Life in varying environments: experimental evidence for delayed effects of juvenile environment on adult life history
Life in varying environments: experimental evidence for delayed effects of juvenile environment on adult life history
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DOI：
10.1111/j.1365-2656.2011.01937.x
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发表时间：
2012-05-01
影响因子：
4.8
通讯作者：
Mappes, Tapio
中科院分区：
文献类型：
--
作者：
Helle, Heikki;Koskela, Esa;Mappes, Tapio
1. 早期发育过程中经历的环境对成年表型的影响已开始引起人们对各种分类群的极大兴趣。关于幼年环境的长期影响已有一些证据，但仍缺乏野生动物的重复实验研究。2．在这里，我们报告了第一个在野生哺乳动物中进行的重复实验，该实验研究了幼年和成年环境对个体健康（繁殖、生存和健康）的长期影响。银行田鼠（Myodes glareolus）个体的早期发育发生在有食物补充或无补充的室外围栏中。夏季过后，成年个体相应地改变到与越冬相似或相反的资源环境。3．成体环境对雌性的繁殖成功率具有压倒性的影响，因此在补充食物的围栏中越冬的雌性有更高的繁殖概率并提前开始繁殖。然而，它们的窝仔特征是由幼年环境决定的：雌性最初在有食物补充的条件下生长，随后产下更大的窝仔，幼仔也更大，并且性别比例偏向雄性。 4．在雄性中，在未补充的条件下生长的个体在冬季无论成体环境如何都具有最高的存活率，而在雌性中，幼体和成体环境都对其生存没有显着影响。由血液学参数决定的春季田鼠的生理状况也受到幼年环境（血浆蛋白和雄性睾酮）和成年环境（红细胞比容）的不同影响。5．我们的研究结果表明，（i）田鼠的生活史轨迹并不严格针对特定环境；（ii）对当前条件的可塑性生活史反应实际上可能是由幼年环境的延迟效应引起的。更一般地说，这些结果对于理解延迟生活史效应的机制以及认识其种群动态后果非常重要。
1. The effects of environment experienced during early development on phenotype as an adult has started to gain vast amounts of interest in various taxa. Some evidence on long-term effects of juvenile environment is available, but replicated experimental studies in wild animals are still lacking.2. Here we report the first replicated experiment in wild mammals which examines the long-term effects of juvenile and adult environments on individual fitness (reproduction, survival and health). The early development of bank vole (Myodes glareolus) individuals took place in either food-supplemented or un-supplemented outdoor enclosures. After the summer, adult individuals were reciprocally changed to either a similar or opposite resource environment to overwinter.3. Adult environment had an overriding effect on reproductive success of females so that females overwintering in food-supplemented enclosures had a higher probability of breeding and advanced the initiation of breeding. However, the characteristics of their litters were determined by juvenile environment: females initially grown in food-supplemented conditions subsequently produced larger litters with bigger pups and a male-biased sex ratio.4. In males, individuals growing in un-supplemented conditions had the highest survival irrespective of adult environment during winter, whereas in females, neither the juvenile nor adult environments affected their survival significantly. The physiological condition of voles in spring, as determined by haematological parameters, was also differentially affected by juvenile (plasma proteins and male testosterone) and adult (haematocrit) environments.5. Our results suggest that (i) life-history trajectories of voles are not strictly specialized to a certain environment and (ii) the plastic life-history responses to present conditions can actually be caused by delayed effects of the juvenile environment. More generally, the results are important for understanding the mechanisms of delayed life-history effects as well as recognizing their population dynamic consequences.