Field of Science

Butterfly = Worm + Insect (2009, PNAS)

Shit, is it really that easy to get published? Seriously, what the fuck:

Caterpillars evolved from onychophorans by hybridogenesis
I reject the Darwinian assumption that larvae and their adults evolved from a single common ancestor. Rather I posit that, in animals that metamorphose, the basic types of larvae originated as adults of different lineages, i.e., larvae were transferred when, through hybridization, their genomes were acquired by distantly related animals. “Caterpillars,” the name for eruciforms with thoracic and abdominal legs, are larvae of lepidopterans, hymenopterans, and mecopterans (scorpionflies). Grubs and maggots, including the larvae of beetles, bees, and flies, evolved from caterpillars by loss of legs. Caterpillar larval organs are dismantled and reconstructed in the pupal phase. Such indirect developmental patterns (metamorphoses) did not originate solely by accumulation of random mutations followed by natural selection; rather they are fully consistent with my concept of evolution by hybridogenesis. Members of the phylum Onychophora (velvet worms) are proposed as the evolutionary source of caterpillars and their grub or maggot descendants. I present a molecular biological research proposal to test my thesis. By my hypothesis 2 recognizable sets of genes are detectable in the genomes of all insects with caterpillar grub- or maggot-like larvae: (i) onychophoran genes that code for proteins determining larval morphology/physiology and (ii) sequentially expressed insect genes that code for adult proteins. The genomes of insects and other animals that, by contrast, entirely lack larvae comprise recognizable sets of genes from single animal common ancestors.
This? In PNAS of all places?

Basically, worm hybridised with insect to make grub-like larval forms. Yeah. I thought "k, maybe the paper itself may have some data, or something", and even VPN'd to get it. It actually wasn't really worth it. At all. There was nothing of substance there .I expected some grotesquely misinterpreted data. It was disappointing: a few drawings pointing out the visual similarities (very robust methodology, especially for constructing phylogenetic trees. Absolutely failproof.), some rather sketchy-looking tree I was too lazy to figure out in the 2min I could spare for that paper. And discussiony-looking text. Kinda reminiscent of a certain creationist 'journal' we do not speak of in fear of death by laughter...

Via Musings of The Mad Biologist, wherein the paper is gently chewed up (could be worse). I really like the phrase 'clusterfuck of genes'. I'll be sure to steal it when necessary. Because that's really the only argument you need against this paper. And also, genes don't work like that. Really, they don't.

Come to think of it, neither does evolution. Or decent science.


  1. I totally agree this is, well, out there. Then not three days after I read about this I was stunned to see this article on natural chimeras in New Scientist:

    Wha?! No way. The Luidia sarsi story is amazing. But after thinking about all the trillions of random fertilizations that must happen in open ocean, and about monkeys and the typewriters and Shakespeare, I started to think . . . maybe so! Plants essentially have the same setup with all their pollen flying about, and natural hybrids are more common. For onychophorans and insects with internal fertilization (or at least sperm not flying through the air), not so much.

  2. this is why i hate when i see stuff written by genetic scientists about paleobiology or evolution. simple refutation of his theory, humans start out in a larval stage, we emerge from the womb in an adolescent phase and undergo a second stage metamorphosis to reach adulthood, that doesnt mean that a tadpole fucked one of my monkey ancestors, that just means that is the easiest and most effecient first stage for my species, i like how he completely ignores the simple fact that ALL land arthropods have a "soft" larval stage aside from arachnids and crustaceans, but they are of course from a different lineage. this is like saying frogs and salamanders had some fishcest going on in their early radiation which is why they have tadpoles.


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