新一期英國《自然·通信》雜志刊登研究報告說,，氣候變化已明顯影響了芬蘭不同顏色貓頭鷹群體的比例,。由于近30年冬天越來越溫暖，當?shù)赝N群不同顏色的貓頭鷹在生存競爭中的優(yōu)劣地位隨之變化,，導致它們的比例發(fā)生變化,。
芬蘭赫爾辛基大學等機構(gòu)研究人員報告說，他們對當?shù)孛麨?ldquo;灰林鸮”的一種貓頭鷹跟蹤研究了幾十年,。這種貓頭鷹分為棕色和灰色兩種顏色,，過去棕色貓頭鷹數(shù)量相對較少，但近30年數(shù)量呈明顯上升趨勢,，棕色貓頭鷹在當?shù)刎堫^鷹群體中所占比例已從30％上升到約50％,。
研究人員認為，棕色“灰林鸮”的增多與氣候變化有關,。通常在嚴酷的冬天,，棕色“灰林鸮”與灰色“灰林鸮”相比在競爭中處于劣勢。一是因為在寒冬大雪中,，前者更容易被其天敵發(fā)現(xiàn),，另外棕色“灰林鸮”新陳代謝率更高，意味著它們需要更多食物,，這在缺乏食物的冬天也成為劣勢之一,。
因此，在過去天氣更為寒冷時,，棕色“灰林鸮”的數(shù)量并不多,。而近30年隨著全球氣候變暖，冬天越來越暖和,，棕色“灰林鸮”在競爭上的劣勢相對減少,，其數(shù)量也就出現(xiàn)增長.（生物谷Bioon.com）
生物谷推薦原文出處：
Nature Communications doi:10.1038/ncomms1213
Climate change drives microevolution in a wild bird
Patrik Karell,1 Kari Ahola,2 Teuvo Karstinen,3 Jari Valkama4 & Jon E. Brommer1
To ensure long-term persistence, organisms must adapt to climate change, but an evolutionary response to a quantified selection pressure driven by climate change has not been empirically demonstrated in a wild population. Here, we show that pheomelanin-based plumage colouration in tawny owls is a highly heritable trait, consistent with a simple Mendelian pattern of brown (dark) dominance over grey (pale). We show that strong viability selection against the brown morph occurs, but only under snow-rich winters. As winter conditions became milder in the last decades, selection against the brown morph diminished. Concurrent with this reduced selection, the frequency of brown morphs increased rapidly in our study population during the last 28 years and nationwide during the last 48 years. Hence, we show the first evidence that recent climate change alters natural selection in a wild population leading to a microevolutionary response, which demonstrates the ability of wild populations to evolve in response to climate change.
