The desperate gene.
Gombe Stream is a 52-mile national park in Tanzania where Jane Goodall famously studies chimpanzees. Other wildlife lives in the park too, and the lot are an island surrounded by urban Tanzania.
From Alan Weisman's The World Without Us:
Red-tailed monkeys have small black faces, white-spotted noses, white cheeks, and vivid chestnut tails. Blue monkeys have bluish coats and triangular, nearly naked faces, with impressive jutting eyebrows. With different coloring, body size and vocalizations, no one would confuse blue and red-tailed monkeys in the field. Yet in Gombe they now apparently mistake one another, because they have begun to interbreed. So far, Detwiler has confirmed that although the two species have different numbers of chromosomes, at least some of the offspring of these liaisons-whether between blue males and red-tailed females or vice versa-are fertile.
Faced with a common shortage of mates, the two species are disappearing into each other.
From Alan Weisman's The World Without Us:
Red-tailed monkeys have small black faces, white-spotted noses, white cheeks, and vivid chestnut tails. Blue monkeys have bluish coats and triangular, nearly naked faces, with impressive jutting eyebrows. With different coloring, body size and vocalizations, no one would confuse blue and red-tailed monkeys in the field. Yet in Gombe they now apparently mistake one another, because they have begun to interbreed. So far, Detwiler has confirmed that although the two species have different numbers of chromosomes, at least some of the offspring of these liaisons-whether between blue males and red-tailed females or vice versa-are fertile.
Faced with a common shortage of mates, the two species are disappearing into each other.