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Biomedical subjects

Kevin N Laland

Publications and source records attributed to Kevin N Laland.

8 recordsLinked to original sources

Nine-spined sticklebacks exploit the most reliable source when public and private information conflict.

Social foragers can potentially use private information gained from personal experience and public information gained from observing the foraging success of others to determine the profitability of a foraging patch. We investigated how nine-spined sticklebacks use conflicting public and private information of variable reliability to make foraging decisions. In a first experiment, when private information was reliable, sticklebacks ignored public information and based their foraging decision on private information. However, when private information was less reliable, sticklebacks tended to use public rather than private information. A second experiment investigated how the time since experiencing private information affected sticklebacks' use of this information when it conflicted with recent public information. Fish based their foraging decisions on recently acquired private information, but reliance on private information diminished as the period since experiencing it increased. Fish used public information if 7 days had elapsed since updating their private information. Our findings suggest that nine-spined sticklebacks flexibly adjust their decision making to exploit the most reliable information available, be it public or private, and that animals will weight private and public information appropriately depending on circumstances.

Animals↗

Perspective: is human cultural evolution Darwinian? Evidence reviewed from the perspective of the Origin of Species.

The claim that human culture evolves through the differential adoption of cultural variants, in a manner analogous to the evolution of biological species, has been greeted with much resistance and confusion. Here we demonstrate that as compelling a case can now be made that cultural evolution has key Darwinian properties, as Darwin himself presented for biological evolution in The Origin of Species. Culture is shown to exhibit variation, competition, inheritance, and the accumulation of successive cultural modifications over time. Adaptation, convergence, and the loss or change of function can also be identified in culture. Just as Darwin knew nothing of genes or particulate inheritance, a case for Darwinian cultural evolution can be made irrespective of whether unitary cultural replicators exist or whether cultural transmission mechanisms are well understood.

Adaptation, Biological↗

Social learning strategies.

In most studies of social learning in animals, no attempt has been made to examine the nature of the strategy adopted by animals when they copy others. Researchers have expended considerable effort in exploring the psychological processes that underlie social learning and amassed extensive data banks recording purported social learning in the field, but the contexts under which animals copy others remain unexplored. Yet, theoretical models used to investigate the adaptive advantages of social learning lead to the conclusion that social learning cannot be indiscriminate and that individuals should adopt strategies that dictate the circumstances under which they copy others and from whom they learn. In this article, I discuss a number of possible strategies that are predicted by theoretical analyses, including copy when uncertain, copy the majority, and copy if better, and consider the empirical evidence in support of each, drawing from both the animal and human social learning literature. Reliance on social learning strategies may be organized hierarchically, their being employed by animals when unlearned and asocially learned strategies prove ineffective but before animals take recourse in innovation.

Adaptation, Psychological↗

Species difference in adaptive use of public information in sticklebacks.

Animals foraging on variable food sources can refine their estimates of patch quality by monitoring the success of others (i.e. collect 'public information'). Here, we show that both three-spined sticklebacks (Gasterosteus aculeatus) and nine-spined sticklebacks (Pungitius pungitius) use past cues provided by others to locate food but only nine-spined sticklebacks use prior public information to assess patch quality, regardless of whether demonstrators were conspecifics or heterospecifics. Moreover, nine-spined but not three-spined sticklebacks preferentially hid in vegetation during the demonstration, a position from which they could observe both patches simultaneously and collect public information. We conclude that species differences in the use of public information can be explained by variations in habitat choice and response to predation. Our findings expand current understanding of the scope of public-information use in animals by showing that fishes can use public-information in a foraging context and from heterospecifics. The study suggests that public-information use is an adaptation that allows animals vulnerable to predation to acquire valuable foraging information at low risk.

Adaptation, Biological↗

Rethinking adaptation: the niche-construction perspective.

Niche construction refers to the capacity of organisms to construct, modify, and select important components of their local environments, such as nests, burrows, pupal cases, chemicals, and nutrients. A small but increasing number of evolutionary biologists regard niche construction as an evolutionary process in its own right, rather than as a mere product of natural selection. Through niche construction organisms not only influence the nature of their world, but also in part determine the selection pressures to which they and their descendants are exposed, and they do so in a non-random manner. Mathematical population genetics analyses have revealed that niche construction is likely to be evolutionarily consequential because of the feedback that it generates in the evolutionary process. A parallel movement has emerged in ecosystem ecology, where researchers stress the utility of regarding organisms as ecosystem engineers, who partly control energy and matter flows. From the niche construction standpoint, the evolving complementary match between organisms and environments is the product of reciprocal interacting processes of natural selection and niche construction. This essay reviews the arguments put forward in favor of the niche-construction perspective.

Adaptation, Biological↗

Social intelligence, innovation, and enhanced brain size in primates.

Despite considerable current interest in the evolution of intelligence, the intuitively appealing notion that brain volume and "intelligence" are linked remains untested. Here, we use ecologically relevant measures of cognitive ability, the reported incidence of behavioral innovation, social learning, and tool use, to show that brain size and cognitive capacity are indeed correlated. A comparative analysis of 533 instances of innovation, 445 observations of social learning, and 607 episodes of tool use established that social learning, innovation, and tool use frequencies are positively correlated with species' relative and absolute "executive" brain volumes, after controlling for phylogeny and research effort. Moreover, innovation and social learning frequencies covary across species, in conflict with the view that there is an evolutionary tradeoff between reliance on individual experience and social cues. These findings provide an empirical link between behavioral innovation, social learning capacities, and brain size in mammals. The ability to learn from others, invent new behaviors, and use tools may have played pivotal roles in primate brain evolution.

Animals↗