Extinction and recolonization of coastal megafauna following human arrival in New Zealand

TitleExtinction and recolonization of coastal megafauna following human arrival in New Zealand
Publication TypeJournal Article
Year of Publication2014
AuthorsCollins C.J, Rawlence N.J, Prost S., Anderson C.NK, Knapp M., Scofield R.P, Robertson B.C, Smith I., Matisoo-Smith E.A, Chilvers B.L, Waters J.M
JournalProceedings of the Royal Society B-Biological Sciences
Date Published2014/07
Type of ArticleArticle
ISBN Number0962-8452
Accession NumberWOS:000336784500012
KeywordsaDNA; Ancient DNA; brown bears; climate; extinction; fauna; late pleistocene; model; New Zealand; pacific; Phocarctos hookeri; phocarctos-hookeri; population-genetics; priority effects; working

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.

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