Whale evolution
Brian Tozer
>I recently read in Richard Dawkins' "Climbing Mount Improbable" that the
>ancestors of whales (and other sea animals with lungs) may have lived on
>land,
There's no "may have" about it. The ancestors of whales were
land mammals. We now have fossils of early whales with legs.
There's plenty of other evidence that the cetaceans clearly
belong within larger groups of terrestrial mammals.
>even if THEIR ancestors in turn came from the sea.
The early ancestors of land vertebrates were aquatic. Various
different groups of land vertebrates have given rise to more or
less specialized aquatic forms. Besides whales, there are/were
seals and manatees and ichthyosaurs and mosasaurs and
plesiosaurs and penguins and sea crocodiles and sea snakes and
sea turtles...
>Any arguments for or against this?
No valid arguments against it, but there's lots more you can learn
about it.
At The Waters Edge, Macroevolution and the transformation of life,
Carl Zimmer, Free Press (Simon & Schuster) ISBN 0-684-83490-1, 1998.
is a popular book on the subject.
Stuff on whale evolution
http://www.neoucom.edu/Depts/Anat/Whale.html
http://www.neoucom.edu/Depts/Anat/whaleorigins.htm
http://www.neoucom.edu/Depts/Anat/Biblio.html
http://www.angelfire.com/fl/direpuppy/CetClass.html
http://www.ucmp.berkeley.edu/mammal/cetacea/cetacean.html
http://www-personal.umich.edu/~uhen/CetRes.html
http://faculty.uca.edu/ben.waggoner/debate/whale/sld001.htm
http://www.intersurf.com/~heinrich/Basilosaurus1.html
http://www.talkorigins.org/faqs/faq-transitional/part2b.html
stuff on early origins of land vertebrates [tetrapods]
http://www.talkorigins.org/faqs/faq-transitional/part1a.html
http://www.glenn.morton.btinternet.co.uk/transit.htm
http://abcnews.go.com/sections/science/DailyNews/fishfossil0312.html
http://www.erin.utoronto.ca/~w3bio356/lectures/actinopterygians.html
http://www.geocities.com/CapeCanaveral/Hall/1636/sarcopterygii.html
<http://phylogeny.arizona.edu/tree/eukaryotes/animals/chordata/terrestrial_v
ertebrates.html>
<http://ag.arizona.edu/tree/eukaryotes/animals/chordata/terres_vert_lichen/p
hylogeny.html>
<http://phylogeny.arizona.edu/tree/eukaryotes/animals/chordata/acanthostega/
acanthostega.html>
<http://Ag.Arizona.Edu/tree/eukaryotes/animals/chordata/ichthyostega/ichthyo
stega.html>
http://www.geocities.com/CapeCanaveral/Hangar/2437/icthyo.htm
http://www.bbc.co.uk/science/horizon/missinglink_transcript.shtml
EQ
Brian Tozer
Paul Wilkins
> SQ
> > I recently read in Richard Dawkins' "Climbing Mount Improbable" that
> > the ancestors of whales (and other sea animals with lungs) may have
> > lived on land,
>
> There's no "may have" about it. The ancestors of whales were
> land mammals. We now have fossils of early whales with legs.
> There's plenty of other evidence that the cetaceans clearly
> belong within larger groups of terrestrial mammals.
There's also growing evidence that the "missing link" for human evolution is
that as apes we spent a million years or so (many many thousand years at
least) living in the sea.
Paul Wilkins
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