You Are What You Grow by Rose Wong, graphite and digital.source:rebloggy.com

为大家带来环境科学-生态学研究领域里的顶级期刊Ecology Letters七月最新论文：1.脑部的大小对男生来说“然并卵” —— 孔雀鱼脑的大小，影响捕食威胁下雌性孔雀鱼的生存；2.植物啪啪啪地图 —— 通过植物交配系统预测植物地理分布范围的大小；3.微生物恢复力vs.历史偶然性对环境变化的响应；4.环境变化和种群对全球变化的响应。

source:wordpress.com

孔雀鱼脑的大小，影响捕食威胁下雌性孔雀鱼的生存

不同脊椎动物脑的大小多样性差异显著，但人们对物种间相互作用、如何影响物种脑的大小，知之甚少。

该研究选择了脑部大小不同的孔雀鱼作为研究对象，探讨在自然环境中，孔雀鱼在捕食天敌的威胁下，孔雀鱼脑部的大小对孔雀鱼生存的影响。

研究发现，脑大的雌性比脑小的雌性存活率高13.5%；然而，脑部大小对雄性的存活率，并没有显著影响。

Male Guppies Poecilia reticulata. source:thinkfish.co.uk

该研究猜测，脑大的雌性孔雀鱼，它们在认知方面具有很大的优势，这使得它们能够更好地逃避捕食；脑大的雄性孔雀鱼，色彩更加鲜艳，而这一点会抵消了脑大潜在的优势。

该研究的结论：首次提供了关于营养关系，能够影响脑进化大小的实验证据。

论文原文

Brain size affects female but not male survival under predation threat

Alexander Kotrschal1,2,*, Séverine D. Buechel1,2, Sarah M. Zala2, Alberto Corral-Lopez1, Dustin J. Penn2 andNiclas Kolm1

Ecology Letters, Volume 18, Issue 7, pages 646–652, July 2015

Abstract

There is remarkable diversity in brain size among vertebrates, but surprisingly little is known about how ecological species interactions impact the evolution of brain size. Using guppies, artificially selected for large and small brains, we determined how brain size affects survival under predation threat in a naturalistic environment. We cohoused mixed groups of small- and large-brained individuals in six semi-natural streams with their natural predator, the pike cichlid, and monitored survival in weekly censuses over 5 months. We found that large-brained females had 13.5% higher survival compared to small-brained females, whereas the brain size had no discernible effect on male survival. We suggest that large-brained females have a cognitive advantage that allows them to better evade predation, whereas large-brained males are more colourful, which may counteract any potential benefits of brain size. Our study provides the first experimental evidence that trophic interactions can affect the evolution of brain size.

source:inkyleaves.com

通过植物交配系统预测植物地理分布范围的大小

物种的地理分布范围具有很大的差异，即使是近亲物种，分布范围也有可能具有几个数量级大小的差距。

该研究通过分析数百种物种，包括20个属15个科分布的数据，发现：通过自花授粉繁殖的植物物种，与需要两个亲本进行繁殖的物种相比，前者具有更大的地理分布范围。

进一步分析表明，导致这种关系变化的自主受精，并不受到与物种进化关联的多倍性，或年生活史特征的驱动。

此外，自交物种发生在高纬度，并且因为他们的进化趋异，自交者和杂交者的分布范围，这当中的差异会随着时间的增加而增加。

综上所述，这些结果表明自主繁殖 —— 一个关键的生物特征，能够消除交配限制，从而增加物种建立的可能性，增加物种分布范围。

论文原文

Geographic range size is predicted by plant mating system

Dena Grossenbacher1,*, Ryan Briscoe Runquist1, Emma E. Goldberg2 andYaniv Brandvain1

Ecology Letters, Volume 18, Issue 7, pages 706–713, July 2015

Abstract

Species' geographic ranges vary enormously, and even closest relatives may differ in range size by several orders of magnitude. With data from hundreds of species spanning 20 genera in 15 families, we show that plant species that autonomously reproduce via self-pollination consistently have larger geographic ranges than their close relatives that generally require two parents for reproduction. Further analyses strongly implicate autonomous self-fertilisation in causing this relationship, as it is not driven by traits such as polyploidy or annual life history whose evolution is sometimes correlated with selfing. Furthermore, we find that selfers occur at higher maximum latitudes and that disparity in range size between selfers and outcrossers increases with time since their evolutionary divergence. Together, these results show that autonomous reproduction—a critical biological trait that eliminates mate limitation and thus potentially increases the probability of establishment—increases range size.

