Thu, May 29, 2008
Mama Fish
Posted to Current Events category
Another link to a blog with a link to a cool scienctific paper with wonderful illos.
PZ Myers at Pharyngula discusses a report on Materpiscis attenboroughi, a fossil fish from the Devonian (417 to 354 million years ago) that's so completely preserved thereis an identifiable embryonic fish complete with umbilical cord preserved inside it.
There's an artist's rendition of the fish giving birth, besides a photograph of the fossil and dsome diagrams showing what you are looking at.
And in the comments there is a neat explanation of why a retrovirus (ERV3) being present in our genome (built into our chromosomes) makes viviparity possible: the genes from the retrovirus are what keep the mother's immune system from attacking the father's genetic material in the baby. (Mostly: my Mom was RH negative and my Dad was RH positive, in the days when about all they could do was worry about babies after the first one... )
It seems that genes from retroviruses are also involved in creating the structure of the placenta.
And there is a family of asexual fishes called bdelloids that has hijacked genes from all kinds of other creatures (funguses! plants!) other bdelloids (which sounds like sex the long way around).
Biology and evolution are weird and wonderful.