Robert A. Browne

Professor of Biology

243 Winston Hall
(336) 758-5569
brownera@wfu.edu

Life History and Reproductive Strategies in Brine Shrimp (Artemia)

Potential Graduate Student Projects

1. Competition between parthenogenetic and sexual species, variables would include clonal types, ploidy level, different species, as well as abiotic variables such as temperature and salinity. A further area of interest would be competition experiments in sealed jars, partly to determine how long self-sufficient ecosystems can be maintained with light as the only external input.

2. Mating experiments between different species and populations of Artemia to determine pre- and post- reproductive isolating mechanisms. (See TREE 16, pp 369 and 338.)

3. An interesting twist is to determine the ability of males to differentiate between sexual and parthenogenetic females.

4. Look at degree and "rates" of speciation in sexual and parthenogenetic Artemia (including multiclonal diploids and polyploids).
   Map genetic divergence (estimated by mtDNA sequence, RFLPs, allozymes).
   Map lifespan and reproductive trait divergence (12- 15 traits).
   Map ecological niches (lab determined temp/salinity niches) and niches occupied
           in the field.

Genetic Fragmentation in the Southern Appalachians

Potential Graduate Student Projects

1.   Woodland jumping mouse (Napaeozapas insignis). Locally abundant in spruce-fir forests but appears to have large gaps between populations. We would like to estimate genetic diversity and gene flow via mtDNA sequence using universal small mammal primers. This study would dovetail nicely with our previous studies of spruce-fir populations of northern flying squirrels, redback voles, red squirrels and shrews. From previous work we know where the populations are locally abundant. This could be expanded beyond Southern Appalachians to northern U.S. and Canada.

 2.  Salamanders. There are a number of salamander species whose range is entirely or mostly limited to high altitude spruce-fir forests. We’ve done extensive work on the pygmy salamander, but other species of interest are Plethodon jordani and the Cheat Mt. salamander which has very limited distribution in the Alleghenies in VA and WV.

 3.   Flightless beetles. There are numerous species of relictual and some endemic species of beetles that occur in the Appalachians. There’s the possibility of collaboration with Bill Connor in our department.

Population Genetics and Ecology in the Galapagos

Potential Graduate Student Projects

1. Opuntia (prickly pear cactus). These are analagous to trees in the Galapagos in that they can reach up to 40 ft in height on some islands but are shrubs on other islands. There is widespread morphological and taxonomic diversity but extremely limited allozymic diversity. We have complete collections in the ultracold from all major islands and from coastal Ecuador. The next step is to do molecular analysis (e.g.chlorplast DNA analysis or molecular fingerprinting).

2.   Galapagos doves. Endemic to Galapagos. Estimation of genetic divergence between Galapagos and mainland S. America populations and among Galapagos islands. Possible ecological study.
   

4.   Yellow warblers. Males have pronounced red caps on their heads. How important is this regarding mate female attraction, territorial size and protection, mating and reproductive success? Band male warblers at CDRS, possibly manipulate size and intensity of red cap and/or streaks on breast.  Red caps may also be an important male discrimination factor (i.e. prereproductive isolating mechanism) between migrant and nonmigrant yellow warbler subspecies (or any of the numerous subspecies of yellow warbler). Another important factor could be differences in song characters (possible collaboration with Martin Beebe, graduate student of Steve Nowicki at Duke). Why do some areas (subspecies) have pronounced red caps and others do not?  Is the cost of red cap higher in some areas than other? See TREE 16: p397

5.   Other Galapagos birds; mostly genetic divergence studies. We do have universal avian primers for mt DNA and only blood would be needed.