Dpto. Geodinámica, Estratigrafía y Paleontología, Facultad de Ciencias Geológicas, Universidad Complutense de Madrid, ES-, 28040, Madrid, Spain.
Dpto. Biología y Geología, Física y Química Inorgánica, ESCET, Universidad Rey Juan Carlos, C/ Tulipán s/n, ES-, 28933, Móstoles, Madrid, Spain.
Sci Rep. 2018 Jun 28;8(1):9780. doi: 10.1038/s41598-018-28000-0.
Climate change is not only evident, but its implications on biodiversity are already patent. The scientific community has delved into the limitations and capabilities of species to face changes in climatic conditions through experimental studies and, primarily, Species Distribution Models (SDMs). Nevertheless, the widespread use of SDMs comes with some intrinsic assumptions, such as niche conservatism, which are not always true. Alternatively, the fossil record can provide additional data to solve the uncertainties of species' responses to climate change based on their history. Using a combined environmental (niche overlap indices) and geographical approach (temporal transferability of SDMs), we assessed the niche conservatism of Microtus cabrerae throughout its evolutionary history: the Late Pleistocene and the Holocene. The set of analyses performed within this timeframe provides a broad view pointing to a shift in the realized climatic niche of the species. Specifically, M. cabrerae exhibited a broader niche during glacial times than interglacial times, expanding towards novel conditions. Hence, the species might have developed an adaptive ability, as a consequence of mechanisms of local adaptation or natural pressures, or just be preadapted to cope with the novel environment, due to expansion into an unfilled portion of the niche. Nevertheless, the more restricted realized niche during last interglacial times reveals that the species could be close to its physiological limits.
气候变化不仅明显，而且其对生物多样性的影响已经显而易见。科学界通过实验研究，主要是物种分布模型（SDM），深入研究了物种面对气候变化的限制和能力。然而，SDM 的广泛应用伴随着一些内在的假设，如生态位保守性，这些假设并不总是正确的。相反，化石记录可以提供额外的数据，以解决物种对气候变化的反应的不确定性，这些数据是基于它们的历史。我们使用了一种结合环境（生态位重叠指数）和地理方法（SDM 的时间可转移性），评估了 Microtus cabrerae 在其进化历史中的生态位保守性：晚更新世和全新世。在这个时间框架内进行的一系列分析提供了一个广泛的视角，表明该物种的实际气候生态位发生了变化。具体来说，M. cabrerae 在冰川时期的生态位比间冰期更宽，向新的条件扩展。因此，由于局部适应或自然压力的机制，或者只是由于扩展到生态位的未填充部分而预先适应了新环境，该物种可能已经发展出了一种适应能力。然而，在最后一次间冰期期间，更受限制的实际生态位表明该物种可能接近其生理极限。
