Botany

John Zaborsky, along with fellow UW Botany alumni Jeff Rose, Ricardo Kriebel, Bryan Drew, and Ken Sytsma have published a paper on the phylogenetics and biogeography of Sesamothamnus (Pedaliaceae) in American Journal of Botany. A phylogenetic tree based on 512 nuclear genes and entire plastomes was generated for Sesamothamnus. The nuclear and plastome data provided congruent phylogenies and showed that the species restricted to northeast Africa are sister to the species in southern Africa. Sesamothamnus shows a classic distributional pattern between these arid areas: the African Arid Corridor (AAC) disjunction. A hypothesis explaining this disjunction posits the former existence of a corridor of arid habitats that linked the two areas. Searching the literature, the authors found 73 examples of vascular plants that exhibit this distribution. Along with Sesamothamnus, time-calibrated splits were obtained for these groups, ranging from 34 Ma to the Pleistocene, with the majority dated to the late Miocene, Pliocene, and Pleistocene.

Most clades, including Sesamothamnus, appear associated with waves of aridification that shaped the biota of Africa during this time, with the corridor opening and closing repeatedly. The rise of C4 and CAM photosynthesis, evolution of succulence and spiny stems, and the diversification of bovids also occurred during this time. The data show that the AAC formed and reformed many times, allowing the ancestors of these plants to frequently migrate from the southwest to the northeast. The pattern is complicated, and phylogenetic studies of widely distributed African genera may reveal more AAC disjunctions between sister taxa.
https://bsapubs.onlinelibrary.wiley.com/doi/10.1002/ajb2.70192

Joseph Walston (Cameron Lab) was one of four graduate students to win the campus-wide UW—Madison Award for Mentoring Undergraduates in Research, Scholarly and Creative Activities given by the Office of the Provost and the Division for Teaching and Learning. He was recognized for mentoring his group of 8 mentees (including three senior theses) called the PitcherPals. (Photo shows Joseph (at right) with his first senior thesis student, Jon Martin.)

This year, Botany 300 Plant Anatomy students were given the option to write a paper or to create a video for a special assignment. The goal for the video was to be able to explain scientific concepts to the general public. One of the students, Mason Borchardt, went above and beyond with his production! Check out the video at the link:

Plant Anatomy Project Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube.