Reproduction And Development Codexery

Sexual reproduction

Haploid gametes fuse to form a diploid zygote.

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Sexual reproduction involves a complex life cycle where haploid gametes combine to form a diploid zygote, which is typical in animals but varies among other eukaryotes.[1] Sexual reproduction does not occur in prokaryotes like bacteria and archaea, though some bacterial processes are considered analogous.[2][3] Among multicellular eukaryotes like animals, fungi, and plants, sexual reproduction is the predominant life cycle, and it also happens in certain unicellular eukaryotes.[2]

Quick Facts

Known for
Most common life cycle in multicellular eukaryotes
Field
Biology

Facts from the source article.

Key facts and history

This genetic recombination increases diversity among future generations by exchanging similar but not identical regions of DNA.[4] Biologists propose several explanations for its development, including reducing deleterious mutations and increasing adaptation to changing environments.[5] Fossils from the Stenian period, dated to roughly 1.05 billion years ago, provide the earliest known evidence of sexual reproduction in eukaryotes.[6] Through meiosis, diploid parent cells in eukaryotes create haploid cells; this process includes DNA replication and the swapping of genetic material between homologous chromosomes.[4]

A clear benefit of sexual reproduction is that it boosts genetic variation and slows the buildup of detrimental mutations.[7] Sexual selection is a form of natural selection in which certain individuals achieve greater reproductive success by being more effective at finding mates.[8]

What the cited sources add

A 2014 article by Vogt notes that nearly all observable living organisms are based on sexual reproduction, despite it being far less efficient than non-sexual reproduction.[9] The same source states that Darwin's theory of sexual selection was revolutionary but was not demonstrated until after World War II by geneticist Angus John Bateman.[9] Vogt's article lists examples of traits promoted by sexual selection, such as the antlers of elk and deer.[9] The U.S. Forest Service account on ferns explains that at sexual maturity, male structures release sperm that swim through a film of water to fertilize the egg.[10]

That account also notes that in most ferns, sperm from one gametophyte most often fertilizes the egg of a different gametophyte.[10]

References

  1. Wikipedia, "Sexual reproduction" (CC BY-SA 4.0), which cites: John Maynard Smith & Eörz Szathmáry, The Major Transitions in Evolution, W. H. Freeman and Company, 1995, p 149; Chalker, "Epigenetics of Ciliates", Cold Spring Harbor Perspectives in Biology, 2013; Can Song, "Polyploid Organisms", Science China Life Sciences, 2012, p. 301–311 (original not read by us) en.wikipedia.org
  2. Wikipedia, "Sexual reproduction" (CC BY-SA 4.0), which cites: Nieuwenhuis, "The frequency of sex in fungi", Philosophical Transactions B, October 19, 2016; Woods, "Flowering Plants", Encyclopedia of Life, June 19, 2012; Chalker, "Epigenetics of Ciliates", Cold Spring Harbor Perspectives in Biology, 2013; Knop, "Yeast cell morphology and sexual reproduction – A short overview and some considerations", Comptes Rendus Biologies, 2011, p. 599–606 (original not read by us) en.wikipedia.org
  3. Wikipedia, "Sexual reproduction" (CC BY-SA 4.0), which cites: Narra, "Of What Use Is Sex to Bacteria?", Current Biology, September 5, 2015, p. R705–R710; Goodenough, "Origins of Eukaryotic Sexual Reproduction", Cold Spring Harbor Perspectives in Biology, March 1, 2014 (original not read by us) en.wikipedia.org
  4. Wikipedia, "Sexual reproduction" (CC BY-SA 4.0), which cites: "DNA Is Constantly Changing through the Process of Recombination", Nature, 2014 (original not read by us) en.wikipedia.org
  5. Wikipedia, "Sexual reproduction" (CC BY-SA 4.0), which cites: Gray, "Gene-flow between niches facilitates local adaptation in sexual populations", Ecology Letters, 2012, p. 955–962; Michod, "Adaptive value of sex in microbial pathogens", Infection, Genetics and Evolution, May 2008, p. 267–285; Bernstein, "Evolutionary Origin of Recombination during Meiosis", BioScience, 2010, p. 498–505; Bernstein, H.; Bernstein, C.; Michod, R. E. (2012) "DNA Repair as the Primary Adaptive Function of Sex in Bacteria and Eukaryotes ". Chapter 1, pp. 1–50, in DNA; Gorelick, "Sex reduces genetic variation: a mul en.wikipedia.org
  6. Wikipedia, "Sexual reproduction" (CC BY-SA 4.0), which cites: N.J. Butterfield, "Bangiomorpha pubescens n. gen., n. sp.: implications for the evolution of sex, multicellularity, and the Mesoproterozoic/Neoproterozoic radiation of eukaryotes", Paleobiology, 2000, p. 386–404; T.M. Gibson, "Precise age of Bangiomorpha pubescens dates the origin of eukaryotic photosynthesis", Geology, 2018, p. 135–138 (original not read by us) en.wikipedia.org
  7. Wikipedia, "Sexual reproduction" (CC BY-SA 4.0), which cites: Hussin, "Recombination affects accumulation of damaging and disease-associated mutations in human populations", Nature Genetics, 4 March 2015, p. 400–404; "DNA Is Constantly Changing through the Process of Recombination", Nature, 2014 (original not read by us) en.wikipedia.org
  8. Wikipedia, "Sexual reproduction" (CC BY-SA 4.0), which cites: Cecie Starr, "Biology: The Unity and Diversity of Life", Cengage Learning, 2013, p. 281; Vogt, "Large testicles are linked to infidelity", Phys.org, January 29, 2014; Agrawal, "Sexual selection and the maintenance of sexual reproduction", Nature, 2001, p. 692–695 (we also read that source) en.wikipedia.org
  9. Vogt, "Large testicles are linked to infidelity", Phys.org, January 29, 2014. facts only, no text reused. phys.org
  10. "Fern Reproduction", U.S. Forest Service. facts only, no text reused. fs.usda.gov

Each numbered sentence above was checked against the source it cites before publication. Sentences citing Wikipedia adapt text from the English Wikipedia article Sexual reproduction (contributors), used under CC BY-SA 4.0; this entry is available under the same licence. Other sources were used for facts only; no text or images are copied from them.

Also in the Codexery

Sexual reproduction · Reproductive BiologySexual reproduction · Reproduction & Development

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Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.

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