Intraspecific Life History Variation in the Knife-edged Livebearer Alfaro Cultratus (Cyprinodontiformes: Poeciliidae) from Costa Rica

Authors

Lacey Nay, Brigham Young University
Dr. Jerry Johnson, Brigham Young University

Keywords

intraspecific life history, knife-edged livebearer, Alfaro cultratus, Poeciliidae

College

Life Sciences

Department

Biology

Abstract

A species’ life history traits, including growth and reproduction, follow patterns of natural selection. Evolution is driven by natural selection which, in short, can be described as the ability of an organism to conform to its environment (Pianka 2000). Individuals possessing those traits that are more favorable in a specific environment tend to have higher rates of survival and reproduction, causing those traits to become more prevalent in the population. In this manner, a trait is “selected for” by nature. Life history evolution is based on the concept of trade-offs. The more energy an individual expends on growth, the less it will expend on reproduction, and vice versa. Hence, the amount of energy expended for growth versus reproduction or other traits can vary depending on selection pressures and thus be molded by natural selection (Reznick 1983).

Recommended Citation

Nay, Lacey and Johnson, Dr. Jerry (2013) "Intraspecific Life History Variation in the Knife-edged Livebearer Alfaro Cultratus (Cyprinodontiformes: Poeciliidae) from Costa Rica," Journal of Undergraduate Research: Vol. 2013: Iss. 1, Article 1095.
Available at: https://scholarsarchive.byu.edu/jur/vol2013/iss1/1095