| Autor: |
Isaksson H; Department of Mathematics and Mathematical Statistics, Umeå University, 90187 Umeå, Sweden.; Integrated Science Lab, Umeå University, 90187 Umeå, Sweden., Conlin PL; Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA 30332, USA., Kerr B; Department of Biology, BEACON Center for the Study of Evolution in Action, University of Washington, Seattle, WA 98195, USA., Ratcliff WC; Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA 30332, USA., Libby E; Department of Mathematics and Mathematical Statistics, Umeå University, 90187 Umeå, Sweden.; Integrated Science Lab, Umeå University, 90187 Umeå, Sweden.; Santa Fe Institute, Santa Fe, NM 87501, USA. |
| Abstrakt: |
Early multicellular organisms must gain adaptations to outcompete their unicellular ancestors, as well as other multicellular lineages. The tempo and mode of multicellular adaptation is influenced by many factors including the traits of individual cells. We consider how a fundamental aspect of cells, whether they reproduce via binary fission or budding, can affect the rate of adaptation in primitive multicellularity. We use mathematical models to study the spread of beneficial, growth rate mutations in unicellular populations and populations of multicellular filaments reproducing via binary fission or budding. Comparing populations once they reach carrying capacity, we find that the spread of mutations in multicellular budding populations is qualitatively distinct from the other populations and in general slower. Since budding and binary fission distribute age-accumulated damage differently, we consider the effects of cellular senescence. When growth rate decreases with cell age, we find that beneficial mutations can spread significantly faster in a multicellular budding population than its corresponding unicellular population or a population reproducing via binary fission. Our results demonstrate that basic aspects of the cell cycle can give rise to different rates of adaptation in multicellular organisms. |
