Niles Eldredge found evidence in trilobite fossils of a pattern of evolution in which short periods of large change are mixed in with longer periods of little or no change. This pattern is called_____??
this did not help at all
Since this is not my area of expertise, I searched Google under the key words "Niles Eldredge change" to get these possible sources:
https://www.google.com/search?client=safari&rls=en&q=Niles+Eldredge+change&ie=UTF-8&oe=UTF-8
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.