Evolution and ecological competition of multicellular life cycles

Volvox’s daughter colonies within the Volvox mother colony. Credit: Frank Fox

New studies by the Max Planck Institute for Evolutionary Biology show that competition between different evolutionary stages of multicellular life cycles can be important for the development of an entire population. Without direct competition, only the rate of population growth determines the prevailing life cycle.

Environmental competition, on the other hand, can lead to a completely different choice life cycles.

has evolved multicellular organisms It is a central process in the Origin of Life Pathway. In most cases, an organism is multicellular for only part of its life cycle: the simplest multicellular life cycle consists of the growth of a germ cell into a colony and its division into single cells To produce new germ cells.

So far, most theoretical models He hypothesizes that the choice between life cycles is driven by the internal characteristics of multicellular groups, leading to growth competition. At the same time, the influence of interactions between groups on the development of life cycles is rarely taken into account.

Vanessa Reis (University of Hamburg), Arne Traulsen (Max Planck Institute for Evolutionary Biology, Plon) and Yuri Bichogen (Princeton University, USA) now present a new model that takes into account the ecological competition between individual life cycles – a project initiated by Vanessa Reis’s master’s thesis under the supervision of Dr. Bichogen.

The model shows that the result of evolution can be a symbiosis of several life cycles, which would be impossible without competition. Similarly, the research shows that models that neglect this competition can capture short-term dynamics but fail to predict evolution at the population level.

Multicellular organisms such as animals, plants, fungi or red and brown algae are often formed by their cells remaining together after cell division—Unlike unicellular types where cells separate before the next division. However, living things must reproduce, or else their species will become extinct. For a multicellular organism, this means that some cells must migrate to develop into a new individual.

The combination of growth and reproduction of an organism forms clonal life cycle. The emergence of clonal multicellular life cycles was the central innovation in the early stages of multicellular development. There, characteristics not found at all in unicellular species become crucial to the long-term success of even the most primitive cell colonies. This includes the number of cells in the colony, the frequency of cell migration to form new colonies, the size of germ cells released and the number of germ cells produced.

Since reproduction, and thus the suitability of simple cell colonies, depends on these characteristics, they are immediately subject to them natural selectionwhich favors some life cycles over others.

Since complex multicellular life descends from these simple cell colonies, understanding the evolution of primitive life cycles is critical to understanding the evolution of complex organisms.

The search was published in eLife.

more information:
Vanessa Rees et al., Dynamics of Ecological Evolution of Multiclonal Life Cycles, eLife (2022). DOI: 10.7554 / eLife.78822

Journal information:

Introduction of
Max Planck Society

the quote: Evolution and Environmental Competition for Multicellular Life Cycles (2022, September 14) Retrieved on September 14, 2022 from

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