Grants and Contracts Details
Description
Tiger salamanders (the Amby stoma tigrinum complex) are one of the most widely
distributed amphibian species complexes in North America (Figure IA) and lie at an important
and unique position at the intersection of research in developmental and evolutionary biology.
This diverse group contains the Axolotl (Ambystoma mexicanum), a taxon that expresses a non-
metamorphic (paedomorphic) life history phenotype. The Axoloti has been the poster child for
the study of heterochrony (Gould 1977) and has played a prominent role in developmental
laboratory research for over a century (Armstrong and Malacinski 1989; Shaffer 1993). While
paedomorphosis is common across salamanders, the A. tigrinum complex is unique in the
variability of its expression. The Axoloti is just one of many paedomorphic taxa and populations
across the geographic range of tiger salamanders exhibit a range of life histories, from obligate
metamorphosis, to facultative or obligate paedomorphosis. The evolution of a paedomorphic
morphology and ecology from a transforming terrestrial ancestor through shifts in developmental
timing is likely an adaptive response to environmental change (Wilbur and Collins 1973) and has
a strong genetic basis (Voss and Shaffer 1997; Voss et a!. 2000; Voss and Smith 2005). The
evolution of an aquatic larval life history is predicted to limit dispersal and drive population
differentiation at a faster rate than differentiation among metamorphic populations (Shaffer
1984), and may act to drive lineage divergence and speciation. As such, the A. tigrinum complex
exhibits similarities with many classic examples of adaptive radiation (e.g. African cichlid fish
and Darwin's finches) that have served as natural laboratories for the study of speciation and the
buildup of biodiversity (Seehausen 2006). There is a growing need for newly developed model
systems that bridge gaps in the Tree of Life (Abzhanov et al. 2008) and the A. tigrinum complex
can provide an excellent model amphibian system for the comparative study of biologically
important traits (e.g. metamorphosis and regeneration) and for the study of natural selection in
speciation and diversification (Routman 1993).
Status | Finished |
---|---|
Effective start/end date | 3/1/10 → 2/28/14 |
Funding
- National Science Foundation: $450,000.00
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