Extinction and recolonization of coastal megafauna following human arrival in New Zealand.
Extinctions can dramatically reshape biological communities. As a case in point, ancient mass extinction events apparently facilitated dramatic new evolutionary radiations of surviving lineages. However, scientists have yet to fully understand the consequences of more recent biological upheaval, such as the megafaunal extinctions that occurred globally over the past 50 kyr. New Zealand was the world's last large landmass to be colonized by humans, and its exceptional archaeological record documents a vast number of vertebrate extinctions in the immediate aftermath of Polynesian arrival approximately AD 1280. This recently colonized archipelago thus presents an outstanding opportunity to test for rapid biological responses to extinction. Here, we use ancient DNA (aDNA) analysis to show that extinction of an endemic sea lion lineage (Phocarctos spp.) apparently facilitated a subsequent northward range expansion of a previously subantarctic-limited lineage. This finding parallels a similar extinction-replacement event in penguins (Megadyptes spp.). In both cases, an endemic mainland clade was completely eliminated soon after human arrival, and then replaced by a genetically divergent clade from the remote subantarctic region, all within the space of a few centuries. These data suggest that ecological and demographic processes can play a role in constraining lineage distributions, even for highly dispersive species, and highlight the potential for dynamic biological responses to extinction.
Allan Wilson Centre for Molecular Ecology and Evolution, Department of Zoology, University of Otago, Dunedin 9016, New Zealand catherine.collins01@gmail.com.
Catherine J
CJ
Collins
Allan Wilson Centre for Molecular Ecology and Evolution, Department of Zoology, University of Otago, Dunedin 9016, New Zealand.
Nicolas J
NJ
Rawlence
Allan Wilson Centre for Molecular Ecology and Evolution, Department of Anatomy, University of Otago, Dunedin 9016, New Zealand Department of Bioinformatics and Genetics, Swedish Museum of Natural History, 10405 Stockholm, Sweden Department of Integrative Biology, University of California, Berkeley, CA 94720-3140, USA.
Stefan
S
Prost
Scripps Institution of Oceanography, University of California, San Diego, CA 92093, USA.
Christian N K
CN
Anderson
Allan Wilson Centre for Molecular Ecology and Evolution, Department of Anatomy, University of Otago, Dunedin 9016, New Zealand School of Biological Sciences, Bangor University, Bangor, LL57 2UW, Wales, UK.
Michael
M
Knapp
Canterbury Museum, Christchurch 8013, New Zealand.
R Paul
RP
Scofield
Allan Wilson Centre for Molecular Ecology and Evolution, Department of Zoology, University of Otago, Dunedin 9016, New Zealand.
Bruce C
BC
Robertson
Department of Anthropology and Archaeology, University of Otago, Dunedin 9016, New Zealand.
Ian
I
Smith
Allan Wilson Centre for Molecular Ecology and Evolution, Department of Anatomy, University of Otago, Dunedin 9016, New Zealand.
Elizabeth A
EA
Matisoo-Smith
Department of Conservation, Marine Species and Threats, Wellington 6011, New Zealand.
B Louise
BL
Chilvers
Allan Wilson Centre for Molecular Ecology and Evolution, Department of Zoology, University of Otago, Dunedin 9016, New Zealand.
Jonathan M
JM
Waters
D063147:Animal Distribution; D000818:Animals; D001106:Archaeology; D004272:DNA, Mitochondrial / Q000235:genetics; D053476:Extinction, Biological; D005580:Fossils; D006801:Humans; D008969:Molecular Sequence Data; D009520:New Zealand; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D055110:Radiometric Dating; D046070:Sea Lions / Q000235:genetics / Q000502:physiology; D017422:Sequence Analysis, DNA; D046429:Spheniscidae / Q000235:genetics / Q000502:physiology
D004272:DNA, Mitochondrial
New Zealand; Phocarctos hookeri; aDNA; extinction; priority effects