Researchers believe they have solved a mystery that has puzzled evolutionary scientists for years ... if 'good' genes spread through the population, why are individuals so different?
The so-called 'lek paradox', that sexually-selecting species like humans should have much less individuality than is the case, has been seized upon by creationists as an argument that Darwin's theories are fundamentally flawed.
The problem with current evolutionary theory is that if females select the most attractive mates, the genes responsible for attractive features should spread quickly through a population, resulting in males becoming equally attractive, to the point where sexual selection could no longer take place.
However, new research by Professor Marion Petrie and Dr Gilbert Roberts at Newcastle University, England, suggests that sexual selection can in fact cause greater genetic diversity by a mechanism not previously understood.
Professor Petrie theorised that since genetic mutations can occur anywhere in the genome, some will affect the 'DNA repair kit' possessed by all cells. As a result, some individuals have less efficient repair kits, resulting in greater variation in their DNA as damage does unrepaired.
Although unrepaired DNA is generally harmful - causing tissue to degenerate or develop cancers - it is useful in some parts of the genome, such as those parts resposible for disease defence where variation can help in the resistance to disease. It has long been known that greater variation of DNA in the disease defending regions makes it more likely that an individual can resist attacks by bacteria and viruses.
Using a computer model to map the spread of genes in a population, Professor Petrie demonstrated that the tendency towards reduction in genetic diversity caused by sexual selection is outweighed by the maintenance in greater genetic diversity generated by mutations affecting DNA repair.
The research is published today (28 March 2007) in the academic journal, Heredity, part of the Nature Publishing Group.
Professor Petrie, of the Evolution and Behaviour Research Group in the School of Biology at Newcastle University, said: 'We started this research ten years ago and our model has now produced a good fit with what we observe in terms of genetic variation, which leads us to believe that our theory is correct.' 'We find that sexual selection can promote genetic diversity despite expectations to the contrary.'
In 2005, Professor Petrie and colleagues demonstrated that men with greater genetic diversity in disease defence regions of the genome — and therefore better prospects of passing disease resistance to their offspring — had a number of physical features which women found attractive. The research involved testing men for genetic diversity and showing photographs of them to women, who allocated scores for attractiveness. These scores were found to correlate strongly to genetic diversity.
Marion Petrie | EurekAlert!
Newly discovered bacteria-binding protein in the intestine
08.12.2016 | University of Gothenburg
The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Materials Sciences
08.12.2016 | Materials Sciences
08.12.2016 | Physics and Astronomy