Physics and math shed new light on biology by mapping the landscape of evolution

Aug 08, 2012

Researchers capture evolutionary dynamics in a new theoretical framework that could help explain some of the mysteries of how and why species change over time.

Although the qualitative description of evolution – its observed behavior and characteristics – is well-established, a comprehensive quantitative theory that captures general evolution dynamics is still lacking. There are also many lingering mysteries surrounding the story of life on Earth, including the question of why sex is such a prevalent reproductive strategy. A team of scientists from the Chinese Academy of Sciences; Jilin University in Jilin, China; and the State University of New York at Stony Brook, led by Prof. Jin Wang, has examined some of these puzzles from a physical science prospective. They propose a new theory of evolution with two ingredients: the underlying emergent "fitness" landscape and an associated evolutionary force called "curl flux," which causes species to move through the emergent fitness landscape in a spiraling manner.

The researchers captured evolutionary relationships in a system of equations. They then created quantitative pictures that visualized evolutionary pathways as journeys through a mountainous terrain of peaks and valleys of biological fitness. The key breakthrough beyond the conventional quantitative theory of evolution is the emergent curl flux, which is generated by interactions between individuals within or across species. The underlying emergent landscape gradient and the curl flux act together as a "Yin and Yang" duality pair to determine the dynamics of general evolution, says Wang. An example of similar behavior is the particle and wave duality that determines the dynamics of the quantum world, he notes. The researchers also note that this combined effect is analogous to the way electric and magnetic forces both act on electrons.

The new theory provides a physical foundation for general evolution dynamics. The researchers found that interactions between individuals of different species can give rise to the curl flux. This can sustain an endless evolution that does not lead to areas of higher relative fitness, even if the physical environment is unchanged.

This finding offers a to explain the Red Queen Hypothesis, which states that species continually evolve in order to fend off parasites that are themselves continually evolving. The hypothesis, first proposed by evolutionary biologist Leigh Van Valen in 1973, gets its name from the character of the Red Queen in Lewis Carroll's book Through the Looking-Glass, who observed that in her world it was necessary to keep running just to stay in one place. The idea of endless co- through the maintenance of the genetic variation due to the curl flux could help explain the benefits of sexual reproduction, since the mixing and matching of genes preserves a greater diversity of traits. When a species' arms race with a co-evolving parasite takes an unexpected twist, a previously unnecessary trait could suddenly turn into the key to surviving. In the co-evolving world, there is no guarantee for "survival of the fittest" and it is often necessary to keep running for survival.

The researchers publish their results in the American Institute of Physics' Journal of Chemical Physics.

Explore further: Driving cancer cells to suicide

More information: "The potential and flux landscape theory of evolution" is accepted for publication in The Journal of Chemical Physics. jcp.aip.org/resource/1/jcpsa6/v137/i6/p065102_s1

Related Stories

Scientists reveal driving force behind evolution

Feb 25, 2010

Scientists at the University of Liverpool have provided the first experimental evidence that shows that evolution is driven most powerfully by interactions between species, rather than adaptation to the environment.

Interacting mutations promote diversity

Jun 28, 2012

Genetic diversity arises through the interplay of mutation, selection and genetic drift. In most scientific models, mutants have a fitness value which remains constant throughout. Based on this value, they compete with other ...

Recommended for you

The origins of handedness in life

6 hours ago

Handedness is a complicated business. To simply say life is left-handed doesn't even begin to capture the blooming hierarchy of binary refinements it continues to evolve. Over the years there have been numerous ...

Driving cancer cells to suicide

Sep 30, 2014

Ludwig Maximilian University of Munich researchers report that a new class of chemical compounds makes cancer cells more sensitive to chemotherapeutic drugs. They have also pinpointed the relevant target ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

antonima
not rated yet Aug 14, 2012
[QUOTE]There are also many lingering mysteries surrounding the story of life on Earth, including the question of why sex is such a prevalent reproductive strategy.[/QUOTE]

It is a means of genetic recombination to increase genetic diversity and eliminate negative mutations that appear parallel to beneficial mutations. When a helpful mutation occurs in an organism that has one or more harmful mutations then there is no net benefit to the organism. Because sex allows genetic recombination, it is then possible for the offspring to obtain the helpful mutation from one parent without obtaining the harmful.. . every biology course explains this, this isn't even college stuff.