氣候變化常常改變在一個(gè)地區(qū)植物繁盛的地點(diǎn)和種類,，這可能導(dǎo)致依賴特定植物為食的動(dòng)物物種的滅絕。Catherine Badgley及其同事研究了來自巴基斯坦北部化石豐富的Siwalik化石記錄中的哺乳動(dòng)物化石,，結(jié)果發(fā)現(xiàn)了該地區(qū)的氣候在數(shù)百萬年的時(shí)間里從熱帶森林轉(zhuǎn)變?yōu)橄洳菰倪^程中,，許多動(dòng)物物種沒能適應(yīng)環(huán)境而滅絕了。這些結(jié)果與此前的發(fā)現(xiàn)相反,，此前的發(fā)現(xiàn)認(rèn)為全球氣候變化對(duì)哺乳動(dòng)物多樣性的影響較小,，人們認(rèn)為哺乳動(dòng)物可以輕易地遷移或者適應(yīng)變化的氣候。
Siwalik沉積物群包含了全世界得到了最好的研究和最完整的哺乳動(dòng)物化石記錄之一,，在一個(gè)2英里厚的沉積巖中含有從100萬年前到1800萬年前在該地區(qū)活動(dòng)的哺乳動(dòng)物的遺跡,。大約在800萬年前，隨著那里的氣候從熱帶森林氣候變成類似于今天東非的稀樹草原氣候,，幾乎所有依賴森林食物（例如水果和闊葉植物）的哺乳動(dòng)物都滅絕了,。這組作者說，牙齒化石顯示甚至一些食草動(dòng)物也滅絕了,，而且?guī)缀鯖]有新物種取代了那些消失的物種,。相關(guān)論文發(fā)表在美國《國家科學(xué)院院刊》（PNAS）上。（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS,， doi: 10.1073/pnas.0805592105,，Catherine Badgley,，David Pilbeam
Ecological changes in Miocene mammalian record show impact of prolonged climatic forcing
Catherine Badgley*,†, John C. Barry‡, Michèle E. Morgan‡, Sherry V. Nelson§, Anna K. Behrensmeyer¶, Thure E. Cerling*,‖, and David Pilbeam‡
+Author Affiliations
Abstract
Geohistorical records reveal the long-term impacts of climate change on ecosystem structure. A 5-myr record of mammalian faunas from floodplain ecosystems of South Asia shows substantial change in species richness and ecological structure in relation to vegetation change as documented by stable isotopes of C and O from paleosols. Between 8.5 and 6.0 Ma, C4 savannah replaced C3 forest and woodland. Isotopic historical trends for 27 mammalian herbivore species, in combination with ecomorphological data from teeth, show three patterns of response. Most forest frugivores and browsers maintained their dietary habits and disappeared. Other herbivores altered their dietary habits to include increasing amounts of C4 plants and persisted for >1 myr during the vegetation transition. The few lineages that persisted through the vegetation transition show isotopic enrichment of δ13C values over time. These results are evidence for long-term climatic forcing of vegetation structure and mammalian ecological diversity at the subcontinental scale.
