ハリケーンが自然選択を引き起こす要因であることを研究(URI’s Jason Kolbe studying hurricanes as a source of episodic natural selection)

2025-12-11 ロードアイランド大学(URI)

University of Rhode Islandの生物学部長ジェイソン・コルブ教授らの研究は、ハリケーンが断続的な「自然選択」の要因になることを示している。研究チームは、米国南東部に広がる侵入種のアノールトカゲ(Anolis sagrei)を対象に、ハリケーンによって強風下で有利になる形質がどのように選択されて進化に影響するかを長期的に調べた。研究では、ハリケーンの頻度が高い地域では、長い脚や大型の足裏パッドといった風に耐えて体を保持する能力が高い形質を持つ個体が多いことが確認された。このことは、強風という極端な気象イベントが生物の形態的・進化的変化に重要な役割を果たしていることを示す。また、人為的な気候変動によりハリケーンの強度と頻度が増すと、種の進化的経路が変わる可能性があるという。コルブ教授は、これらの「エピソード的自然選択」の理解を深めるため、他の種でも調査が必要だとしている。ハリケーン-induced selectionは、種の適応と進化の動態を解明する重要なモデルとなる。

ハリケーンが自然選択を引き起こす要因であることを研究(URI’s Jason Kolbe studying hurricanes as a source of episodic natural selection)
A new study led by URI’s Jason Kolbe examines adaptive selection in Anolis lizards in the southeastern U.S. (Photos / J. Kolbe)

<関連情報>

ハリケーンに対する形態学的およびゲノム的反応は、生物学的侵入中に発生し、持続する Morphological and genomic responses to hurricanes arise and persist during a biological invasion

Jason J. Kolbe, Sean T. Giery, Ansley S. Petherick, +1 , and Dan G. Bock
Proceedings of the National Academy of Sciences  Published:November 17, 2025
DOI:https://doi.org/10.1073/pnas.2517322122

Significance

Climate change is increasing the frequency and severity of extreme weather events. Research shows hurricanes are a source of strong natural selection, favoring traits that enhance the clinging ability of lizards under strong winds. Investigating the invasion of the brown anole, we found that populations experiencing more hurricanes had longer limbs and larger toepads, trait values that increase clinging performance. This signature was mirrored at the genetic level, with several genomic regions showing strong associations with hurricane frequency and limb length, as well as extreme differentiation among populations. Our results suggest that increases in the frequency and strength of hurricane-induced selection will alter the balance of selective pressures on limbs and toepads, reshaping morphological and genomic variation in wild populations.

Abstract

Hurricanes can be a source of strong, episodic natural selection, especially for coastal and island populations. In Anolis lizards, selection favors morphological traits that enhance clinging performance under hurricane-force winds. However, we know little about the longer-term persistence of morphological and genomic responses to these pulse-like events. To address this limitation, we capitalized on the well-documented history of hurricanes and spread of the invasive brown anole lizard, Anolis sagrei, over the past 130 y in the southeastern United States. We used 30 sites with estimates of the number of hurricanes experienced since population establishment. We found that hurricane frequency is consistently related to morphological trait values that increase clinging performance—longer limbs and larger toepads. In contrast, traits with no known connection to clinging ability were not related to hurricane frequency. Our genomic results show that despite a complex genetic architecture for most traits, populations retain a signature of hurricane-mediated selection, with several loci being strongly associated with both hurricane frequency and longer limbs. Further, we found that hurricanes are a more persistent driver of among-population genomic differentiation than other environmental variables. These results solidify hurricanes as a major force shaping morphological and genomic variation in Anolis lizards. They also highlight how the evolutionary trajectories of populations will likely be altered as climate change modifies historical patterns of natural selection, such as those involving extreme weather events.

1903自然環境保全
ad
ad
Follow
ad
タイトルとURLをコピーしました