Mate choice copying
This article needs additional citations for verification. (January 2011) (Learn how and when to remove this template message)
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: 
- An initial preference is established by observing an individual's choice when being exposed to potential mates for the first time
- This first individual is then allowed to observe another individual making a choice (but is prevented from interfering with the other individual)
- 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 had 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 or "dismissed").
Mate choice copying has been found in a wide variety of different species, including (but not limited to): invertebrates, like the common fruit fly (Drosophila melanogaster)  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) and humans. 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 choice 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 melanogaster. Mate-copying has also been found to depend on environmental conditions. For instance, no mate-copying was found in Drosophila melanogaster in poor weather conditions.
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 who 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.
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:
- Copiers might copy the choice of individuals who have not carefully assessed individuals (i.e. copy a wrong choice)
- Copiers might not copy the correct choice (i.e. copy a choice that was not actually made).
Any 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 which the copier spent incorrectly copying, 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 as much attention from scientists.
- "Social learning and mate choice in quail", psych.upenn.edu.
- Dagaeff, A.-C.; Pocheville, A.; Nöbel, S.; Loyau, A.; Isabel, G.; Danchin, E. (2016). "Drosophila mate copying correlates with atmospheric pressure in a speed learning situation". Animal Behaviour. 121: 163–174. doi:10.1016/j.anbehav.2016.08.022.
- F. Mery, 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.
- Bowers, Robert I.; Place, S.S.; Todd, P.M.; Penke, L.; Asendorpf, J.B. (2012). "Generalization in mate-choice copying in humans". Behavioral Ecology. 23 (1): 112–124. doi:10.1093/beheco/arr164.
- Auld, H.L.; Punzalan, D.; Godin, J.-G.J.; Rundle, H.D. (2009). "Do female fruit flies (Drosophila serrata) copy the mate choice of others?". Behavioural Processes. 82 (1): 78–80. CiteSeerX 10.1.1.673.4392. doi:10.1016/j.beproc.2009.03.004. PMID 19615615.
- "The role of model female quality in the mate choice copying behaviour of sailfin mollies". NCBI.nlm.nih.gov.
- "Mate Choice Copying in Humans". Springerlink.com.
- "Beauty is in the eye of your friends". Newscientist.com.
- "Generalization in mate-choice copying in humans". Behavioral Ecology