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
The birth of a new protein
20.10.2017 | University of Arizona
Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research