Hypercarnivorous Tendency As A Probable Cause of The Cat Gap
The history of carnivorous mammals is characterized by a series of rise-and-fall patterns of diversification in which declining clades are replaced by phylogenetically distinct but functionally similar clades. Over the past 50 million years, successive clades of small and large carnivorous mammals diversified and then declined to extinction. In most instances, the cause of the decline was energetic constraints and pervasive selection for larger size (Cope's rule) that lead to (hypercarnivory) dietary specialization. Hypercarnivory leads to increased vulnerability of extinction.
The nimravids were large cats that occupied this ecomorphic niche in the ecosystem until 26 Ma. It is highly likely that their hypercarnivory led to their extinction in North America. After the extinction of the nimravids there were no other feliform or Felidae species until other felids arrived from Eurasia after crossing the Bering land bridge 18.5 million years ago. During this time there was great diversity among the other carnivorous mammals in North America – both hypocarnivory and hypercarnivory species – and other hypercarnivory species existed before, during, and after the cat gap.
Read more about this topic: Cat Gap
Famous quotes containing the words tendency, probable, cat and/or gap:
“As parents it is well to be aware of the tendency to equate energetic activity with contest. Our childrens worth does not depend on their ability to trounce one another. And surely we can find ways of frolicking and being healthy and active together in some joyful, free way that is not an adversary relationship.”
—Polly Berrien Berends (20th century)
“I have very lately read the Prince of Abyssinia [Samuel Johnsons Rasselas]MI am almost equally charmed and shocked at itthe style, the sentiments are inimitablebut the subject is dreadfuland, handled as it is by Dr. Johnson, might make any young, perhaps old, person trembleO heavens! how dreadful, how terrible it is to be told by a man of his genius and knowledge, in so affectingly probable a manner, that true, real happiness is ever unattainable in this world!”
—Frances Burney (17521840)
“It doesnt matter whether a cat is black or white; as long at it can catch mice, its a good cat.”
—Chinese proverb.
“The great enemy of clear language is insincerity. When there is a gap between ones real and ones declared aims, one turns as it were instinctively to long words and exhausted idioms, like a cuttlefish squirting out ink.”
—George Orwell (19031950)