Leigh Van Valen proposed the hypothesis to explain the "Law of Extinction", showing that in many populations the probability of extinction does not depend on the lifetime of this population, instead being constant over millions of years for a given population.
Leigh Van Valen proposed the hypothesis. This was to explain the "Law of Extinction". The probability of extinction does not depend on the lifetime of this population. This is in many populations. This is instead. The hypothesis to explain the "Law of Extinction" was showing this. Leigh Van Valen was being constant over millions of years for a given population.