Capturing the many facets of evolvability

Date:
March 2, 2022
Source:
University of Groningen
Summary:
All life evolves: microorganisms can become resistant to drugs,
viruses evade our vaccines, and species may adapt to climate
change. Even the ability to evolve can evolve. If we were to
understand how this happens and which mechanisms play a role,
it may be possible to predict evolution to some extent.



FULL STORY ==========================================================================
All life evolves: microorganisms can become resistant to drugs, viruses
evade our vaccines, and species may adapt to climate change. Even the
ability to evolve can evolve. If we were to understand how this happens
and which mechanisms play a role, it may be possible to predict evolution
to some extent.

This is why the concept of evolvability is now very popular in various
areas of the life sciences. However, it turns out that this concept is
used in very different ways within the scientific community. Theoretical biologists from the University of Groningen have now written a paper
that should create some order in discussions on evolvability. It was
published online in Trends in Ecology and Evolution on 10 February.


==========================================================================
It all started with a journal club, organized by three PhD students in evolutionary biology. They could not always agree on whether a paper
under discussion was really about evolvability and eventually realized
that this could be due to their different backgrounds: the emergence
of antibiotic resistance, the evolution of gene networks, and the
evolution of vertebrates living in social systems. 'The confusion that
we experienced is also reflected in the literature,' says Jana Riederer,
joint first author of the paper together with journal club members Stefano
Tiso and Timo van Eldijk. 'We wanted to sort this out for ourselves at
first,' she continues. 'But then we thought that it might be useful to
others too.' Timescale The result of their discussions is a paper that describes different facets of evolvability. 'We identified three types
of mechanisms underlying evolvability,' explains Van Eldijk. These are determinants providing variation, determinants shaping the effect of
variation on fitness, and determinants shaping the selection process.

Furthermore, evolvability depends on the timescale. Pathogens, such as
bacteria or viruses, often reproduce asexually by cloning themselves,
while many hosts, such as humans, reproduce sexually. Therefore,
questions regarding the arms race between hosts and pathogens are
closely related to a longstanding debate in evolutionary biology:
which type of reproduction facilitates evolution best? Riederer:
'We concluded that they each work best at their own time scale.'
Sexual reproduction Asexually reproducing organisms evolve fast,
which is better in the short term but they typically do not reach the
highest level of adaptation. In contrast, sexual reproduction slows down evolution but allows for a more thorough exploration of all options and,
in the long-term, achieves a higher level of adaptation. Van Eldijk: 'Evolutionary scientists often choose an endpoint for their studies and
will, for example, look at which bacterial strain is best adapted after
a hundred generations. But they might get a different outcome if their experiment were to continue for a thousand generations.' A final aspect
of evolvability is a difference in scope: some mechanisms work for many different environments, for example an increased mutation rate.

Others, such as the presence of a specific enzyme that could evolve
to confer resistance to a particular antibiotic, are limited in their
scope. But both mechanisms can help to shape evolvability.

Influence In conclusion, the three PhD students, who wrote the paper
together with their supervisor Professor Franjo Weissing, identified many different facets of evolvability. Tiso: 'We had a lot of discussions;
it took us about two years.

We had to consider many points that are outside our different
disciplines.' Their hope is that this paper will stimulate
communication between evolutionary biologists and perhaps lead to
practical applications. After all, once the mechanisms of evolvability
are clearer, it may become possible to better predict the course of
evolution. 'In a probabilistic manner, of course,' adds Van Eldijk. 'But
if we understand the mechanism by which an organism adapts, it will
perhaps become possible to influence this process,' Tiso agrees.

The framework that is described in the paper lays down clear
recommendations for future research and can clarify discourse on
evolvability. The authors conclude that this may help to resolve long
standing discrepancies and debates in the field of evolutionary biology.

========================================================================== Story Source: Materials provided by University_of_Groningen. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Jana M. Riederer, Stefano Tiso, Timo J.B. van Eldijk, Franz
J. Weissing.

Capturing the facets of evolvability in a mechanistic
framework. Trends in Ecology & Evolution, 2022; DOI:
10.1016/j.tree.2022.01.004 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/03/220302113053.htm

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