Jump to main content or area navigation.

Contact Us

Extramural Research

Grantee Research Project Results

Grantee Research Project Results

Assessing the Impacts of Human-Induced Habitat Alterations on Natural Populations: Testing Alternative Hypotheses for Morphological Shifts in a Caribbean Lizard

EPA Grant Number: FP916397
Title: Assessing the Impacts of Human-Induced Habitat Alterations on Natural Populations: Testing Alternative Hypotheses for Morphological Shifts in a Caribbean Lizard
Investigators: Marnocha, Erin L.
Institution: University of California - Los Angeles
EPA Project Officer: Jones, Brandon
Project Period: January 1, 2004 through December 31, 2004
Project Amount: $100,456
RFA: STAR Graduate Fellowships (2004)
Research Category: Fellowship - Terrestrial Ecology and Ecosystems , Academic Fellowships , Ecological Indicators/Assessment/Restoration



The objective of my research is to understand how human induced habitat alteration in the Bahamas has affected populations of Brown anoles, Anolis sagrei. A. sagrei in the Bahamas are abundant in both natural and disturbed habitats. Natural habitat is composed of dense stands of vegetation whereas disturbed habitat is characterized by the lack of natural vegetation and the presence of human structures such as buildings and sidewalks. Preliminary data demonstrate that A. sagrei in natural and disturbed habitats differ significantly in both size and shape. My research aims to assess the role of natural selection as well as the role of the environment in driving the observed intraspecific morphological variation in A. sagrei.


I intend to utilize a range of methodological approaches to understand the underlying mechanisms responsible for the intraspecific morphological variation. Survivorship data obtained from a series of mark-recapture experiments will be used to estimate the strength and form of selection potentially driving the morphological differences between A. sagrei in natural and disturbed habitats. The heritability of any traits under selection will be determined from parent-offspring regression of dames, sires, and their progeny raised in the laboratory. I also will assess several ecological attributes of each habitat that potentially influence lizard morphology, such as thermal characteristics, food availability, and predator abundance. Ecological data obtained in the field will be used to design laboratory experiments with the goal of determining the relative importance of genetics and environmental factors in determining growth patterns and morphology in A. sagrei.

Supplemental Keywords:

fellowship, habitat alteration, disturbed habitat, Brown anoles, Anolis sagrei, natural selection, morphological variation,, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Habitat, Ecological Risk Assessment, Ecology and Ecosystems, habitat use, carribean lizard, animal responses, land use effects, community composition, habitat loss, habitat disturbance, morphological shifts, ecological consequences, anthropogenic stressors, habitat fragmentation, conservation biology

Relevant Websites:

2004 STAR Graduate Fellowship Conference Poster (PDF, 1p., 106KB, about PDF)

Top of Page

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

Jump to main content.