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“”Physics is like sex: sure, it may give some practical results, but that's not why we do it.
Sex can refer to a number of things:
- The number 6 in Latin (and in Swedish!)
- Biological sex: What kind of sex organs, characteristics, hormones, etc a critter has. For Biologists, “male” and “female” are only distinguished by the motility of their gametes. That is, if the gamete moves itself, it's produced by a male, if the gamete does not move itself, it is produced by a female. This is because a biological definition of sex has to work for all sexually reproductive life, and not just humans/mammals.
- The action of identifying the biological sex of a (usually newborn) organism (sexing chickens but not having sex with chickens)
- Sexual intercourse: Interpersonal activities involving previously mentioned reproductive organs. Check out our separate article on this subject to learn more!
- Sexual reproduction: When two different critters of approximately the same species each contribute roughly half of their genetic information in the form of gametes, which are then combined to be the genetic information of their offspring, in an embryo or seed of some sort. Closely related species, such as horses and donkeys, are capable of interbreeding, although the offspring are generally sterile. Asexual reproduction is basically cloning. Sexual reproduction, although a simple biological concept, is swaddled in fear and loathing by many odd subsets of the human race.
“”We do not even in the least know the final cause of sexuality; why new beings should be produced by the union of the two sexual elements... The whole subject is as yet hidden in darkness.
|—Charles Darwin, 1862|
The evolution of sexual reproduction was a mystery to scientists ever since Darwin mentioned the mysteries and problems of it in 1862. However, since that time, advances in genetics have shone light on how, and perhaps why, the evolution of reproduction occurred. Firstly, although sexual reproduction is a lottery, a shuffled genetic deck maximizes the chances of offspring surviving long enough to reproduce themselves. If children in a litter were all genetically identical clones of their (single) parent, if a virus gets one, it gets them all. Viruses typically look for stretches of DNA with a specific sequence. If that sequence happens to cross a recombination boundary in a sexually-reproducing species, it will be harder for the virus to latch onto. Secondly, sexually reproducing organisms evolve faster, being able to create more variations based on sexual recombination of genes. This has been indicated with microorganisms, where those capable of sexual reproduction adapted more effectively and at a faster rate than asexual organisms. Thirdly, asexual reproduction is at a disadvantage, because any beneficial mutation can only be passed on through direct descendants. With sexual reproduction, the beneficial mutations have a greater ability to spread and the potential to combine with other, complementary mutations.
The very first sexual reproduction is considered to have occurred around 2 billion years ago, sparking an increase in biodiversity. It is thought that in the first form, sexual reproduction was "optional", a way of reproducing when the organism was experiencing harsh conditions. This is seen today in many species of yeast. Due to the advantages of sexual reproduction described above, sexual reproduction eventually took over asexual reproduction in many species, resulting in the mandatory — and extremely entertaining — activity that we know today.
|“|| -Can someone tell me who first suggested the idea of reproduction without sex?
-Um, your wife?
—David Lightman (Matthew Broderick), in WarGames
The opposite of sexual reproduction is asexual reproduction, which is reproduction without recourse to sexual intercourse.
For many monocellular and even small multicellular organisms, it effectively amounts to self-cloning. The creature grows, copies its DNA into two, and splits into two organisms. Each has the same DNA (discounting copy errors etc.) and is thus effectively the same organism.
Parthenogenesis is the production of offspring by the female of the species without fertilization of the ovum. Some insects and, rarely, reptiles or amphibians have been known to use this method of reproduction.
Sex vs gender
Usually, a creature's biological sex is congruent with its gender (e.g., none, male, female, intersex, or hermaphroditic).
However, unlike biological sex, gender refers to an individual's self-conception and self-presentation. A person born with male sex organs may feel more comfortable being a woman (or vice versa) and presenting herself as such to society. This presentation, however, is often forcibly suppressed in some countries (socially and/or legally). Many transgender people also take physical steps to align their physical body/sex with their gender such as Hormone Replacement Therapy (HRT), Top/Chest Surgeries, Genital Reconstructive Surgery (GRS), and many more. For example, a transgender woman would identify as female, socially present as female, and in most cases, take HRT in the forms of estradiol & testosterone blockers. It is worth noting that one's sex cannot be fully changed (in every aspect). Various and numerous sexually dimorphic phenotypic traits can be modified and contest the individual's previous overall phenotypic sex classification.
Etymology of the less polite form
The Internet being what it is, occasionally an email will circulate telling a fanciful tale about how the "f" word came into existence. Supposedly it was an acronym for Fornication Under Consent of King. This of course is false from beginning to end. Words deriving from acronyms is a very modern phenomenon, unknown before the 20th century, there is no record of such an "F.U.C.K." pass being issued by any government, and the word has a long history derived from our fellow Germanic languages. So the next time you see this email in your inbox, you may reply to the sender and suggest they fornicate off (with or without consent of king).
- "On the two forms, or dimorphic condition, in the species of Primula, and on their remarkable sexual relations", Journal of the Proceedings of the Linnean Society of London (Botany) 6: 77-96.
- Zimmer, Carl (5 June 2009). "On the Origin of Sexual Reproduction". Science 324 (5932): 1254-1256.