Date:
04 - 04 August 2020
Event type:
Webinar, Workshop, Virtual event
Event status:
EVENT CLOSED
Speaker: Dr. Mairin Balisi, La Brea Tar Pits & Museum
Title: Ancient Originations, Recent Extinctions: Fossil Insights on Extant Carnivore Biodiversity
Abstract
How ecological traits influence organismal success is a recurring question in paleobiology, particularly as specialization toward extremes may act differently at various scales: traits benefitting an individual may disadvantage its population, species or clade. For example, the ecological specializations of large body size and hypercarnivory (diet over 70% meat) have evolved repeatedly in mammals; yet large hypercarnivores are thought to be trapped in a macroevolutionary “ratchet”, marching unilaterally toward extinction. I examined the relationship between specialization and success over the past 40 million years in North American canids (dogs), a group with considerable ecomorphological disparity and a dense fossil record.
Across all canids, a nonlinear relationship emerged between species duration and carnivory: species on either end of the carnivory spectrum tend to have shorter durations than middling species. In two of three canid subfamilies, large-hypercarnivore diversification appears constrained at the clade level, biasing specialized lineages to extinction. However, despite these shorter durations and elevated clade extinction, large hypercarnivores were not disadvantaged at the species level for most of canid history. Extinction was size- and carnivory-selective only at the Pleistocene-Holocene boundary 11,000 years ago, when large-scale biotic and abiotic impacts precipitated the rise of modern carnivore communities primarily comprising fewer predators and smaller species. This trophic and body-size downgrading has continued at the microevolutionary level, producing ecomorphological shifts perceptible in carnivoran species surviving to the modern-day.
Pal(a)eoPERCS: A weekly seminar series by Early Career Researchers in “Pal(a)eo” sciences
Tuesdays at 8am Pacific / 11am Eastern / 4pm UK / 5pm Central Europe time
Twitter: @PalaeoPERCS
Website: https://paleopercs.wordpress.com/
The Pal(a)eo PERCS Steering Committee
Dr. Rehemat Bhatia (NERC)
Dr. Catherine Davis (Yale University)
Dr. Andy Fraass (University of Bristol)
Dr. Christine Hall (University of Connecticut)
Dr. Elizabeth Sibert (Harvard University)
All seminars are closed captioned, and attendees are encouraged to contact the organisers in the case of any other accommodations required.