Paleomammologist George Gaylord Simpson

"The known specimens of Mesozoic mammals are among the most precious and important remains of extinct life which have yet been discovered. They are the sole direct evidence of the fundamental first two-thirds of evolution of the Class Mammalia, which is now dominant on the earth and to which we ourselves belong. This importance has long been rather vaguely recognized, but it can hardly be said to have been properly evaluated. The Mesozoic forms are usually briefly dismissed as being rare, fragmentary, and poorly understood - accusations which are true, but not in the accepted degree."

Introduction to SIMPSON, G.G. (1929): "American Mesozoic mammals".

George Gaylord Simpson (1902-1984) was born in Chicago in a religious family, but already in childhood he rejected religion as childish behaviour and displayed an intense interest in facts.
At age 16 he entered University to become a writer, but in the second year he enrolled in a geology course, and following the advice of his instructor Arthur Tieje he changed to Yale University as the best place to study geology and palaeontology. Here, in the basement of the Peabody Museum, he discovered a large collection of yet not studied Mesozoic mammals, but his advisor, Richard Swann Lull, despite the enthusiasm and abilities displayed by Simpson, mistrusted him: "those fossils are much too important very delicate and highly significant for a young graduate student."
Only in the following year, after a successful field season in Texas and New Mexico, where Simpson discovered fossils of Pliocene and Miocene mammals, Lull permitted Simpson to approach the valuable fossils (and despite one initial accident, when Simpson stumbled over one of the first fossils to be recovered, breaking it).

After his graduation from Yale, Simpson went to the Natural History Museum in London, where he continued his studies on the bones of early mammals, comparing the American to the European species - the results were important monographs of the evolutionary relationships of the various groups.

Fig.2. Figure of the dentition of various American Mesozoic mammals, published in SIMPSON, G.G. (1929): "American Mesozoic mammals", one book in which he summarize the results of his intense studies on fossils from America and Europe.

In 1927 back to America, he joined the American Museum as assistant curator of fossil vertebrates, position inherited from his former mentor.
Simpson continued his work on the taxonomy of mammals, but begun also to introduce theoretical methods and concepts in palaeontology.
In the years 1942 to 1944 he fought in World War II and was sent to Nord Africa, Sicily and Italy, obtaining the rank of major.
After the war he returned to the United States, becoming professor of vertebrate palaeontology at Columbia University and later curator for the Museum of Comparative Zoology at Harvard University.

Simpson popularized palaeontology and evolution with various books for the general public, but also contributed to a general synthesis of evolution by proposing that small genetic variations in populations are in fact the breach on which natural selection can act, and that therefore the observed chance in the fossil record is explainable by evolution. It is again the irony of history that George Gaylord Simpson, like Darwin or Gould, is apparently one of the most quote-mined evolutionists by creationist in the Internet…

Online Resources:

RYAN, M.J. (16.06.2011): Born This Day: George Gaylord Simpson. (Accessed 16.06.2011)
Cover picture from LAPORTE, L.F. (): George Gaylord Simpson - Paleontologist & Evolutionist 1902-1984. (Accessed 16.06.2011)
LAPORTE, L.F. (2004): Rock Stars George Gaylord Simpson (1902-1984). GSA TODAY September 2004: 16-17