Hippos & Whales

Susan Brassfield (susan-brassfield@ou.edu)
Tue, 31 Aug 1999 16:35:09 -0600

This has a bearing on what we have been talking about recently. I thought a
few of you might find it interesting.

Monday August 30 5:16 PM ET

Gene Study Links Whales and Hippos

WASHINGTON (AP) - One has no legs and swims in the ocean, and the other has
four legs and lives in rivers, but a genetic study shows that the whale and
the hippo are close relatives in evolutionary history.

The study, by researchers at the Tokyo Institute of Technology in Japan and
Pennsylvania State University at University Park, Pa., compared gene sequences
from the minke whale, the sperm whale and the hippopotamus. It found the
diverse animals share a sequence of genes inherited from an ancient common

A report of the study appears Tuesday in the Proceedings of the National
of Sciences.

The study found that the camel, pig, giraffe, sheep and cow share some gene
sequences with the whale and hippo, indicating that far back in time all had a
common ancestor, according to evolution theory. The animals diverged
A gene sequence found only in whales and the hippo show that they share a
common ancestor that was not part of the evolutionary history of the other

Until 1985, it was generally thought that pigs were more closely related to
Other genetic studies since have suggested the whale-hippo link. The new study,
researchers say, confirms that the hippo is the closest living relative to
the whale.

The genetic analysis was conducted by Masato Nikaido and Norihiro Okada of the
Tokyo Institute and by Alejandro Rooney of Penn State.

It has long been believed that the whale's ancient ancestor was a land
animal. It is
thought that a lineage leading to the modern whale returned to the sea and
evolved into a group of marine mammals called cetacean. Along the way, hind
legs were lost, and forelegs were replaced by flippers.

David Hillis of the University of Texas, in a PNAS commentary, said whales and
hippos share several adaptations, including the lack of hair and
oil-producing skin
glands, and the ability to communicate and to nurse offspring under water.


"Life itself is the proper binge."
--Julia Child