Theory of punctuated equilibrium
Punctuated equilibrium seeks to reconcile the idea of natural evolution with the missing links in the fossil record. naturalistic science assumed that the gaps in the fossil record would eventually be filled, and there would be a semi-complete record of so-called “transitional forms” between the various species. In fact, the opposite happened, and the gaps became even more pronounced. The actual fossil record indicates species seemingly appearing from nowhere, and without the long, slow, gradual changes expected by classical evolutionary theory. Punctuated equilibrium seeks to answer this problem by supposing that evolution doesn’t occur steadily, but sporadically.
In 1972, Stephen Gould and Niles Eldredge published a landmark paper on punctuated equilibrium. Their contention was that the gaps in the fossil record were best explained by gaps in evolution. That is, that most species did not change much over time, but occasionally experienced major changes in brief periods of time. “Classic” Darwinian evolution is presumed to take place very gradually, with a steady and slow change of organisms over time. Punctuated equilibrium replaces this slow change with long periods lacking any change at all, mixed with relatively short periods of rapid change.
Another way of looking at this is to say that, according to punctuated equilibrium, species are normally not evolving, and when they do evolve, it is relatively quick and dramatic. At times, this has become a source of controversy within the scientific community. Depending on whom you ask, punctuated equilibrium is either a refutation of gradual evolution, or just a specific form of it. This is one of the major disagreements over the theory – whether it replaces or enhances the classical notion of naturalistic evolution.
Despite a better agreement with available evidence, there are many scientific problems with punctuated equilibrium itself. The mechanism for punctuated equilibrium is assumed to be small groups of a particular organism separated in some way from the main population. This would accelerate the transmission of mutated genes through the population, and much more quickly produce a new species. However, multiple studies have found that inbreeding such as this produces extremely negative effects, which run counter to the idea of rapid advancement. The fossil record also calls into question the plausibility of this notion. The so-called “Cambrian Explosion,” for instance, is the sudden emergence of almost every biological type known to man, in a geological blink of an eye. This seems to contradict the idea of broad genetic stability intermixed with localized change.
Punctuated equilibrium is an attempt to reconcile available evidence with the idea of naturalistic evolution. It is, in many ways, another example of re-interpreting facts in order to fit an ideology.