Letter from Mark Cole
Biology – November 2007 – Colorado Central Magazine
Surprising statement
Ed and Martha,
I just finished reading the October issue of your great magazine. There is something unsettling about reading the October issue in September. At my age, time speeds by too quickly and this does not help.
On reading John Mattingly’s “A Farmer Far Afield” piece, I was surprised to learn that “it’s only the last 5,000 years or so in which conditions have been ideal for mammalian speciation.” Being a retired geologist with a PhD from the University of Washington with 34 years of post-graduate experience behind me, I was surprised by this statement. Mammals have flourished on planet earth for the last 65 million years, since the earth got splatted with a comet at the end of the Mesozoic Era, removing the dinosaurs and making way for our ilk. The Cenozoic Era is called the “Age of Mammals” due to vast proliferation of mammalian species.
Since the end of the ice age around 8,000 to 10,000 years ago, the number of mammalian species seems to be in decline starting with the large fauna that existed at the end of the ice age and continuing today with the spread of our species and the resultant reduction and fragmentation of habitat. I am not sure what John meant by his comment, but it does not fit with what the geological sciences have established.
Mark R. Cole
Leadville
