Scrabble?! COEVOLUTIONARY

Definitions of COEVOLUTIONARY in various dictionaries:

In evolutionary biology, an evolutionary arms race is a struggle between competing sets of co-evolving genes, traits, or species, that develop adaptations and counter-adaptations against each other, resembling an arms race. These are often described as examples of positive feedback. The co-evolving gene sets may be in different species, as in an evolutionary arms race between a predator species and its prey (Vermeij, 1987), or a parasite and its host. Alternatively, the arms race may be between members of the same species, as in the manipulation/sales resistance model of communication (Dawkins & Krebs, 1979) or as in runaway evolution or Red Queen effects. One example of an evolutionary arms race is in sexual conflict between the sexes, often described with the term Fisherian runaway. Thierry Lodé emphasized the role of such antagonistic interactions in evolution leading to character displacements and antagonist coevolution. The escalation hypothesis put forward by Geerat Vermeij speaks of more general conflicts and was originally based on his work with marine gastropod fossils. Co-evolution itself is not necessarily an arms race. For example, mutualism may drive co-operative adaptations in a pair of species. This is the case with certain flowers' ultra-violet color patterns, whose function is to guide bees to the center of the flower and promote pollination. Co-evolution is also interspecific by definition; it excludes intraspecific arms races such as sexual conflict. Evolutionary arms races can even be displayed between humans and micro-organisms, where medical researchers make antibiotics, and micro-organisms evolve into new strains that are more resistant. Evolutionary arms races often evolve when a trait is only beneficial compared to the population. For instance, if a tree has a mutation making it taller, it will have an advantage due to more sunlight. But as soon as other trees reach the same height, it loses that advantage. As soon as a taller tree appears, it has the advantage. In this example, the nearest peak of the evolutionary landscape moves as the population approaches it. Another example of runaway evolution in sexual selection is an elk's antlers. Having big antlers makes a male elk more likely to win a mate. In fact, having big antlers is a requirement to mate. As a result, elk evolve antlers that are incredibly costly to build, maintain, and fight with. By the end of the mating season, the average male loses 25% of his body weight due to fighting, which he has to make up before winter starts.