AWC_WebBanner_A_moving_landscape

A lecture from a couple of weeks ago from visiting professor Stephen O’Brien, who was visiting New Zealand as a guest of the Allan Wilson Centre. This was part of the Allan Wilson Centre’s final series of visiting speakers.

There could be more genetic diversity among zoo animals than exists in the wild, making it important for zoos to exchange animals to keep genetic diversity.  Cheetahs have no genetic diversity.  Their descent is so closely related that skin grafts are not rejected when transplanted on unrelated animals.  Sometime about 12 000 years ago an event led to the near loss of the cheetah species.  They survived by breeding among siblings, a situation that lasted for 20 generations, fixing their genetics as permanent.

The Florida Panther of the Big Cypress Swamp came close to being inbred to the point of high probability of extinction.  Eight female pumas from a closely related species were introduced to the breeding population, allowing the panther numbers to bounce back threefold.  The inbreeding was bred out, with stronger specimens.  The survival was so successful the big cats have been sighted in Floridan parking lots.

Cats have been a successful species of mammals.  They migrated across all the world’s major landmasses.  Only Australia, New Zealand, Antarctica and the Arctic do not have native species.  There are 37 cat species.  Over 10 million years new breeds of cats emerged: house cats; Asian big cats, South American big cats, lynxes and puma, North American big cats, Asian golden cats, and the great cats.  They radiated out into new species following the rise and fall of sea levels between the continents over 10 million years.  From Asia to Africa, and to North America, down into South America, and back to Asia.  The Lions went to North America, the Pumas to South America and back again.  Did leopards follow humans out of Africa, extending as far as Russia and Java.

Tiger conservation has stalled, running over the same territory of policy again and again.  Tigers were once wider in their range and could be re-introduced to the Caspian Tiger range.  Tiger reserves still survive in the Russian Far East as the Altaic Tiger.

Once mammals were represented by little insectivores that kept out of the way of dinosaur preditors.  The KT event that drove the dinosaurs extinct left the mammals to radiate into a wide number of vacant eco-niches which they did successfully as new families of species emerged: carnivores, rodents, elephants, and others.  It takes one and a half million years to establish a new species.  It ain’t over till it’s over.

Advertisements