Editing Behavioral ecology (section)

===Mate choice by genes===
When males' only contribution to offspring is their sperm, females are particularly choosy.  With this high level of female choice, sexual ornaments are seen in males, where the ornaments reflect the male's social status. Two hypotheses have been proposed to conceptualize the genetic benefits from female [[mate choice]].<ref name="Davies">{{cite book |author=Nicholas B. Davies |author2=John R. Krebs |author3=Stuart A. West |title=An Introduction to Behavioral Ecology|year=2012|publisher=Wiley-Blackwell|location=West Sussex, UK|isbn=978-1-4051-1416-5|pages=193–202}}</ref>

First, the good genes hypothesis suggests that female choice is for higher genetic quality and that this preference is favored because it increases fitness of the offspring.<ref name=ryan>{{cite journal|last=Ryan|first=Michael J.|author2=Anne Keddy-Hector|title=Directional patterns of female mate choice and the role of sensory biases |journal=The American Naturalist|date=March 1992|volume=139|pages=S4–S35|jstor=2462426|doi=10.1086/285303|s2cid=86383459}}</ref>  This includes [[Handicap principle|Zahavi's handicap hypothesis]] and [[Evolutionary arms race|Hamilton and Zuk's host and parasite arms race]]. Zahavi's handicap hypothesis was proposed within the context of looking at elaborate male sexual displays. He suggested that females favor ornamented traits because they are handicaps and are indicators of the male's genetic quality. Since these ornamented traits are hazards, the male's survival must be indicative of his high genetic quality in other areas. In this way, the degree that a male expresses his sexual display indicates to the female his genetic quality.<ref name="Davies" />  Zuk and Hamilton proposed a hypothesis after observing disease as a powerful selective pressure on a rabbit population. They suggested that sexual displays were indicators of resistance of disease on a genetic level.<ref name="Davies" />

Such 'choosiness' from the female individuals can be seen in wasp species too, especially among ''[[Polistes dominula]]'' wasps. The females tend to prefer males with smaller, more elliptically shaped spots than those with larger and more irregularly shaped spots. Those males would have reproductive superiority over males with irregular spots.

In [[Marbled newt|marbled newts]], females show preference to mates with larger crests. This however, is not considered a handicap as it does not negatively affect males' chances of survival. It is simply a trait females show preference for when choosing their mate as it is an indication of health and fitness.<ref>{{Cite journal |last1=Zuiderwijk |first1=Annie |last2=Sparreboom |first2=Max |date=1986-01-01 |title=Territorial Behaviour in Crested Newt Triturus Cristatus and Marbled Newt T. Marmoratus (Amphibia, Urodela) |url=https://brill.com/view/journals/btd/56/2/article-p205_2.xml |journal=Bijdragen tot de Dierkunde |language=en |volume=56 |issue=2 |pages=205–213 |doi=10.1163/26660644-05602002 |issn=0067-8546|doi-access=free }}</ref>

Fisher's hypothesis of runaway sexual selection suggests that female preference is genetically correlated with male traits and that the preference co-evolves with the evolution of that trait, thus the preference is under indirect selection.<ref name=ryan/> Fisher suggests that female preference began because the trait indicated the male's quality. The female preference spread, so that the females' offspring now benefited from the higher quality from specific trait but also greater attractiveness to mates. Eventually, the trait only represents attractiveness to mates, and no longer represents increased survival.<ref name="Davies" />

An example of mate choice by genes is seen in the cichlid fish ''[[Tropheus moorii]]'' where males provide no parental care. An experiment found that a female ''T. moorii'' is more likely to choose a mate with the same color morph as her own.<ref>{{cite journal | last1 = Salzburger | first1 = Walter | last2 = Niederstätter | first2 = Harald | last3 = Brandstätter | first3 = Anita | last4 = Berger | first4 = Burkhard | last5 = Parson | first5 = Walther | last6 = Snoeks | first6 = Jos | last7 = Sturmbauer | first7 = Christian | year = 2006 | title = Colour-assortative mating among populations of ''Tropheus moorii'', a cichlid fish from Lake Tanganyika, East Africa | journal = Proceedings of the Royal Society B: Biological Sciences | volume = 273 | issue = 1584| pages = 257–66 | doi=10.1098/rspb.2005.3321 | pmid=16543167 | pmc=1560039}}</ref> In another experiment, females have been shown to share preferences for the same males when given two to choose from, meaning some males get to reproduce more often than others.<ref name=":3">{{cite journal | last1 = Steinwender | first1 = Bernd | last2 = Koblmüller | first2 = Stephan | last3 = Sefc | first3 = Kristina M. | year = 2011| title = Concordant female mate preferences in the cichlid fish ''Tropheus moorii'' | journal = Hydrobiologia | volume =  682| issue = 1| pages =  121–130| doi=10.1007/s10750-011-0766-5| pmid = 24293682 | pmc = 3841713 }}</ref>