Exam 18: Evolution and the Fossil Record

Which of these is a niche that Cambrian animals occupied―that,as far as we know,their predecessors did not?

Stephen J.Gould and Niles Eldredge proposed that most morphological change happens at speciation events,and that most species show stasis (little or no morphological change)during most of their existence.This is the theory of ________.[two words]

Comparing DNA sequences from living taxa and calibrating their rates of change with at least one well-dated fossil allows scientists to create time-calibrated trees with minimum and maximum age estimates for all branch points.Such studies are called ________ [two words] studies.

The past 542 million years is collectively known as the ________ eon.

Species of fossil organisms are morphospecies,which means they are defined on the basis of ________.

An exceptionally rich fossil deposit is known as a(n)________.

The term ________ is often used for large-scale evolutionary change in general,but also more precisely for processes operating above the species level.

The famous Cambrian-era fossil deposit known as the Burgess Shale is now estimated to contain fossils of how many animal phyla?

Another common term for morphological diversity―that is,for the range of different shapes and physical features found in a taxon―is ________.

Which of the following is NOT key evidence for a large meteorite impact striking the Earth approximately 65 million years ago?