Conifer pages

Mexicanconifers.org is the lab web page of David Gernandt. Visitors can find pages with species lists of Mexican conifers, information on current and past students, ongoing herbarium database capturing projects, molecular protocols, course offerings, and links to events at the Instituto de Biología, UNAM.

Mexican Conifers

Six extant conifer families, 10 genera, and approximately 75 species occur naturally in Mexico, making it a world center of diversity.

Pine species

Pinus montezumae

Pinus montezumae, Distrito Federal.

With 110-120 species, the genus Pinus (pines) includes more living species than any other genus of conifer, and Mexico has more native pine species than any other country.

The pines of Mexico have been the subject of two fairly recent treatments, one by Jesse Perry in 1991 and the other by Aljos Farjon and the late Brian Styles in 1997. Perry was a "splitter" of species, recognizing over 60 for Mexico, while Farjon, a "lumper", recognized fewer than 45. An intermediate number may be more reasonable, somewhere around 50. A list of our currently recognized species can be found here.

Conifer phylogeny

The main research interest of our lab group is in the systematics and evolution of conifers, particularly New World members of the pine family (Pinaceae).

We characterize the pattern of DNA substitutions and use those patterns to infer species relationships and to reconstruct their evolutionary history. We are also tying these DNA based inferences with the fossil record to estimate the time of diversification of Pinaceae lineages.

Conservation genetics

For a century, the viability of the only population of the Guadalupe cypress (Callitropsis guadalupensis), located on Isla Guadalupe, Baja California, was threatened from grazing by introduced goats. The goats were eradicated a few years ago, but last fall a large fire burned much of the forest.

We are characterizing the population structure of the endangered Guadalupe cypress using chloroplast markers.

DNA barcoding

We are participating in an international effort to generate short, standardized DNA sequence reads that will permit the identification of species. One question of interest to us is whether the DNA markers being used will be adequate for distinguishing endangered species.

Check back by the end of summer '09 and we should have DNA barcodes for a few hundred species of conifers, cacti, and orchids.