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Sexual selection: Difference between revisions
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[[File:Sexual_sele.jpg|thumb|right|400px|[ | [[File:Sexual_sele.jpg|thumb|right|400px|[https://www.dartmouth.edu/~robertcox/Teaching_files/lecture9.ppt Source]]] | ||
Selection refers to a mechanism that decides who gets to pass on their genes to the next generation. '''Sexual selection''' refers to selection done by members of the opposite sex e.g. in accordance to their ''mate preferences'', but | Selection refers to a mechanism that decides who gets to pass on their genes to the next generation. '''Sexual selection''' refers to selection done by members of the opposite sex, e.g. in accordance to their ''mate preferences'', but the choices of parents and other family members influencing mating (e.g. arranged marriages) are also subsumed under sexual selection. | ||
=== Sexual selection can increase but also decrease fitness === | === Sexual selection can increase but also decrease fitness === | ||
Biologist John Endler conducted an experiment with Guppies (''Poecilia'') in a tank without predators. The female fish selected males who had strong contrast to the background as they stood out during mate selection. This then made the fish more visible to predators later reintroduced into the same tank.<ref>https://link.springer.com/chapter/10.1007/978-94-015-7682-6_7</ref><ref>[https://www.dartmouth.edu/~robertcox/Teaching_files/lecture9.ppt http://www.dartmouth.edu/~robertcox/Teaching_files/lecture9.ppt]</ref> | |||
Biologist John Endler conducted an experiment with Guppies (''Poecilia'') in a tank without predators. The female fish selected males who had strong contrast to the background as they stood out during mate selection. This then made the fish more visible to predators later reintroduced into the same tank.<ref>https://link.springer.com/chapter/10.1007/978-94-015-7682-6_7</ref><ref>http://www.dartmouth.edu/~robertcox/Teaching_files/lecture9.ppt</ref> | |||
This clearly demonstrates that sexual selection does not necessarily further and can even ''reduce'' survival. Related to this, one study showed men who have lots of sex were not healthier than others by various metrics.<ref>http://rsos.royalsocietypublishing.org/content/4/1/160603</ref> | This clearly demonstrates that sexual selection does not necessarily further and can even ''reduce'' survival. Related to this, one study showed men who have lots of sex were not healthier than others by various metrics.<ref>http://rsos.royalsocietypublishing.org/content/4/1/160603</ref> | ||
* Human beings are less effected by sudden environmental changes | * Human beings are less effected by sudden environmental changes | ||
Technology and human [[IQ|intelligence]] has evolved to the point sudden environmental changes, such as natural disasters, global warming, weekly weather changes, etc. Don't effect us as much as every other animal, due to our ability to forecast and plan for the future. | Technology and human [[IQ|intelligence]] has evolved to the point sudden environmental changes, such as natural disasters, global warming, weekly weather changes, etc. Don't effect us as much as every other animal, due to our ability to forecast and plan for the future. | ||
=== Other kinds of selection === | === Other kinds of selection === | ||
The main kind of selection is ''environmental'' selection referring to selection done by the environment or ecology e.g. due to famines, disease or natural death, and everything else that is not sexual. The Darwin award is primarily concerned with this selection. | The main kind of selection is ''environmental'' selection referring to selection done by the environment or ecology e.g. due to famines, disease or natural death, and everything else that is not sexual. The Darwin award is primarily concerned with this selection. | ||
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Lastly, there is ''group selection'', i.e. selection based on how the individual affects the survival and reproduction of entire groups. If a mutation results in better group survival, then that mutation may stick around because it may also (slightly) increase the individual's reproductive success. The effects of group selection are believed to be small compared to kin, sexual and environmental selection. | Lastly, there is ''group selection'', i.e. selection based on how the individual affects the survival and reproduction of entire groups. If a mutation results in better group survival, then that mutation may stick around because it may also (slightly) increase the individual's reproductive success. The effects of group selection are believed to be small compared to kin, sexual and environmental selection. | ||
=See also= | =See also= | ||
* [[Evolution]] | * [[Evolution]] | ||
*[[Fisherian runaway]] | *[[Fisherian runaway]] | ||
*[[Beauty]] | *[[Beauty]] | ||
== References == | == References == | ||
<references/> | <references /> | ||
[[Category:Theories]] | [[Category:Theories]] | ||
[[category:Science]] | [[category:Science]] | ||
{{B}} | {{B}} | ||