Re: NANFA-- Re: Books on the evolution and distribution of NA

unclescott (
Mon, 18 Aug 2003 23:57:18 -0500

Thank you Chris for the reference and the discussion on the role of
continental drift and speciation. I will look for Hocutt and Wiley's

Now, how about the role of glaciation and the development of North American
fishes? There are plants found in the Appalacians found usually in arctic
regions. A glance at a number of darter distribution maps suggests that they
may have accompanied the melting lines north.

Interestingly, J.H. Huber's Comparison of Old World and New World Tropical
Cyprinodonts, makes a case for speciation, isolation of relect species and
spread of new species from these relicts in the tropics, sometimes on
growing coastal planes, as sea levels drop and rise again. He sees an inland
sea in South American as responsible for the spread of many species through
out what would be some quite land locked areas today. While much of his work
traces the spread of Cyprinodonts from Gondwanaland to the western
hemisphere by way of South America and to Asia via the splintering
territiories of Madagascar, Seychelles and Indo-Asia and also the spread of
Aphanius around the Tetheys Sea basin, he notes that just the growth of
glaciers could have a significant effect upon freshwater fauna as the sea
level may have plummeted as much as 120 meters and surface temperatures
might have dropped by as much as 4 degrees C in tropical lowlands and by as
much as 10 degrees C. in the mountains. Growth and shrinkage of forests
accompanied these climatic changes, offering more and then less forest
habitats for many of the killie species.

So even in the tropics coastal planes grew. Vegetation changed and climates
were altered.

In places like North America and Europe, the spread of glaciers would have
destroyed the habitats of many populations (and species?) of fishes, altered
landscapes profoundly, pushed inhabitable areas south and bounced drainage
systems (as with the Great Lakes region) around. I imagine the size of
coastal plains must also have expanded considerably beyond what they are

Would the work above address these things? Would any other works come to
mind which especially deal with the effects of glaciation?

Thanks again,

/"Unless stated otherwise, comments made on this list do not necessarily
/ reflect the beliefs or goals of the North American Native Fishes
/ Association"
/ This is the discussion list of the North American Native Fishes Association
/ To subscribe, unsubscribe, or get help, send the word
/ subscribe, unsubscribe, or help in the body (not subject) of an email to
/ For a digest version, send the command to
/ instead.
/ For more information about NANFA, visit our web page,