Alex Palazzo managed to piss off some people with his taxonomy of biomedical disciplines. We have also learned that there are different types of physics geeks and anthropologists. (By the way, don't ever call me a geek; geeks bite the heads off of chickens. I'm a nerd.) I previously attempted to classify evolutionary biologists and named them after the important names in their particular field. It was actually a satire of the creationist ploy to call people Darwinists, so laugh. Now I'm going to further divide up the evolutionary geneticists (already a sub-set of biologists) into a bunch of other groups. Let's call it an exercise in over-splitting, which really makes me feel like a taxonomist. SNAP! Find out where you fit in below the fold.
- Classical population geneticists: These people are loyal to the early theory of Wright, Fisher, et al, and they still argue about it. They probably never stepped foot in a wet lab, or if they did it was to run an allozyme gel. They still have not caught wind of the molecular revolution. Chances are they are either emeritus, dead, or a historian/philosopher of biology. Talk to these guys if you want to know all of the theory that allows you to study evolutionary genetics.
- Molecular ecologists: These guys are really just ecologists (aka, people that like to count things) who have discovered that if they run a few PCRs they can infer population structure in their species of choice. They can easily be distinguished from other molecular population geneticists by their interest in non-model organisms and crappy molecular markers (microsatellites, mtDNA, rRNA).
- Molecular population geneticists: They have sequenced multiple alleles of some gene (probably Adh) from a single species (of Drosophila). They then ran it through the same stable of tests for selection that everyone else does. You can recognize the higher ranking members of this group by their knowledge of coalescent theory.
- Human population geneticists: They use the same data analysis techniques as the molecular population geneticists, but they don't do any of the sequencing themselves. Instead, they mine HapMap for SNPs to find out how humans migrated around the world and answer important questions like what genes make Scandinavians blonde.
- Systematicists: These guys are the taxonomists of evolutionary geneticists, only they study systematics and not taxonomy. Anyway, they basically try to find out how different species are related and they come up with phylogenies for a bunch of species. They may work with the molecular ecologists to do some phylogeography.
- Evolutionary developmental biologists: These guys study evo-devo, but calling them evo-devo-ers sounds like they're being labeled evildoers or they like guys in funny hats. They are characterized by their love of taking cis regulatory regions from one species and attaching them to a gene from another species. They are really no different from developmental biologists, except they incorporate something about evolution in the abstract of their paper.
- Data miners: Realizing that all of the genes they'll ever need have already been sequenced and deposited in the NCBI database, these guys' grant applications include requests for faster computers, bigger servers, and grad students from the computer science department. They have taken over many biology departments because they don't require any wet-lab space. Using their fancy computer programs, they compare genomes searching for highly conserved sequences, rapidly evolving sequences, and other things that some biologist told them are of interest. Chances are, they have never actually seen the organism they are studying.
- Molecular evolutionists: Every taxonomic group needs its own grab bag of species that do not fit in any other taxon. These guys may sequence genes from multiple species, but they aren't all that interested in systematics. They usually don't sequence enough individuals from a single species to be considered population geneticists. They employ many of the same analytical techniques that the data miners do, but they use their own data. They really like to compare synonymous and non-synonymous substitutions and rates of evolution along lineages.
Now it's your turn to tell me how I misclassified your discipline, or, even worse, left your important area of study off of my list. Go ahead and bitch away in the comments or add a trackback to a post on your blog. Allow me to point out, however, that I probably fall into at least half of these (paraphyletic) taxa.
Added about 10 minutes after I posted this entry: I totally forgot about all of the people that study the genetics of speciation, like Coyne and Orr. They kind of fit in with the molecular population geneticists, molecular ecologists systematicists, and classical population geneticists, but they definitely deserve their own taxon.
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Wot about the evo-devo guys? Hey? Hmm?
They're there.
Evolutionary ecologists are completely consumed with sex. Sex, sex, sex, that's all they think about. Except, it doesn't include humans. That's the real of evolutionary psychologists.
Just to prove that scientists really can't take jokes about their field*
You keep a civil tongue in your head about mtDNA. It might not be all that informative for deep phylogeny or rapid speciations but in most taxa it really has a lot to say about populations, conservation biology and pyhlogeography - especially once you get down to haplotype networks and nested clades. Just dont let the barcoders get carried away with it.
*IANAME (I am not a Molecular Ecologist - in fact I'm more like a partially differentiated stem cell - all the disease genetics/ biotech cell fates are out by most of the evo ones above are still open)
mtDNA introgresses too easily to be a good marker between species or populations.
mtDNA introgresses too easily to be a good marker between species or populations
..in the Drosophila yakuba group. Does this mean the same goes for all species?
Even if you are just yanking our chains with some of the statements about mtDNA or junk DNA, sometimes you are IMO barking up the wrong tree...
Consider humans: it has been suggested that even if recent Out-of-Africa applies for all mtDNA, there may have been some introgression of nuclear DNA. That may be a very tentative idea, but that would mean nuclear genes have introgressed more easily than mtDNA in the recent history of our species. Come to think of it, perhaps that goes the modern humans as well - at least the Y chromosome should introgress much faster between human populations than mtDNA. Not sure about other nuclear genes.
And there may be a lot of other species where "mtDNA introgresses easiest" is not true.
You go with what you have. When working with a poorly studied organism, you are limited in what markers you have available. mtDNA works, but I would also look at nuclear markers because (as you point out) they tell different stories. In an ideal world, you would sequence the entire genome of at least 30 individuals from your population(s) of interest. We, however, do not live in an ideal world.
Do any classical population geneticists exist? I see you suggest that such critters are either dead, emeritus, or historians/philosophers of biology. I'm the last, but not a classical population geneticist. But I get it. Presumably, any population geneticist --tried and true-- is probably a molecular population geneticist.
Maybe 'classical' was the wrong word, but I needed something to differentiate it from molecular popgen (classical came to mind because of classical and molecular genetics). I would say that the difference between the two is the concept of the gene/allele. In the molecular model, each nucleotide is examined for polymorphism, where as the classical model looks for allelic variation on the gene level.