Are most samples of animals systematically biased? Consistent individual trait differences bias samples despite random sampling
Are most samples of animals systematically biased? Consistent individual trait differences bias samples despite random sampling
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DOI：
10.1007/s00442-012-2426-5
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发表时间：
2013-02-01
期刊：
影响因子：
2.7
通讯作者：
Biro, Peter A.
中科院分区：
文献类型：
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作者：
Biro, Peter A.
从野外抽取动物样本进行研究几乎是每个生物学家都做过的事情，但是尽管我们尽了最大的努力来获得随机的动物样本，“隐藏的”特征偏见可能仍然存在。例如，一致的行为特征可以独立于体型和性别等明显因素影响可捕获性，并且这些特征通常与其他可重复的生理和/或生活史特征相关。如果是这样，这些特征中的任何一个都可能存在系统抽样偏差。当然，这在多大程度上是一个问题，取决于偏见的程度，目前尚不清楚，因为群体中潜在的特征分布通常是未知的，或者是不可知的。事实上，我们目前关于抽样偏差的知识来自样本（而不是完整的人口普查），这些样本一开始就可能存在偏差。我有一个独特的机会，通过在四个没有鱼的小湖泊中分别播种相同密度的慢速、中速和快速生长的鱼，来创造归化的鱼类种群。使用不选择大小的取样方法，我观察到快速生长的鱼比缓慢生长的鱼被取样的可能性高两倍。这表明在一个重要的生活史特征（生长率）方面存在实质性和系统性的偏差。如果行为、生理和生活史特征之间的相关性如文献所示的那样广泛存在，那么许多动物样本可能会系统性地偏向于这些特征（例如，在收集动物用于实验室使用时），并影响我们对种群结构和丰度的推断。最后，我讨论了如何在动物种群中减少特定生理/行为/生活史类型的抽样偏差。
Sampling animals from the wild for study is something nearly every biologist has done, but despite our best efforts to obtain random samples of animals, 'hidden' trait biases may still exist. For example, consistent behavioral traits can affect trappability/catchability, independent of obvious factors such as size and gender, and these traits are often correlated with other repeatable physiological and/or life history traits. If so, systematic sampling bias may exist for any of these traits. The extent to which this is a problem, of course, depends on the magnitude of bias, which is presently unknown because the underlying trait distributions in populations are usually unknown, or unknowable. Indeed, our present knowledge about sampling bias comes from samples (not complete population censuses), which can possess bias to begin with. I had the unique opportunity to create naturalized populations of fish by seeding each of four small fishless lakes with equal densities of slow-, intermediate-, and fast-growing fish. Using sampling methods that are not size-selective, I observed that fast-growing fish were up to two-times more likely to be sampled than slower-growing fish. This indicates substantial and systematic bias with respect to an important life history trait (growth rate). If correlations between behavioral, physiological and life-history traits are as widespread as the literature suggests, then many animal samples may be systematically biased with respect to these traits (e.g., when collecting animals for laboratory use), and affect our inferences about population structure and abundance. I conclude with a discussion on ways to minimize sampling bias for particular physiological/behavioral/life-history types within animal populations.