“The cause of these great extinctions, the most extensive in the seventy-million-year record for mammals, is a mystery. The two prevailing guesses, climatic environmental pressure or the destruction caused by human immigration in these regions, are at a stalemate. Nearly… — Stephen J. O'Brien Copy Share Image
“Left alone, the Florida panther would be remembered as a textbook exercise on how to go extinct while your abundant and vociferous advocates argue… — Stephen J. O'Brien Copy Share
“The evidence of cheetah genetic monotony would only grow. Bob Wayne, a talented postdoctoral fellow in our lab, examined cranial measurements and the bilateral… — Stephen J. O'Brien Copy Share
“Field biologists studying large and charismatic animals wanted to know if their own species had genetic problems. I listened carefully to stories of koalas… — Stephen J. O'Brien Copy Share
“Within a few months Mitch Bush, head veterinarian at the National Zoo, and David Wildt, a young reproductive physiologist working as a postdoctoral fellow… — Stephen J. O'Brien Copy Share
“Over the past sixty years a rather impressive assembly of respectable taxonomists and evolutionary biologists have tried to unseat the biological species concept for… — Stephen J. O'Brien Copy Share
“Taxonomy, also called systematics, is the science-based hierarchical classification of the world's species. The area had traditionally been an obscure academic discipline dominated by… — Stephen J. O'Brien Copy Share
“It seems a shame that less than 1 percent of all the species that ever lived survive today and that only about 5 percent… — Stephen J. O'Brien Copy Share
“[Giant northern elephant seals] were presumed extinct as late as 1912 when a group of eight seals was spotted on Guadalupe Island in the… — Stephen J. O'Brien Copy Share
“The cause of these great extinctions, the most extensive in the seventy-million-year record for mammals, is a mystery. The two prevailing guesses, climatic environmental… — Stephen J. O'Brien Copy Share
