed bugs, and amongst all insects they're one of the very few I actively despise. Personal tastes aside, insects are quite an interesting group, being one of the most diverse (if not the most diverse) animals on the planet, and indeed quite close to humans in daily life (compare the times you've seen a fly, butterfly or beetle flying around to the times you've seen a dog or cat!) so perhaps it would be appropriate to close this year with a few interesting insects.
However, truth be told, covering all interesting insects would be difficult - I suppose even with my meager knowledge it would take at least a decade even if I wrote about them every week. You may use a blog such as Circus of the Spineless or Catalogue of Organisms to catch up on recent discoveries, or go over to relevant pages of the Tree of Life project for a more comprehensive look (just Google the names, they are all quite famous). So this week will be about a famous species of fruit fly, of which binomial designation is conveniently located in the title.
Drosophila melanogaster is a model organism, very popular in genetics research: many important genes and pathways, especially about embryonic development, were first discovered in the humble fly. As expected from a fly, it breeds fast, produces many offspring, doesn't occupy much space, is easy to feed and just small enough to note visible mutations - since research may require hundreds of the flies, you could hardly ask for a more convenient animal. But unfortunately, Drosophila melanogaster may not stay Drosophila anymore.
Every genus (in this case, Drosophila) has a type species, which defines the genus itself. If you're similar to the type species, you're inside the genus. If you're not, you're out. However, Drosophila is particularly troublesome, for the genus is huge with over a thousand described species, some of them more related to other genera than they are to other Drosophila. That calls for separation of the genus into more bite-sized chunks.
The problem arises here:
D. melanogaster is not the type species of Drosophila; quite far from it, in fact. So sooner or later, when taxonomists split the genus, our beloved fruit fly will most likely get another name. A vote was called to make D. melanogaster the type species, so that every genetics textbook written after early 1900s will not have to be corrected to avoid confusion, but the idea was refused. Soon, D. melanogaster may be no more - and that's important because smug MBG students will be able to “correct” their instructors every time it is referred to, or make up excuses like, “The report guidelines clearly asked me to research a species that does not exist!” (Just a friendly note: This won't work.) Had I been a taxonomist, I would also name a completely unrelated fruit fly as the new D. melanogaster, just to cause more confusion. I guess that's why I'm not a taxonomist - I don't even know whether the standards allow for that.
I hope I have not bored you with systematics - a field I barely understand myself. Good luck to you all on your final exams, and have a fun summer break (or a nice internship for those who share my fate!) Oh, and a small note inspired by the columns of my peers last week - should you wish to discuss mythology, biology or history, my mail address is also conveniently located up there, and I will be more than happy to provide what little I know.
BY ALPER ÖZKAN (MBG/III)
d_ozkan@ug.bilkent.edu.tr
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