Random walk in genome space: A key ingredient of intermittent dynamics of community assembly on evolutionary time scales


Murase, Yohsuke
Shimada, Takashi
Ito, Nobuyasu
Rikvold, Per Arne

KAUST Grant Number


Community assembly is studied using individual-based multispecies models. The models have stochastic population dynamics with mutation, migration, and extinction of species. Mutants appear as a result of mutation of the resident species, while migrants have no correlation with the resident species. It is found that the dynamics of community assembly with mutations are quite different from the case with migrations. In contrast to mutation models, which show intermittent dynamics of quasi-steady states interrupted by sudden reorganizations of the community, migration models show smooth and gradual renewal of the community. As a consequence, instead of the 1/f diversity fluctuations found for the mutation models, 1/f2, random-walk like fluctuations are observed for the migration models. In addition, a characteristic species-lifetime distribution is found: a power law that is cut off by a "skewed" distribution in the long-lifetime regime. The latter has a longer tail than a simple exponential function, which indicates an age-dependent species-mortality function. Since this characteristic profile has been observed, both in fossil data and in several other mathematical models, we conclude that it is a universal feature of macroevolution. © 2010 Elsevier Ltd.

Murase Y, Shimada T, Ito N, Rikvold PA (2010) Random walk in genome space: A key ingredient of intermittent dynamics of community assembly on evolutionary time scales. Journal of Theoretical Biology 264: 663–672. Available: http://dx.doi.org/10.1016/j.jtbi.2010.03.043.

We are grateful for helpful comments on the manuscript by A.G. Rossberg, V. Sevim, and E. Filotas, and for a useful conversation with L.H. Liow. This work was partly supported by 21st Century COE Program "Applied Physics on Strong Correlation" from the Ministry of Education, Culture, Sports, Science, and Technology of Japan, the JSPS (No. 19340110), and GRP of KAUST (KUK-I1-005-04), and a Grant-in-Aid for Young Scientists (B) No. 21740284 to T. S. from the Ministry of Education, Culture, Sports, Science and Technology of Japan. Y.M. appreciates hospitality at Florida State University, where work was supported by U.S. NSF Grant Nos. DMR-0444051 and DMR-0802288.

Elsevier BV

Journal of Theoretical Biology


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