Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

European evolutionary biologists rally behind Richard Dawkins' Extended Phenotype

19.01.2009
Richard Dawkins' Extended Phenotype (EP) concept is as relevant now as when it was first proposed 26 years ago and is not at odds with other evolutionary explanations. This was the conclusion of a recent workshop on the Extended Phenotype today, organized by the European Science Foundation (ESF).

The EP states that the genes of an organism can be expressed beyond its immediate biological boundary, extending for example to birds' nests, or the behaviour of hosts infected by parasites.

The key point is that the EP embraces constructions, such as the dams built by beavers, whose quality is correlated with variations, or alleles, in certain of the organism's genes, so that natural selection can act upon them. A new allele that leads to better dam constructions will in turn benefit the beaver expressing it. Similarly a parasite allele that causes the behaviour of its host to change in a way that increases the parasite's chance of survival will be favoured.

Dawkins regarded EP as his single most important contribution to evolutionary biology, but since its publication in 1982, other theories have emerged and questions have arisen over its own fitness for survival. Any doubts were dispelled at the ESF conference, which resurrected EP as an important and valuable concept that helps explain evolution, even though it does not actually help predict specific outcomes.

"It was recognised that it has explanatory rather than predictive power," said David Hughes, convenor of the ESF workshop, from the Department of Biology, University of Copenhagen, now at Harvard. "It is a good way of looking at things but not necessarily the best approach when designing experiments."

The idea that niche construction, often considered as a rival theory, contradicted EP was dismissed. "It was agreed that other currently topical points of debate such as Niche Construction theory had no major conflict with the EP," said Hughes.

However there was lively debate between Dawkins and proponents of niche construction over the role of evolution within closely coupled ecosystems. Niche construction theory goes further than EP by suggesting that organisms can alter the selective pressures acting on them by modifying their environment in many ways beyond immediate constructions such as beaver dams. In niche construction theory, the link between variations in an organism's genes and in the surrounding environment is more loosely coupled with no clear mechanism for natural selection to operate.

However according to niche construction theory, there is a feedback effect, in that the genes of organisms alter the environment indirectly, for example by improving nests, that in turn modifies the selective pressures on those genes. Dawkins argued that niche construction is really a special case of EP, relating to genes of those organisms that participate in the relevant environmental construction. But he dismissed the idea that evolution can act in a broader sense across a whole ecosystem, extending to organisms not directly involved in the niche construction. He reiterated the point running through all his books, that selection can only operate against variation of replicators, which are almost always alleles (variants) of genes. The variation in genes caused by mutation generates the different phenotypes, characteristics such as animal behaviour, that allow natural selection to work.

Some advocates of niche construction have suggested that evolution can operate at longer range. For example beavers construct dams that might benefit other animals not directly associated with them. While this may be the case, Dawkins has consistently argued that this would not result in behaviour that would help select genes in beavers themselves that would lead to better dams. Only organisms whose response to better dams has a direct benefit for beavers can affect selection of beaver genes, Dawkins argues.

These points were accepted at the ESF workshop, which concluded that the EP was fine as it stood with no need of revision. Moreover, it emerged that recent research on metabolism had reinforced the EP concept, in particular by showing how closely the health of mammals including humans depends on the populations of microbes, especially bacteria, in the gut. EP might help understand how these populations have evolved in concert with mammals.

Ideas for further projects were proposed. "A follow up funding application is a great idea and it should focus on examining the parasite manipulation of host behaviour component," said Hughes. "There was also a suggestion to have a separate application for a nest construction pan-EU network." These programs would be truly European, typically involving 5-7 partners across the EU.

The ESF Explanatory Workshop, The New Role of the Extended Phenotype in Evolutionary Biology, was held in Copenhagen, Denmark, 2-5 November 2008.

Thomas Lau | alfa
Further information:
http://www.esf.org
http://www.esf.org/activities/exploratory-workshops/workshops-list/workshops-detail.html?ew=6586

More articles from Life Sciences:

nachricht Newly designed molecule binds nitrogen
23.02.2018 | Julius-Maximilians-Universität Würzburg

nachricht Atomic Design by Water
23.02.2018 | Max-Planck-Institut für Eisenforschung GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>