Evolution

These fins were made for walking

Journal name:
Nature
Volume:
478,
Page:
159
Date published:
DOI:
doi:10.1038/478159a
Published online

The first fish to emerge onto land a few hundred million years ago were equipped with pelvic-fin muscles that would eventually help their descendants to walk.

Nicholas Cole and Peter Currie at the Universities of Sydney and Monash in Australia and their co-workers charted pelvic-fin-muscle development in three extant species of bony fish, including lungfish. These creatures' ancestors gave rise to tetrapods — four-legged creatures. The authors also studied two shark species, which are more distantly related to tetrapods.

In bony fish, the pelvic-fin muscles start as extensions of body-wall muscles, just as they do in the shark species. However, only in bony fish do the cells in the developing fin muscle express a gene that is involved in hind-limb muscle development in tetrapods. The authors visualized this process by labelling cells and transplanting them from one strain of zebrafish embryo to another.

PLoS Biol. 9, e1001168 (2011)

Additional data

More Research Highlights