Yale Peabody Museum Summer Internships

Studying hybridization with the Viburnum lentago complex

Advisor: Patrick Sweeney with Prof. Michael Donoghue


Length: 6 weeks in the summer


Project Description:

Documenting and describing biodiversity are fundamental endeavors within evolutionary biology. A major area of research within the Peabody Museum Division of Botany and the affiliated Donoghue Lab (http://donoghuelab.yale.edu) revolves around understanding the evolutionary history of the flowering plant genus Viburnum. Part of this research centers on documenting morphological and genetic variation within the genus, with an aim towards better understanding species diversity.


The North American Viburnum Lentago clade (a kind of evolutionary group) is composed of six to seven species of shrubs and small trees. Three of the species are common in the eastern U.S. and overlap across large sections of their geographic ranges. These large areas of overlap are surprising because these species appear distinct in nature, despite successfully hybridizing in cultivation. Prelimary data on individuals in cultivation suggests that V. prunifolium may flower up to two weeks earlier than V. lentago and V. rufidulum, suggesting that the species boundaries have been maintained through the evolution of differing flowering times (referred to by evolutionary biologists as “flowering time displacement”). The Donoghue Lab has collected 186 individuals from across the range of all three species, including in northern Kentucky where V. prunifolium and V. rufidulum co-occur. In Kentucky, there was evidence for flowering time displacement, and we found few hybrids. Only three to four of 83 sequenced individuals showed signs of hybridization. We have not, however, visited the regions where V. prunifolium and V. lentago co-occur, and we do not know whether those species stagger their flowering time or if there is hybridization occurring in those regions. We hypothesize that V. prunifolium and V. lentago are maintaining their species boundaries by differentiating their flowering times.  The goal of this project is to survey specimens of V. prunifolium and V. lentago from the regions where they overlap, and then look for genetic evidence of hybridization.


This is a field-, collection-, and lab-based project. In May 2017, a student would travel with Elizabeth Spriggs and Michael Donoghue to natural areas in southern Pennsylvania and northern Ohio. In those areas, they would find, photograph, and collect specimens of V. prunifolium and V. lentago, specifically looking to find areas where the two species co-occur. Upon returning to Yale, the student would help with processing new specimens for inclusion in the Division of Botany collection, help with extracting DNA from newly collected specimens, and may have the opportunity to assist in phylogenetic analyses.



Stipend for lodging, food, etc.


Travel, lodging and meals for field work will be covered




CLICK HERE to apply!