Question

Paleontological studies on a lineage of bryozoans (whose fossils preserve many of their morphological characteristics) show a pattern of evolution with little or no change for long stretches of time. Occasionally, however, speciation occurred in a burst of change and diversification. This is an example of __________.

Answer 1

The pattern of evolution described is an example of punctuated equilibrium, where long periods of little or no change are followed by bursts of rapid change and diversification.

Step-by-step explanation:

The pattern of evolution described in the question is an example of punctuated equilibrium. Punctuated equilibrium is a theory in biology that suggests that species undergo long periods of little or no change, called stasis, followed by relatively short bursts of rapid change and diversification. This is in contrast to the gradual accumulation of small changes proposed by the theory of gradualism.

For example, in the case of the bryozoans mentioned in the question, paleontological studies have shown that the lineage of bryozoans exhibited little or no change for long periods of time, but occasionally, speciation occurred in a burst of change and diversification.

This pattern of punctuated equilibrium can be observed in the fossil record and is thought to be driven by environmental factors and the formation of new niches that invite rapid speciation and increased diversity.