The Origins, Diversity and Ecology of Cetaceans

'They say the sea is cold, but the sea contains the hottest blood of all, and the wildest, the most urgent.'
D. H. Lawrence, Whales Weep Not

A humpback whale (Megaptera novaeangliae). Photo by R. Wicklund, OAR/National Undersea Research Program (NURP); University of North Carolina at Wilmington

Cetaceans (whales, dolphins and porpoises) are a controversial group of animals, much-beloved by some, extensively hunted by others. Because of their highly derived, fish-like bodies, they have often been mistaken for fish, not least by the whale hunter Ishmael in Melville's "Moby Dick", who concluded that a whale is in fact "a spouting fish with a horizontal tail". But cetaceans are, of course, warm-blooded mammals, suckling their young and rising to the surface every now and again in order to breathe, as recognised even by Aristotle 2350 years ago. They therefore greatly testify to the mammals's stunning variability, which enabled them to colonise almost every habitat with a staggering array of shapes and sizes. In fact, whales hold many records in the animals kingdom, since the group includes both the largest animal ever to live on Earth (the blue whale) and the fastest growing one (again the great blue). Moreover, some cetaceans, especially dolphins, strike us as particularly intelligent.

How did some furry mammals evolve into these sea-going creatures? Cetaceans are the descendants of relatively small, terrestrial creatures, which lived in what is now Pakistan about 50 million years ago during the early Eocene. Although they were carnivorous, the earliest "whale" may well have resembled a small deer! These early cetaceans foraged in aquatic habitats, to which they became more and more adapted, until finally their body shape and physiology did no longer allow them to walk upon land. This website is an integrative attempt to summarise the information scientists have gathered about both fossil and extant whales. How the remarkable transformation from terrestrial to marine mammals worked, what changes it brought with it and how both ancient and modern whales have influenced and still shape their environment will be explained on the following pages.

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This website was created by Felix G. Marx, Timothy Morbey and Peter Tomiak, all University of Bristol. Please direct any questions regarding the contents of this page to Felix G. Marx.