Hasil untuk "Evolution"

J. Sheth, Atul Parvatiyar

Jennifer F. Reinganum

S. D. Durrant, G. Simpson

D. Soltis, P. Soltis

H. Selye

J. Henrich, R. Mcelreath

A. Becker, G. Theißen

A. Norenzayan, A. Shariff

J. Ostriker, O. Gnedin

Günter P. Wagner, L. Altenberg

M. Jackson, A. Watts

R. Sage

T. Embley, W. Martin

N. Kashtan, U. Alon

A. Traulsen, M. Nowak

We propose a minimalist stochastic model of multilevel (or group) selection. A population is subdivided into groups. Individuals interact with other members of the group in an evolutionary game that determines their fitness. Individuals reproduce, and offspring are added to the same group. If a group reaches a certain size, it can split into two. Faster reproducing individuals lead to larger groups that split more often. In our model, higher-level selection emerges as a byproduct of individual reproduction and population structure. We derive a fundamental condition for the evolution of cooperation by group selection: if b/c > 1 + n/m, then group selection favors cooperation. The parameters b and c denote the benefit and cost of the altruistic act, whereas n and m denote the maximum group size and the number of groups. The model can be extended to more than two levels of selection and to include migration.

Eugene Berezikov

L. Yates, P. Campbell

C. Strömberg

Arnaud Martin, V. Orgogozo

Bastien Mallein, Francesco Paparella, Emmanuel Schertzer et al.

Biological evolution depends on the passing down to subsequent generations of genetic information encoding beneficial traits, and on the removal of unfit individuals by a selection mechanism. However, selection acts on phenotypes, and is affected by random contingencies. Thus, a combination of fitness and luck determines which individuals will successfully reproduce and give rise to the next generation. To understand how randomness in the selection mechanism affects the long-term patterns of evolution, we studied an idealized evolution model. We show through simulations and mathematical analysis, that the speed of adaptation increases with increasing selection pressure only up to a threshold. Beyond the threshold, any increase of the selection pressure results in more weight given to random effects rather than on genetic fitness in determining which individuals will successfully reproduce. This severely reduces the speed of adaptation and the diversity in the gene pool. Our findings may be considered as a biological instance of Goodhart's law: "When a measure becomes a target, it ceases to be a good measure". Finally, we show that this intricate response of evolution to natural selection can be mathematically explained by a novel phase transition for pulled traveling waves.