![]() ![]() More generally, co-evolutionary cycles can arise when predator offense is costly and prey defense is effective against low offense predators. For instance, if a mutation that confers viral resistance in a species of bacteria becomes dominant, that may change the predator-prey relationship by rendering the bacteria population safe from harm. In microbial species with brief lifespans, evolutionary changes can happen within days or weeks.Įvolutionary changes can dramatically affect relationships between species, potentially making them more vulnerable or less vulnerable. In organisms such as birds or small mammals, those changes can be manifested in as few as ten generations. But organisms are evolving continuously, with certain phenotypes becoming dominant as environmental and other conditions favor them. ![]() ![]() We are not replacing the original theory, but proposing a more general model that opens the door to these new phenomena.”Įvolution is often perceived as an historical event, noted Weitz, who also has a courtesy appointment in the Georgia Tech School of Physics. “When you include evolution, the classic prey-predator dynamics have a much greater range of possible outcomes. “Our work shows that co-evolution can yield new and unique behavior at the population scale,” explained Joshua Weitz, an associate professor in the School of Biology at Georgia Tech. The research was supported by the National Science Foundation and the Burroughs Wellcome Fund. The new theory and analysis of these co-evolution cycles could help epidemiologists predict cycles of disease and the virulence of infectious agents, and lead to a better understanding of how population cycles may affect ecosystems. And then, using data collected by other scientists on three predator-prey pairs – mink-muskrat, gyrfalcon-rock ptarmigan and phage- Vibrio cholerae – they show how their theory could explain unexpected population cycles. Researchers at the Georgia Institute of Technology have proposed a theory to explain these co-evolutionary changes. In fact, it may appear as if the prey are eating the predators. When both species are evolving, the traditional cycle may reverse, allowing predator populations to peak before those of the prey. This canonical view of predator-prey relationships was first identified by mathematical biologists Alfred Lotka and Vito Volterra in the 1920s and 1930s.īut all bets are off if both the predator and prey species are evolving in even small ways, according to a new study published this week in the journal Proceedings of the National Academy of Sciences. When the predator population becomes too large, however, the prey population often plummets, leaving too little food for the predators, whose population also then crashes. When the number of prey increases, perhaps as their food supply becomes more abundant, predator populations also grow. Populations of predators and their prey usually follow predictable cycles. ![]()
0 Comments
Leave a Reply. |