New! Sign up for our free email newsletter.
Reference Terms
from Wikipedia, the free encyclopedia

Evolution of cetaceans

The cetaceans (whales, dolphins and porpoises) are descendants of land-living mammals, and remnants of their terrestrial origins can be found in the fact that they must breathe air from the surface; in the bones of their fins, which look like huge, jointed hands; and in the vertical movement of their spines, characteristic more of a running mammal than of the horizontal movement of fish. The question of how land animals evolved into ocean-going behemoths has been a mystery for a long time, owing to gaps in the fossil record. However, recent discoveries in Pakistan have managed to solve many of these mysteries, and it is now possible to see several stages in the transition of the cetaceans from land to sea. The most remarkable of the recent discoveries in Pakistan has been Ambulocetus, which looked like a three-metre long mammalian crocodile. Ambulocetus was clearly amphibious, as its back legs are better adapted for swimming than for walking on land, and it probably swam by undulating its back vertically, as otters, seals and whales do.

Related Stories
 


Plants & Animals News

May 15, 2026

A casual conversation between graduate students helped spark a breakthrough in aging research at Mayo Clinic. Researchers discovered that tiny synthetic DNA molecules called aptamers can selectively attach to senescent “zombie cells,” which are ...
Scientists exploring deep underwater canyons off the coast of Western Australia uncovered a hidden world packed with bizarre and elusive marine life — including signs of the legendary giant squid. By analyzing traces of DNA floating in seawater ...
Scientists have uncovered a hidden mathematical secret inside the leaves of the Chinese money plant: a naturally occurring geometric pattern known as a Voronoi diagram, something typically associated with city planning, computer science, and network ...
Scientists at UBC Okanagan have uncovered how plants produce mitraphylline, a rare natural compound with promising anti cancer potential. The team identified two enzymes that work together to build the molecule’s unusual twisted structure, solving ...
Researchers created a special kind of algae that can grab microscopic plastic pollution out of water almost like a magnet. The algae produce limonene, an orange-scented oil that helps them bind to water-repelling microplastics, forming ...
Scientists at the University of Rochester pulled off a remarkable experiment: they transferred a longevity-related gene from the famously long-lived naked mole rat into mice, and the mice ended up healthier and lived longer. The special gene boosts ...
Scientists studying axolotls, zebrafish, and mice have uncovered a shared set of genes that may one day help humans regrow lost limbs. By identifying powerful “SP genes” involved in regeneration, ...
Scientists have uncovered a surprising way to influence the bacteria living in our mouths — not by killing them, but by interrupting how they “talk” to each other. Researchers found that dental ...
Beneath the beauty of coral reefs lies a hidden universe of microbes unlike anything scientists expected. Each coral species supports its own specialized microbial partners, many of which have never ...
A little-known tree from Brazil’s Atlantic Forest may hold a surprising weapon against COVID-19. Researchers discovered that compounds called galloylquinic acids, extracted from its leaves, can attack SARS-CoV-2 on multiple fronts—blocking the ...
Long before humans spread across the globe, a deadly disease may have quietly shaped where our ancestors lived—and even how we evolved. New research reveals that malaria didn’t just threaten early human survival; it actively pushed populations ...
Crabs’ famous sideways walk may trace back to a single evolutionary moment 200 million years ago. Researchers found that most modern crabs inherited this trait from one ancestor—and never looked back. The movement likely gave them an edge, ...

Latest Headlines

updated 12:56 pm ET