Ph.D.Washington University, St. Louis
My research interests focus on basic evolutionary questions, and aspects of the population genetics of rare species and/or isolated populations. Much of my research addresses three types of questions:
(1) What happens when species come together and hybridization occurs? For example, what is happening to the narrow soil endemic Ceanothus ophiochilus (a California endangered shrub known from only two populations) when it hybridizes with a much more numerous and widespread member of its genus? In this particular instance, hybrids colonize areas of manmade soil disturbance. Is genetic material moving from the more common species into the rare species? If so, the result may be the genetic dilution of the rare species, a situation referred to as "genetic swamping." Is genetic swamping a serious threat to this and other rare and localized species?
(2) What are the phylogenetic relationships within taxa? For example, what are the phylogenetic relationships within Pituohphus melanoleucus, the species that contains gopher snakes, pine snakes (one of the pine snakes, the Louisiana pine snake, is a Threatened taxon), and the bull snake? And,
(3) How does hybridization effect the interpretation of phylogenetic relationships? For example, in the P. melanoleucus complex mentioned above, what role have the proximity of Pleistocene refugia and possible hybridization between morphologically distinct subspecies (the bull snake and the Louisiana pine snake, for example) played in the topology of DNA phylogenies vs. the classical phylogeny based on morphology? Will a recently published mitochondrial DNA phylogeny agree with a nuclear gene phylogeny being generated in my lab? And, will either of these molecular phylogenies agree with the traditional taxonomy based on morphology? Or, for a plant example, a phylogeny based on the chloroplast genome shows that individuals in pine forests consisting of populations of Pinus hartwegii and P. montezumae in Mexico that occur on isolated mountains are more closely related to each other than they are to con-specifics that occur on different mountains. That is, a phylogeny based on chloroplast DNA groups populations that include both species geographically rather than by species. Is this phenomenon widespread?
Lastly, and on a somewhat different research trajectory is a study initiated in the spring of 2000 into the basic ecology of the western spadefoot toad, Scaphiopus hammondii. Because so little is known about this toad, answers to any biological questions having to do with topics as diverse as physiology, population genetics, ecology, or even burrow site fidelity are interesting and potentially important. The recent technological innovation that allows research on this organism is very small transmitters that can be attached to individuals so that they can be found after an initial encounter.
2000. Matos, J. A. and B. A. Schaal. Chloroplast evolution in the Pinus montezumae complex: a coalescent approach to hybridization between P. hartwegii and P. montezumae. Evolution 54(4):1218-1233.
1998. Matos, Jennifer A. A coalescent approach to chloroplast genome relationships within and between populations of Pinus devoniana in Mexico. ALISO 17(2):145-156.
1994. Matos, Jennifer A. Pinus hartwegii and P. rudis: a critical assessment. Systematic Botany 20(1):6-22.