University of Maryland Maile C. Neel  
Natural Resource Sciences & Landscape Architecture
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Biological Diversity Patterns and Reserve Design
Effects of Biased and Incomplete Data and Reserve Selection
Landscape Pattern Analysis
Evolutionary Distinctiveness of Rare Taxa
Effects of Genetic Diversity on Restoration Success
and Effects of Restoration on Genetic Diversity
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Evolutionary Distinctiveness of Rare Taxa

<i>Agalinis acuta</i> habitat The assumption of evolutionary (i.e. taxonomic, phylogenetic, or genetic) distinctiveness is a fundamental requirement for listing under the U.S. Endangered Species Act and many other state and federal conservation programs. As such, establishing the evolutionary distinctiveness of putatively rare taxa is an essential step in conservation that allows practioners to focus on entities that are most in need of conservation effort. In cases where there are questions regarding distinctiveness, detailed investigations of patterns of genotypic and phenotypic variation are warranted.

Over the last several years, questions have arisen regarding the evolutionary distinctiveness of Agalinis acuta, a federally-listed endangered species. Agalinis acuta occurs on the coastal plain in Rhode Island, Connecticut, eastern Massachusetts, on Long Island, New York, and on serpentine soils at Soldiers Delight in Maryland. Agalinis tenella occurs on the coastal plain from South Carolina to Florida and Alabama (Pennell 1935). Dr. Judith Canne-Hilliker (University of Guelph), the leading authority on Agalinis, considers A. acuta and A. tenella to be morphologically distinct (personal communication), with A. acuta having a shorter corolla, smaller seeds, shorter pedicels than A. tenella (Pennell 1935). The purpose of this research is to assess the evolutionary distinctiveness of A. acuta from other members of the genus, particularly Section Erectae (i.e. its closest relatives). <i>Agalinis acuta</i> pollinator

Preliminary molecular study of a short spacer region of the chloroplast genome failed to find differences between Agalinis acuta and Agalinis tenella, another member of section Erectae but found differences between these two species and four species from section Purpureae. Because these two species were the only two from Section Erectae included in the chloroplast DNA spacer study it is not surprising that A. tenella and A. acuta were sister taxa.

Because the lack of observed differences between A. acuta and A. tenella could have been the result of examining only a short region of a relatively slowly evolving molecule a more extensive study of chloroplast DNA variation was undertaken. In that study Neel and Cummings (2004) sequenced 6.1 kb comprising three gene regions of the chloroplast genome to examine relationships of A. acuta, A. tenella, and 13 other members of the genus Agalinis. These regions include the genes rbcL, matK and ndhF; the latter two are the most variable chloroplast gene regions sequenced so far (e.g., Johnson and Soltis 1995).

Data from these chloroplast gene regions confirmed that A. acuta and A. tenella are sister taxa and are very similar, in fact they are more similar to one another than any other pairs of taxa in the genus examined to date. Unfortunately, the sampling did not allow us to distinguish A. tenella and A. acuta.

We are now using microsatellites, additional chloroplast loci, and anonymous nuclear loci along with morphological data to quanity relationships among multiple populations of A. tenella and A. acuta in more detail within the framework of coalescence theory. We are also looking at other taxonomically confusing members of Section Erectae to clarify species boundaries in the entire group. This research is funded by the US Fish and Wildlife Service and is the focus of Jamie Pettengill's dissertation research.

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