Evolution of irreversible somatic differentiation

Pichugin

2022

eLife

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The evolution of multicellular life cycles is a central process in the course of the emergence of multicellularity. The simplest multicellular life cycle is comprised of the growth of the propagule into a colony and its fragmentation to give rise to new propagules. The majority of theoretical models assume selection among life cycles to be driven by internal properties of multicellular groups, resulting in growth competition. At the same time, the influence of interactions between groups on the evolution of life cycles is rarely even considered. Here, we present a model of colonial life cycle evolution taking into account group interactions. Our work shows that the outcome of evolution could be coexistence between multiple life cycles or that the outcome may depend on the initial state of the population – scenarios impossible without group interactions. At the same time, we found that some results of these simpler models remain relevant: evolutionary stable strategies in our model are restricted to binary fragmentation – the same class of life cycles that contains all evolutionarily optimal life cycles in the model without interactions. Our results demonstrate that while models neglecting interactions can capture short-term dynamics, they fall short in predicting the population-scale picture of evolution.

Section: Introductionmentioning

confidence: 99%

Eco-evolutionary dynamics of clonal multicellular life cycles

Ress

Pichugin

2022

eLife

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“…Colonies are born small but due to cell divisions they increase in size and, eventually, fragment, so the number of colonies in the population grows. The life cycle maximizing the population growth rate has a selective advantage, as it outgrows all competitors [Roze et al, 2001, Libby et al, 2014, Pichugin et al, 2017, 2019, Staps et al, 2019, Gao et al, 2019, Pichugin and Traulsen, 2020, Gao et al, 2021, Pichugin and Traulsen, 2022]. It was shown that for groups made of identical cells, some life cycles are forbidden: they cannot be the winner of growth competition under any conditions.…”

Section: Introductionmentioning

confidence: 99%

Eco-evolutionary dynamics of clonal multicellular life cycles

Ress

Pichugin

2022

Preprint

Self Cite

The evolution of multicellular life cycles is a central process in the course of the emergence of multicellularity. The simplest multicellular life cycle is comprised of the growth of the propagule into a colony and its fragmentation to give rise to new propagules. The majority of theoretical models assume selection among life cycles to be driven by internal properties of multicellular groups resulting in growth competition. At the same time, the influence of interactions between groups on the evolution of life cycles is rarely even considered. Here, we present a model of colonial life cycles evolution taking into account group interactions. Our work shows that the outcome of evolution could be coexistence between multiple life cycles or that the outcome may depend on the initial state of the population -- scenarios impossible without group interactions. At the same time, we found that some results of these simpler models remain relevant: Evolutionary stable strategies in our model are restricted to binary fragmentation -- the same class of life cycles which contains all evolutionarily optimal life cycles in the model without interactions. Our results demonstrate that while models neglecting interactions can capture short-term dynamics, they fall short in predicting the population-scale picture of the evolution.

Evolution of irreversible differentiation under stage-dependent cell differentiation

Gao

Zapién-Campos

2023

Preprint

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The specialization of cells is a hallmark of complex multicellularity. Cell differentiation enables the emergence of specialized cell types that carry out segregated functions which are previously executed by a multifunctional ancestor cell. Yet, it is still unclear why cell differentiation evolved in the first place, especially for genetically identical cells, exposed to the same life history environment. Stochasticity in gene expression has been proposed to account for cell differentiation. We develop a theoretical model to investigate the effect of dynamic cell differentiation — cells can change their developmental trajectories during a single round of development — on the evolution of their cell differentiation strategy. We found that in small organisms, irreversible differentiation – a cell type gradually losing its cell differentiation capability to produce other cell types – classified based on the differentiation capability at the last cell division, is favoured over other differentiation strategies under dynamic cell differentiation. Dynamic cell differentiation allows a wide range of differentiation strategies, allowing more evolutionary possibilities than static cell differentiation.