I don’t know if it was divine intervention, or the kinship of all living things, but I tell you, Jerry, at that moment…I was a marine biologist!
There’s a debate underway between two schools of marine biologists. The received wisdom is that the brains of whales and dolphins evolved to promote cognitive advantages. The challenging hypothesis is that cetacean brains evolved to prevent heat loss due to changes in water temperatures, and their size cannot be taken as evidence of complex cognition.
Here’s the paper that started the controversy:
- Manger PR (2006) An examination of cetacean brain structure with a novel hypothesis correlating thermogenesis to the evolution of a big brain. Biol Rev 81: 293–338.
It’s governing logic is simple. Absent evidence for complex cetacean cognition, parsimony in scientific explanation – whether you call it simplicity or Occam’s razor – demands a more minimal hypothesis.
However, this is a politically and emotionally loaded issue, so it’s only to be expected that a challenge to whales’ cognitive ability will provoke a response. That’s what happened with the publication of a recent paper in PLoS Biology, just in time for the meeting next week of the International Whaling Commission. The paper has a clear, declarative title:
- Marino L, Connor RC, Fordyce RE, Herman LM, Hof PR, et al. (2007) Cetaceans Have Complex Brains for Complex Cognition. PLoS Biol 5(5)
Their’s is a two part argument, and it attacks the premise of Manger’s argument from parsimony: cetacean neuroanatomy is indeed complex enough to support cognition like that of terrestrial mammals, and cetaceans do indeed demonstrate complex cognitive behaviour.
Perhaps I’m missing something, because Manger’s attempt to exclude the possibility of complex cetacean cognition seems to be a red herring. We can have it both ways: complex cognition and temperature regulation do not need to be mutually exclusive evolutionary developments.
Note: I’ve tagged this with ‘neurolaw’ because this has implications for international law governing the whale hunt. It’s a good reminder that neurolaw isn’t just about humans.
(Hat tip to Science and Consciousness Review for mention of the PLoS article.)