Population genetics and inference of ecosystem history: an example using two Neotropical seasonally dry forest species

NACIRI-GRAVEN Y.; CAETANO S.; PENNINGTON, R.T.; PRADO, D.E.; SPICHIGER, R.

Neotropical Savannas and Seasonally Dry Forests: Plant Diversity, Biogeography and Conservation

CRC Press

Lugar: Boca Ratón, FL; Año: 2006; p. 409 - 424

In South America, many seasonally dry tropical forest (SDTF) species are found in different areas, all around the Amazon Basin and separated by thousands of kilometers. This pattern suggests that there may have been a wider expansion of SDTF in the cool-dry climates of the Quaternary. Alternatively, these current distribution patterns of SDTF may have been caused by long-distance dispersal events. In this chapter, we explain how population genetics and the coalescence theory can help in inferring SDTF history by means of the study of two representative forest trees, Astronium urundeuva (Anacardiaceae) and Geoffroea spinosa (Leguminosae). The results reveal a higher differentiation level for G. spinosa than for A. urundeuva using microsatellite markers (è = 0.151 versus 0.064; P< 0.01), which may reflect different dispersal abilities and historical events. The preliminary analysis of three chloroplast markers on A. urundeuva does not allow discrimination between the two hypotheses (vicariance versus dispersal).