This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: As the climate changes, species face a critical question: Can they evolve quickly enough to keep pace with their changing environment? A new study published in the Proceedings of the National Academy of Sciences suggests that, for at least one long-lived seabird, the answer is generally no.
Although evolutionary adaptation can improve the prospects of black-browed albatross populations, the study finds that evolution alone is unlikely to prevent population declines under projected climate change, but substantially limiting greenhouse-gas emissions improves the species' chances of survival, reducing projected extinction probability by approximately half. "Climate mitigation contributes more to population persistence than evolutionary adaptation in a long-lived seabird," co-authored by Woods Hole Oceanographic Institution (WHOI) senior scientist Stéphanie Jenouvrier and colleagues, combines more than three decades of demographic and phenotypic data on black-browed albatrosses, a seabird native to the Southern Ocean and seas. The species is pelagic, meaning it spends most of its life gliding far out at sea.
Researchers used an eco-evolutionary population model and climate projections to examine not only how climate affects population dynamics but also how natural selection and evolutionary change might alter the population's response. "Evolution can help populations cope with environmental change, but our results show that it has limits," said Jenouvrier. "For this long-lived seabird, limiting the magnitude of climate change has a much greater effect on population persistence than evolutionary adaptation alone." "Evolutionary rescue" occurs when adaptive evolutionary change allows a population to avoid extinction following environmental deterioration.
It is often proposed as a potential buffer against biodiversity loss as the climate changes. But whether evolutionary responses can occur quickly enough remains uncertain, particularly for long-lived species. Because these species have relatively long generation times, environmental conditions can deteriorate and populations can decline before evolutionary responses have time to substantially affect population trajectories.
"Some traits, such as wing length, can help young birds survive, but the key question is whether evolutionary changes in those traits can happen fast enough to keep pace with climate change," said co-author Joanie Van de Walle of the Université du Québec à Rimouski. Researchers built a computer model that combined information about albatross demography, how traits are passed from parents to offspring, and projections of future climate. The model tracked how differences among individuals in physical traits, behavior and breeding timing affected survival and reproduction, allowing natural selection and evolutionary change to emerge over time.
It also accounted for uncertainty in population changes and natural fluctuations in climate. Under the relatively stable climate conditions of the past, allowing the albatross population to adapt through evolution led to larger projected populations. But under future warming scenarios, evolutionary changes generally were not enough to prevent the population from declining.
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