Cactus Genomics

Prickly problems of cacti phylogeny

See allHide authors and affiliations

Science  24 Nov 2017:
Vol. 358, Issue 6366, pp. 1016
DOI: 10.1126/science.358.6366.1016-a

The genomes and relationships of columnar cacti, such as the saguaro, have been resolved.


The evolutionary history of cacti has been difficult to resolve. Copetti et al. sequenced the genomes of four species of columnar cacti, including the icon of the American Southwest, the saguaro cactus. A single optimal phylogenetic tree was generated through analysis of these genomes. First, the connections between species confounded by parallel evolution had to be disentangled. Paradoxically, the relationships among most genes were discordant and did not fit the hypothesized species relationships. This was attributed to many factors, including divergent population dynamics and long life spans, as well as gene flow via hybridization (introgression) and incomplete lineage sorting of convergent evolutionary changes (hemiplasy).

Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1706367114 (2017).

Navigate This Article