Editing Reproduction (section)

==Asexual vs. sexual reproduction==

[[File:Evolsex-dia1a.svg|thumb|250px|right|Illustration of the ''twofold cost of sexual reproduction''. If each organism were to contribute to the same number of offspring (two), ''(a)'' the population remains the same size each generation, where the ''(b)'' asexual population doubles in size each generation.]]

Organisms that reproduce through asexual reproduction tend to grow in number exponentially. However, because they rely on mutation for variations in their DNA, all members of the species have similar vulnerabilities. Organisms that reproduce sexually yield a smaller number of offspring, but the large amount of variation in their genes makes them less susceptible to disease.

Many organisms can reproduce sexually as well as asexually. [[Aphid]]s, [[slime mold]]s, [[sea anemone]]s, some species of [[starfish]] (by [[fragmentation (reproduction)|fragmentation]]), and many plants are examples. When environmental factors are favorable, asexual reproduction is employed to exploit suitable conditions for survival such as an abundant food supply, adequate shelter, favorable climate, disease, optimum pH or a proper mix of other lifestyle requirements. Populations of these organisms increase exponentially via asexual reproductive strategies to take full advantage of the rich supply resources.<ref name=aphids>{{cite journal |last1=Yan |first1=Shuo |last2=Wang |first2=Wan-xing |last3=Shen |first3=Jie |title=Reproductive polyphenism and its advantages in aphids: Switching between sexual and asexual reproduction |journal=Journal of Integrative Agriculture |date=June 2020 |volume=19 |issue=6 |pages=1447–1457 |doi=10.1016/S2095-3119(19)62767-X|s2cid=218971234 |doi-access=free |bibcode=2020JIAgr..19.1447Y }}</ref>

When food sources have been depleted, the climate becomes hostile, or individual survival is jeopardized by some other adverse change in living conditions, these organisms switch to sexual forms of reproduction. Sexual reproduction ensures a mixing of the gene pool of the species. The variations found in offspring of sexual reproduction allow some individuals to be better suited for survival and provide a mechanism for selective adaptation to occur. The meiosis stage of the sexual cycle also allows especially effective repair of DNA damages (see [[Meiosis]]).<ref name=aphids />  In addition, sexual reproduction usually results in the formation of a life stage that is able to endure the conditions that threaten the offspring of an asexual parent. Thus, seeds, spores, eggs, pupae, cysts or other "over-wintering" stages of sexual reproduction ensure the survival during unfavorable times and the organism can "wait out" adverse situations until a swing back to suitability occurs.