To sleep or not to sleep: the ecology of sleep in artificial organisms.
To sleep or not to sleep: the ecology of sleep in artificial organisms.
复制标题
DOI：
10.1186/1472-6785-8-10
复制
发表时间：
2008-05-14
期刊：
影响因子：
--
通讯作者：
Nunn CL
中科院分区：
文献类型：
--
作者：
Acerbi A;McNamara P;Nunn CL
到目前为止，所有动物都研究了睡眠，但对产生物种间睡眠特征差异的生态因素知之甚少，例如总睡眠时间或在24小时内将睡眠分为多次发作（即，单相或多相睡眠活动）。在这里，我们解决这些问题，使用一个进化的基于代理的模型。该模型在空间上是明确的，食物和睡眠的网站分布在两个集群的景观。代理人根据内部生物钟获得食物和睡眠能量，该生物钟由24种特征编码（一天中的每一个小时），这些特征对应于通过遗传算法进化的“基因”。这些特征可以假设三个不同的值来指定智能体的行为：睡眠（或搜索睡眠站点），进食（或搜索食物站点），或者基于睡眠能量和食物能量的相对水平灵活地决定行动。具有较高适应度分数的个体在下一代模拟中留下更多的后代，因此该模型可以用于识别不同生态条件下的进化适应性生物钟参数。我们系统地改变了与食物和睡眠部位的数量、食物和睡眠部位重叠的程度以及食物斑块耗尽的速率有关的输入参数。我们的研究结果表明：（1）在空间上更分离的食物和睡眠集群之间旅行的增加的成本选择了双相睡眠，（2）更快的食物块耗尽减少了睡眠时间，以及（3）代理花费更多的时间试图获取“更稀有”的资源，也就是说，花费在睡眠上的平均时间与食物块的数量正相关，与睡眠块的数量负相关。一般来说，“灵活”基因似乎并不具有优势，尽管它们在代理基因组中的排列显示出特征模式，表明选择对其分布起作用。总的来说，结果表明生态因素对睡眠模式有显著影响。此外，我们的研究结果表明，一个简单的模型可以产生清晰和合理的模式，从而使其能够用于调查有关睡眠生态学的广泛问题。定量数据目前无法直接测试模型的预测，但模式是一致的，从不同物种的比较证据，该模型可以用来针对生态因子进行调查，在未来的研究。
All animals thus far studied sleep, but little is known about the ecological factors that generate differences in sleep characteristics across species, such as total sleep duration or division of sleep into multiple bouts across the 24-hour period (i.e., monophasic or polyphasic sleep activity). Here we address these questions using an evolutionary agent-based model. The model is spatially explicit, with food and sleep sites distributed in two clusters on the landscape. Agents acquire food and sleep energy based on an internal circadian clock coded by 24 traits (one for each hour of the day) that correspond to "genes" that evolve by means of a genetic algorithm. These traits can assume three different values that specify the agents' behavior: sleep (or search for a sleep site), eat (or search for a food site), or flexibly decide action based on relative levels of sleep energy and food energy. Individuals with higher fitness scores leave more offspring in the next generation of the simulation, and the model can therefore be used to identify evolutionarily adaptive circadian clock parameters under different ecological conditions. We systematically varied input parameters related to the number of food and sleep sites, the degree to which food and sleep sites overlap, and the rate at which food patches were depleted. Our results reveal that: (1) the increased costs of traveling between more spatially separated food and sleep clusters select for monophasic sleep, (2) more rapid food patch depletion reduces sleep times, and (3) agents spend more time attempting to acquire the "rarer" resource, that is, the average time spent sleeping is positively correlated with the number of food patches and negatively correlated with the number of sleep patches. "Flexible" genes, in general, do not appear to be advantageous, though their arrangements in the agents' genome show characteristic patterns that suggest that selection acts on their distribution. Collectively, the output suggests that ecological factors can have striking effects on sleep patterns. Moreover, our results demonstrate that a simple model can produce clear and sensible patterns, thus allowing it to be used to investigate a wide range of questions concerning the ecology of sleep. Quantitative data presently are unavailable to test the model predictions directly, but patterns are consistent with comparative evidence from different species, and the model can be used to target ecological factors to investigate in future research.
登录
查看更多内容
影响因子：
4.4
作者：
Affanni, JM;Cervino, CO;Marcos, HJA
通讯作者：
Marcos, HJA
影响因子：
2.5
作者：
ELGAR, MA;PAGEL, MD;HARVEY, PH
通讯作者：
HARVEY, PH
影响因子：
2.5
作者：
Lima, Steven L.;Rattenborg, Niels C.
通讯作者：
Rattenborg, Niels C.
影响因子：
11.4
作者：
Seymour, JE;Carrette, TJ;Sutherland, PA
通讯作者：
Sutherland, PA
影响因子：
3.1
作者：
Grimm, Volker;Berger, Uta;DeAngelis, Donald L.
通讯作者：
DeAngelis, Donald L.