“Among the roughly 50,000 species of extant vertebrates, we have no evidence that internal fertilisation has ever reverted to external fertilisation,” says Daniel Blackburn from Trinity College in Hartford, Connecticut, who was not involved in the study.
“Once a lineage has evolved a way for males to introduce sperm into the reproductive tract of the female, they tend to retain that mode of fertilisation.” Apparently, not, since Long’s work provides this missing evidence, Blackburn says.
dicki, Long and colleagues found both male and female genitalia that had gone unnoticed.
On the male they found bony structures that spread out on each side of the fish, with a groove that would have delivered the sperm.
It even reveals how they did it (see video, above).
“Fundamentally they couldn’t have done it in a missionary position,” says Long, pointing out that the genital structures are bony, immobile and are on the sides of the fishes.
“It is most surprising to find evidence for a loss of internal fertilisation in a fossil lineage,” he says.
So do attorneys for the shaken women, who have filed federal lawsuits.
But lawyers and civil rights advocates tell the Daily News these cavity searches are really standard policy among the Texas Department of Public Safety’s state troopers, despite their illegality — not to mention that they were conducted on the side of the road in full view of passing motorists.
Copulation was such fun, evolution discovered it again and again.
It also shows that the first jawed vertebrates were copulating.