Abstract Detail

A Botanist at the Extreme: Honoring the great contributions of Dr. Vicki A. Funk

Ackerfield, Jennifer [1], Siniscalchi, Carolina [2].

Diversification of Cirsium (Carduoideae: Compositae) in North America – Insights into a continental-scale radiation.

A major goal of evolutionary biology is to understand the abiotic and biotic factors that facilitate and/or promote diversification within lineages and shape species’ distribution patterns. The interplay of abiotic and biotic factors generates selective pressures, stimulating morphological diversity and adaptive innovations. Over time, species must either isolate in unaltered ecosystems, or diversify and adapt to changing abiotic and biotic pressures. The factors influencing diversification are often studied in lineages that have undergone radiations – adaptation of a lineage to changing biotic and/or abiotic conditions, and lineage (species) diversification from a single common ancestor. One such example of a continental-scale radiation is seen in Cirsium (i.e. “thistles”), with approximately 125 species in North America. Cirsium is a member of Compositae, one of the most speciose flowering plant families in the world, and comprises 99% of the subfamily Carduoideae in North America. Additionally, although some Cirsium are widespread, most native thistles are restricted to specific ecological niches and are narrowly limited in range. Thus, understanding the factors influencing diversification of Cirsium in North America has important insight into the global success of Compositae. Here, we use a time-calibrated phylogeny generated by high-throughput sequencing (Hyb-Seq) to: 1) estimate the timing of diversification for extant species, 2) estimate ancestral biomes and ranges for extant species, and 3) examine how diversification rates are associated with biome shifts and morphological traits, in particular those associated with hummingbird pollination.

1 - Denver Botanic Gardens, 909 York Street, Denver, CO, 80206, USA
2 - P.O. Box 2896, Apt 2, Mississippi State, MS, 39762, United States

Keywords:
Radiation
thistles
Diversification
North America.

Presentation Type: Symposium Presentation
Number: S4006
Abstract ID:177
Candidate for Awards:None