Although there might not be much of a family resemblance, the whale, hippopotamus and common cow share a common ancestor from about 60 million years ago, Japanese researchers said on Thursday.
In an article in the August 14 issue of the British publication Nature, a team of scientists led by Tokyo Institute of Technology faculty members say genetic evidence indicates the three animals belong to the same common ancestoral form, known as a monophyletic group."Our data provide evidence that whales, ruminants (grass chewers) and hippopotamuses form a monophyletic group," it said.
According to research team member Norihiro Okada, the common ancestor was probably a terrestrial herbivore.
Okada told Reuters the team looked at retroposons, a genetic element that does not change as evolution progresses, to link the three to the common ancestor.
"The team used a novel and original approach to produce these highly significant results," Okada said of the research that has given a number of species new ancestoral mothers and fathers.
The team said that about 100 million years ago, the three were in a grouping that included pigs and camels, but whales, cows and hippos derived from a separate ancestor some 60 million years ago.
"Whales are clearly related to cows and hippopotamuses, but pigs and camels have different genetic elements," Okada said.