source:canadiangardening.com

土壤过程（比如碳循环）对未来气候变化的响应，主要取决于复杂的微生物群落，但是大多数生态系统模型假定微生物的功能具有一定的恢复性，并且能够从简单参数，比如：生物量和温度等来预测。

该研究认为，历史偶然性会改变这些影响，因为微生物功能取决于先前的条件或生物群。微生物功能的恢复力受到生理的群落，或者适应性变换的驱动。而历史偶然性，可能会导致历史环境的影响，或优先效应和生物抗性共同影响。

通过模拟微生物种群对环境变化的响应，该研究证明了历史环境会限制土壤功能，其限制程度取决于之前环境背景变化的范围大小。例如在不变环境中的微生物类群与不断变化环境中的微生物类群相比，它对于环境变化更加敏感，从而导致其对环境功能适应性较差。

论文原文

Resilience vs. historical contingency in microbial responses to environmental change

Christine V. Hawkes* andTimothy H. Keitt

Ecology Letters, Volume 18, Issue 7, pages 612–625, July 2015

Abstract

How soil processes such as carbon cycling will respond to future climate change depends on the responses of complex microbial communities, but most ecosystem models assume that microbial functional responses are resilient and can be predicted from simple parameters such as biomass and temperature.

Here, we consider how historical contingencies might alter those responses because function depends on prior conditions or biota. Functional resilience can be driven by physiological, community or adaptive shifts; historical contingencies can result from the influence of historical environments or a combination of priority effects and biotic resistance.

By modelling microbial population responses to environmental change, we demonstrate that historical environments can constrain soil function with the degree of constraint depending on the magnitude of change in the context of the prior environment. For example microbial assemblages from more constant environments were more sensitive to change leading to poorer functional acclimatisation compared to microbial assemblages from more fluctuating environments. Such historical contingencies can lead to deviations from expected functional responses to climate change as well as local variability in those responses. Our results form a set of interrelated hypotheses regarding soil microbial responses to climate change that warrant future empirical attention.

source:lizzieharper.co.uk

物种对环境变化（比如全球变暖）的响应，不仅仅受平均条件变化的影响，也受自然和人类活动导致的环境波动的影响。为了在全球变化背景下，有效地实施相关策略，来保护生物的多样性，这需要预测环境变化是如何影响物种生态和进化过程。

该文章回顾了最近的理论和实证研究来评估：

（1）种群是如何响应环境变化的。

（2）环境变化是如何影响种群对平均条件变化的响应。并概述了应用物种特性，比如系统发育史和体重等，来预测他们在未来环境变化下对全球变化的响应。

论文原文

Environmental variation and population responses to global change

Callum R. Lawson1,*, Yngvild Vindenes2, Liam Bailey3 andMartijn van de Pol1,3

Ecology Letters, Volume 18, Issue 7, pages 724–736, July 2015

Abstract

Species' responses to environmental changes such as global warming are affected not only by trends in mean conditions, but also by natural and human-induced environmental fluctuations. Methods are needed to predict how such environmental variation affects ecological and evolutionary processes, in order to design effective strategies to conserve biodiversity under global change. Here, we review recent theoretical and empirical studies to assess: (1) how populations respond to changes in environmental variance, and (2) how environmental variance affects population responses to changes in mean conditions. Contrary to frequent claims, empirical studies show that increases in environmental variance can increase as well as decrease long-term population growth rates. Moreover, environmental variance can alter and even reverse the effects of changes in the mean environment, such that even if environmental variance remains constant, omitting it from population models compromises their ability to predict species' responses to changes in mean conditions. Drawing on theory relating these effects of environmental variance to the curvatures of population growth responses to the environment, we outline how species' traits such as phylogenetic history and body mass could be used to predict their responses to global change under future environmental variability.