Mate choice copying

Mate choice copying (or just "mate copying") describes a non-independent mate choice event. Mate choice copying is said to occur when the likelihood that one individual (the "observer" or "focal individual") will mate with a particular individual (the "target") increases or decreases based upon observing a sexual interaction between the "target" and another individual. This is typically broken down into three steps ([1]):

1. An initial preference is established by observing an individual's choice when being exposed to potential mates for the first time

2. This first individual is then allowed to observe another individual making a choice (but is prevented from interfering with the other individual)

3. The first individual is then allowed to make a second choice.

Mate choice copying is said to occur when the first individual changes its choice after observing the choice of the second individual. Because the individual is basing its choice on what it observed occurring, mate choice copying will lead to an increase in the likelihood of mating if the observed interaction was successful (because the individual is observing another individual being preferred) and will lead to a decrease in the likelihood of mating if that interaction was unsuccessful (because the individual is observing another individual being not preferred/"dismissed").

Mate choice copying has been found in a wide variety of different species, including (but not limited to): invertebrates, like the fruit fly (Drosophila melanogaster) ^[1] fish, such as guppies (Poecilia reticulata), birds, like the Japanese quail (Coturnix japonica) and zebra finches (Taeniopygia guttata), and mammals, such as the Norway rat (Rattus norvegicus) and humans. Most studies have focused on females, but male mate copying has been found in sailfin mollies (Poecilia latipinna). Additionally, it does not have to occur in both sexes of a species. For example, male, but not female, mate copying was observed in the Atlantic Molly (Poecilia mexicana). Despite the strong evidence supporting this phenomenon, mate copying is not a universal occurrence. No evidence for mate copying was found in the fruit fly Drosophila serrata, for instance, although it is found in Drosophila melanogater.

Advantages of Mate Choice Copying

As with all biological processes, mate choice copying is expected to occur because it provides a fitness benefit to those performing it, relative to those that do not. As such, some research has focused on the benefits of this behavior and several possible benefits have been put forth by researchers. Some research on benefits found:

Mate copying allows for higher fitness by enabling a preference for a high quality mate to develop. The model demonstrates that copying may evolve when young females are poor at discrimination and need to learn what high-quality males look like. Mate choice copying may be a "prudent strategy" that provides benefits in that it allows offspring of a certain female to remain competitive because the offspring have the same alleles as many other individuals, because the mother has chosen to mate with the same male that many other females have mated with.</nowiki>

Disadvantages of Mate Choice Copying

Just as there are likely to be benefits to mate choice copying, there are likely to be costs as well. Choice and copying are likely not perfect and it is very possible for copiers to make errors. There are at least two main potential costs:

1. Copiers may copy the choice of individuals who have not carefully assessed individuals (i.e. copy a wrong choice) 2. Copiers may not copy the correct choice (i.e. copy a choice that was not actually made).

Either of these could potentially lead to copying the choice of an inferior mate. Indeed, a theoretical model suggests that mistakes may influence the evolution of mate copying. This model found that increasing the time the copier spent incorrectly copied another individual's choice decreased the benefits of copying. However, to date, there is no firm empirical data on the costs involved in copying. This is likely because, first, costs are hard to determine quantitatively and, second, because the entire field of mate choice copying is relatively new and, thus, has not yet received a lot of attention from scientists.

External links

• The role of model female quality in the mate choice copying behaviour of sailfin mollies
• Mate Choice Copying in Humans
• Beauty is in the eye of your friends

References

1. ^ Mery, F., S. A. M. Varela, E. Danchin, S. Blanchet, D. Parejo, I. Coolen, and R. H. Wagner. 2009. Public versus personal information for mate copying in an invertebrate. Current Biology 19:730-734