Biomedical subjects

K N Laland

Publications and source records attributed to K N Laland.

7 recordsLinked to original sources

PubMed2005

Age differences in neophilia, exploration, and innovation in family groups of callitrichid monkeys.

The prevailing assumption in the primate literature is that young or juvenile primates are more innovative than adult individuals. This innovative tendency among the young is frequently thought to be a consequence, or side effect, of their increased rates of exploration and play. Conversely, Reader and Laland's [International Journal of Primatology 22:787-806, 2001] review of the primate innovation literature noted a greater reported incidence of innovation in adults than nonadults, which they interpreted as (in part) a reflection of the greater experience and competence of older individuals. Within callitrichids there is contradictory evidence for age differences in response to novel objects, foods, and foraging tasks. By presenting novel extractive foraging tasks to family groups of callitrichid monkeys in zoos, we examined, in a large sample, whether there are positive or negative relationships of age with neophilia, exploration, and innovation, and whether play or experience most facilitates innovation. The results indicate that exploration and innovation (but not neophilia) are positively correlated with age, perhaps reflecting adults' greater manipulative competence. To the extent that there was evidence for play in younger individuals, it did not appear to contribute to innovation. The implications of these findings for the fields of innovation and conservation through reintroduction are considered.

Age Factors↗

PubMed2000

Niche construction, biological evolution, and cultural change.

We propose a conceptual model that maps the causal pathways relating biological evolution to cultural change. It builds on conventional evolutionary theory by placing emphasis on the capacity of organisms to modify sources of natural selection in their environment (niche construction) and by broadening the evolutionary dynamic to incorporate ontogenetic and cultural processes. In this model, phenotypes have a much more active role in evolution than generally conceived. This sheds light on hominid evolution, on the evolution of culture, and on altruism and cooperation. Culture amplifies the capacity of human beings to modify sources of natural selection in their environments to the point where that capacity raises some new questions about the processes of human adaptation.

Adaptation, Physiological↗

PubMed1999

Evolutionary consequences of niche construction and their implications for ecology.

Organisms regularly modify local resource distributions, influencing both their ecosystems and the evolution of traits whose fitness depends on such alterable sources of natural selection in environments. We call these processes niche construction. We explore the evolutionary consequences of niche construction using a two-locus population genetic model, which extends earlier analyses by allowing resource distributions to be influenced both by niche construction and by independent processes of renewal and depletion. The analysis confirms that niche construction can be a potent evolutionary agent by generating selection that leads to the fixation of otherwise deleterious alleles, supporting stable polymorphisms where none are expected, eliminating what would otherwise be stable polymorphisms, and generating unusual evolutionary dynamics. Even small amounts of niche construction, or niche construction that only weakly affects resource dynamics, can significantly alter both ecological and evolutionary patterns.

Alleles↗

PubMed1995

A gene-culture model of human handedness.

A model of handedness incorporating both genetic and cultural processes is proposed, based on an evolutionary analysis, and maximum-likelihood estimates of its parameters are generated. This model has the characteristics that (i) no genetic variation underlies variation in handedness, and (ii) variation in handedness among humans is the result of a combination of cultural and developmental factors, but (iii) a genetic influence remains since handedness is a facultative trait. The model fits the data from 17 studies of handedness in families and 14 studies of handedness in monozygotic and dizygotic twins. This model has the additional advantages that it can explain why monozygotic and dizygotic twins and siblings have similar concordance rates, and no hypothetical selection regimes are required to explain the persistence of left handedness.

Biological Evolution↗

PubMed1994

Sexual selection with a culturally transmitted mating preference.

Culturally transmitted mating preferences may generate sexual selection in human and protocultural animal species if they influence the intensity of selection on genetically transmitted physical and behavioral traits. Haploid and diploid two-"locus" models of sexual selection are presented in which mating preferences are culturally transmitted, while traits are transmitted genetically. The models exhibit dynamics similar to those of conventional haploid models of sexual selection, generating neutrally stable curves of equilibrium trait and preference frequencies. A culturally transmitted preference that reaches a significant frequency through cultural drift, individual learning, or social transmission can drag a less viable trait to fixation, or non-zero frequencies. Simulations suggest that strong biases in the transmission of preferences could take initially rare, less viable traits to fixation in as few as 20 to 50 generations, and weak biases in less than 100 generations. These conclusions hold for both biparental and maternally inherited mating preferences. Given the pervasiveness of cultural influences on human mate choice, the analysis suggests that this interaction may have played an important role in human evolution.

Animals↗

PubMed1994

Gene-culture coevolution and sex ratios: the effects of infanticide, sex-selective abortion, sex selection, and sex-biased parental investment on the evolution of sex ratios.

The evolutionary consequences of culturally transmitted practices that cause differential mortality between the sexes, thereby distorting the sex ratio (e.g., female infanticide and sex-selective abortion), are explored using dynamic models of gene-culture coevolution. We investigate how a preference for the sex of offspring may affect the selection of genes distorting the primary sex ratio. Sex-dependent differences in mortality have been predicted to select for a male- or female-biased primary sex ratio, to have no effect, or to favor either under different circumstances. We find that when a mating pair's behavior modifies mortality rates in favor of one sex, but does not change the number of offspring produced in the mating, the primary sex ratio will evolve a bias against the favored sex. However, when the total number of offspring of a mating pair is significantly reduced as a consequence of their prejudice, the primary sex ratio will evolve to favor the preferred sex. These results hold irrespective of whether the sex ratio is distorted by the mother's, the father's or the individual's own autosomal genes. The use of dynamic models of gene-culture coevolution allows us to explore the evolution of alleles which distort the sex ratio, as well as the final equilibrium states of the system. Gene-culture interactions can provide equilibria different from those in purely genetic systems, slow the approach to these equilibria by orders of magnitude, and move the primary (PSR) and the adult sex ratio (ASR) away from any stable equilibrium for hundreds of generations.

Abortion, Induced↗

PubMed1993

The mathematical modelling of human culture and its implications for psychology and the human sciences.

Recent years have seen the growth of a new and exciting field of theoretical research concerned with the mathematical modelling of human culture, and of its interaction with genetics. Drawing on analogies between genetic and cultural processes, mathematically sophisticated biologists have used population genetics models as the basis for the development of analogous models of cultural transmission, cultural evolution and gene-culture co-evolution. These models are designed to describe and analyse the diffusion of cultural traits through populations, under the influence of various cultural and evolutionary forces. They have already been applied to address many problems of interest to psychologists. Here I present an introduction to these models, explaining the mathematics in simple terms, and giving examples of the work of leading theorists. I go on to discuss the findings of most relevance to psychology, critically analysing the most important conclusions. Finally, I suggest some areas of psychology in which these models might usefully be applied. I argue that these models constitute a major theoretical innovation, and that there is considerable potential for their application in psychology.

Behavior↗