Abstract
AbstractTo predict extinction, we must understand the processes leading to terminal population decline. Once a critical threshold of population size is reached, small environmental perturbations can push a species over the cliff‐edge to extinction, so the main drivers of extinction are the factors that cause the initial reduction in population size. Most studies of population decline leading up to extinction focus on modern species in a human‐dominated world. The drivers of population decline leading to non‐human mediated extinctions are less well known but changes in climate are arguably the most widely invoked mechanism. Here, we report data on >16,000 individuals of the planktonic foraminifer Globoconella puncticulata from six sites in the Atlantic Ocean along an 83 degree‐long latitudinal transect, over a 600,000‐years interval leading up to the species’ global extinction during the late Pliocene‐earliest Pleistocene intensification of Northern Hemisphere glaciation. We show changes in geographic range, abundance, and body size. We find that populations do not follow a North‐to‐South sequence in extinction as Earth cooled and developed large ice sheets in the high latitudes of the Northern Hemisphere. Instead, our results suggest that (a) populations are differentially adapted to local environmental conditions such as nutrient availability, (b) population dynamics in core populations differ from those at the edge of their range, and (c) individual population responses to external pressures are essential to understanding the drivers of global extinction. Our study demonstrates the potential to transform our understanding of extinction dynamics through spatially replicated sampling of the highly resolved marine microfossil record.
Highlights
To predict extinction, it is crucial to understand the processes leading to population decline
Our results suggest that (a) populations are differentially adapted to local environmental conditions such as nutrient availability, (b) population dynamics in core populations differ from those at the edge of their range, and (c) individual population responses to external pressures are essential to understanding the drivers of global extinction
G. puncticulata disappeared from tropical Site 925 for much longer intervals of up to ∼100 kyr
Summary
It is crucial to understand the processes leading to population decline. Paleoceanography and Paleoclimatology the point where small external perturbations can push a species over the cliff-edge to extinction (Gilpin & Soulé, 1986; Hedrick et al, 1996; Raup, 1981). Because these modest perturbations would likely have been more readily absorbed by healthy populations, the main drivers of extinction are the factors that reduce population size initially and enhance extinction risk (Hedrick et al, 1996; Raup, 1981). To understand extinction, long-term records of biotic and abiotic change preceding extinction are needed
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.