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
How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH
A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
23.06.2017 | Physics and Astronomy
23.06.2017 | Physics and Astronomy
23.06.2017 | Information Technology