|Researchers have long assumed that factors like competition, environmental change and competition for scarce resources stimulated evolutionary change in species. But computer science researchers now say that the popular explanation of competition to survive in nature may not actually be necessary for evolvability to increase.|
Using a simulated model they designed to mimic how organisms evolve, the researchers saw increasing evolvability even without competitive pressure.
"The explanation is that evolvable organisms separate themselves naturally from less evolvable organisms over time simply by becoming increasingly diverse," said Kenneth O. Stanley, an associate professor at the College of Engineering and Computer Science at the University of Central Florida.
The finding could have implications for the origins of evolvability in many species.
"When new species appear in the future, they are most likely descendants of those that were evolvable in the past," Lehman said. "The result is that evolvable species accumulate over time even without selective pressure."
During the simulations, the team's simulated organisms became more evolvable without any pressure from other organisms out-competing them. The simulations were based on a conceptual algorithm.
"The algorithms used for the simulations are abstractly based on how organisms are evolved, but not on any particular real-life organism," explained Lehman.
The average evolvability of organisms in the final population is shown as a function of distance from the initial starting niche averaged over 50 independent simulations. The main result is that there is a significant correlation between increasing distance from the initial niche and increasing evolvability. The plotted line indicates the line of best fit by linear regression. Image Source: PLOS ONEThe team's hypothesis is unique and is in contrast to most popular theories for why evolvability increases.
"An important implication of this result is that traditional selective and adaptive explanations for phenomena such as increasing evolvability deserve more scrutiny and may turn out unnecessary in some cases," Stanley said.
Stanley is an associate professor at UCF. He has a bachelor's of science in engineering from the University of Pennsylvania and a doctorate in computer science from the University of Texas at Austin. He serves on the editorial boards of several journals. He has over 70 publications in competitive venues and has secured grants worth more than $1 million. His works in artificial intelligence and evolutionary computation have been cited more than 4,000 times.
SOURCE University of Central Florida
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