(July 18, 2017 at 11:45 am)Mister Agenda Wrote:snowtracks Wrote:Even evolution theory recognizes that land mammals returned to the sea. Why did marine mammals go back to the sea?
Because the descendants of the species who did so were reproductively successful, due to there being ecological niches sea-going mammals were able to better exploit than fish or other sea-life could. Some of the descendants of seals may join the cetaceans as fully aquatic mammals someday; members of order Sirenia already have.
[b]"...due to there being ecological niches sea-going mammals were able to better exploit than fish or other sea-life could."
And due to their being vacant ecological niches from the extinction of the marine reptiles at the end of the Cretaceous. [/b]