Honors College

Document Type

Honors Thesis




Brian McGill

Committee Members

Jacquelyn Gill, Mark Haggerty, Alessandro Mereghetti, Paul Rawson

Graduation Year

May 2021

Publication Date

Spring 5-2021


A good understanding of the past can shed light on the patterns observed and mechanisms at work in the present day.As the climate continues to change in the present, we can look to the past to help determine how organisms might react to large scale habitat shifts. The Great American Biotic Interchange (GABI) is a past biotic interchange that can offer a unique perspective on dispersal.It occurred roughly 3 million years ago (MYA) when the continents of North and South America were first joined by the formation of the Isthmus of Panama. By looking at the body masses and diet compositions of the organisms living on these continents at this time we can find some patterns determining which organisms are more likely to invade and which are not. This was done by collecting data from Carrillo et al. (2020), The Paleobiology Database, and PHYLACINE_1.2, and running various t-tests and regression analyses. Invader masses were found to be higher at the start of the GABI and decreased as time went on. Also, invader masses tended to be higher than non-invaders. Analyses on diet data support observations in the literature that North American carnivores were highly successful in South America.

Included in

Biology Commons