Can Species Traits Predict Invasiveness or Susceptibility to Extinction?EPA Grant Number: FP916445
Title: Can Species Traits Predict Invasiveness or Susceptibility to Extinction?
Investigators: Langerhans, Brian R.
Institution: Washington University
EPA Project Officer: Cobbs-Green, Gladys M.
Project Period: January 1, 2004 through December 31, 2007
Project Amount: $105,764
RFA: STAR Graduate Fellowships (2004) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Fellowship - Zoology , Biology/Life Sciences
The objective of this research project is to understand the evolutionary contexts that generate invasive- versus extinction-prone species. Anthropogenic impacts on natural ecosystems are extensive and growing. We are only beginning to understand the ecological and evolutionary consequences of human-induced environmental changes. During the past several decades, two major concerns have emerged at the forefront of conservation biology: the loss of biodiversity and the spread of nonnative species. Most current conservation efforts regarding these problems are reactive; yet, a predictive framework designed to assess the likelihood of extinction or invasion based on species traits could greatly facilitate the conservation of threatened species and the control of invasive species.
An explicit consideration of the evolutionary history of organisms might provide a better understanding of why certain species seem “preadapted” for life in a human-modified environment, whereas others rapidly decline or disappear. As humans rapidly modify the environment, certain evolutionary strategies might be favored over others. Human-induced habitat changes frequently generate more stressful and variable environments (e.g., frequent high-level disturbance, introduction of nonnative species, and climate change). Species with evolutionary histories of coping with stressful and variable environments might be preadapted and thrive in these altered environments. Alternatively, species with evolutionary histories associated with constant environments might be at a disadvantage. I will examine this scenario within a group of livebearing fish in the genus Gambusia native to Texas, Mexico, Central America, and the Caribbean. The research will focus on the 10 species of Gambusia native to Texas, of which 2 are presumed extinct, 3 are endangered, 1 is extirpated, 1 has a restricted range, 2 are widespread, and 1 is invasive (successfully introduced on all continents but Antarctica). These species exhibit divergent evolutionary histories, including some species evolving in stenothermal springs, while others evolved in floodplain rivers. Using contemporary collections, as well as museum specimens, I will examine whether species’ traits can be used to predict invasiveness or susceptibility to extinction. I will examine specific hypotheses regarding body morphology, swimming performance, life history traits (e.g., age at maturity, number and size of offspring, and reproductive effort), evolutionary changes in phenotypes over time, and other potentially important traits available in the literature and from colleagues (e.g., physiological tolerance, diet breadth, native range size, and population genetic information). The predictive framework this research seeks to establish should lead to more effectively directed conservation and management programs.