Research from the University of Adelaide, led by Dr Simon Tierney, has found a species of blind predatory beetle, which has evolved underground over millions of years, has genes which had previously only ever been found in species with eyes.
The beetle produces opsin proteins, which enable the brain to convert photons of light into visual pigments. The findings are odd, not just because the beetles live in an environment with no light, but because they also don’t have eyes.
The findings suggest that the genes may have evolved not through natural selection, but non-adaptive evolution or Neutral Theory. This theory suggests that some characteristics regress as a result of random neutral mutations, as opposed to selective pressure from the surrounding environment.
This study seems to support non-adaptive evolution, although it could also suggest a secondary benefit of opsin proteins, which would explain their presence in eyeless beetles.
Challenging Darwin? That’s keeping it clever.
[img source] Chris Watts – South Australian Museum
[research] Published in Royal Society Open Science.