RT Journal Article
SR Electronic
T1 How complexity originates: The evolution of animal eyes
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 017129
DO 10.1101/017129
A1 Todd H. Oakley
A1 Daniel I. Speiser
YR 2015
UL http://biorxiv.org/content/early/2015/03/26/017129.abstract
AB Learning how complex traits like eyes originate is fundamental for understanding evolution. Here, we first sketch historical perspectives on trait origins and argue that new technologies offer key new insights. Next, we articulate four open questions about trait origins. To address them, we define a research program to break complex traits into components and study the individual evolutionary histories of those parts. By doing so, we can learn when the parts came together and perhaps understand why they stayed together. We apply the approach to five structural innovations critical for complex eyes, reviewing the history of the parts of each of those innovations. Photoreceptors evolved within animals by bricolage, recombining genes that originated far earlier. Multiple genes used in eyes today had ancestral roles in stress responses. We hypothesize that photo-stress could have increased the chance those genes were expressed together in places on animals where light was abundant.