SCIENCE CORNER XV
Sexual Selection, Debunked
by Molly Lambert
Everybody pile on now! Let's go eighths on a baby!
I know I keep hammering this point home, but it's just so insane to me that scientists believed until very recently that sexual selection was dependent on male animals being slutty and females being monogamous. Animals are sluts! They will do whatever the hell it takes to ensure reproduction occurs. We are talking about Nature!
To use a couple of true clichés, variety is the spice of life and one animal's trash is another animal's treasure. We all like wildly different things, often at the same time. I have some sort of weird predisposition towards Blond Men, but that doesn't mean I'm not also constantly attracted to Dark-Haired and/or skinned dudes as well. Sexual attraction is not exactly a mutually exclusive thing.
I am not so attracted to fellow Gingers though, that'd be sick.
There is no such thing as a dysgenic trait. Genetic variety rulez!
Amplexus is like frottage (dry humping) that gets you pregnant. If you're a frog. It's literally Latin for "embrace" and it can involve more than two frogs, kind of a froggy swingers' party where everyone tries to knock a girl frog up. When multiple partners are involved (toads, newts, snakes, and other animals do a similar thing for sex) it's known as a "mating ball."
Froggy Went A Courtin' And He Did Ride
Basically female frogs fuck all the male frogs in the area and let their sperm fight it out. Competing sperm will literally form a circular barrier around the egg to stop a rival male's sperm from fertilizing it first. Similar behavior has been observed in other species, especially birds and monkeys.
Like many snakes, the male garter snake has two penises, called "hemipenes," on each side of its body. The male will try to use the best-positioned penis to mate with the female in the center of the mating ball.
Polyandry is a type of mating system where females mate with more than one male during a breeding season, resulting in the offspring of one female having more than one father. Polyandry has been traditionally thought of as a rare phenomenon, however recent research has shown this trend is widespread throughout the animal kingdom, with evidence of multiple mating by females in many groups. This trend is surprising because it appears to go against the basic principles of sexual selection.
Funfact! The form of polyandry in which two (or more) brothers marry the same woman is known as fraternal polyandry, and it is believed by many anthropologists to be the most frequently encountered form. Double funfact, the most well known human practitioners of polyandry are in Tibet.
Scientist Kate Hutchence lays it out for you:
The current consensus is that females are mating multiply to gain genetic benefits for thier offspring. There are several different ways this might be happening, and it is possible that a combination of these factors may be driving polyandry:
1. Genetic bet-hedging: females mate with many males to gain greater genetic diversity in their offspring, thereby hedging their bets against a changing environment.
2. Genetic improvement or Trade-up: females are remating with a good quality male in order to 'trade-up' on a previous mating with a low-quality male.
3. The good genes model: females mate multiply to gain access to 'good genes' for their offspring by trading up, or post-copulatory cues (this assumes that there in one best male for all females).
4. The genetic incompatibility model: females are mating multiply to gain access to the male that they are most genetically compatible with by trading-up, or postcopulatory cues (this assumes that there is no one best male for all females, and that due to the genetic complexity of organisms each female has her own best mate).
The belief that Polygyny is somehow the "natural" order of the world is how the FLDS Mormons convince themselves and their followers old dudes should get to have 400 little girl wives. The fact that (founder of Mormonism) Joseph Smith was a total wingnut is something they tend to leave out.
Comfort Wives: Big Love Style
Charles Darwin believed and taught that women were biologically inferior to men, and this idea greatly influenced his theories of natural selection and the hundred plus years of scientific research that followed. It was also taken for granted that white people were superior, and that "nature" was to thank for all this. This is also how white dudes got to have ethnic "comfort wives" and not consider it cheating.
Comfort Wives: Creole Plaçage Style
That we are just now untangling the ingrained sexism and racism in Science is one of the many reasons I am thrilled to be living in the 21st century and not any other, when I would probably have been burned at the stake.
My science hero Stephen Jay Gould
The tremendous Natural Historian polymath Stephen Jay Gould is to thank for debunking much of the pseudoscience that passed for evolutionary psychology in the past. He would be stoked about this election, that's for sure.
Charles Darwin listed the advantages of marrying, which included: "constant companion, (friend in old age) who will feel interested in one, object to be beloved and played with—better than a dog anyhow—Home, and someone to take care of house". Darwin reasoned that as a married man he would be a "poor slave, worse than a Negro," but then reminisces that, "one cannot live the solitary life, with groggy old age, friendless and childless staring in one's face" Darwin concludes his discussion on the philosophical note, "there is many a happy slave" and shortly thereafter, married his cousin.
Darwin concluded that adult females of most species resembled the young of both sexes and from this and the other evidence, "reasoned that males are more evolutionarily advanced than females". Many anthropologists contemporary to Darwin concluded that "women's brains were analogous to those of animals," which had "overdeveloped" sense organs "to the detriment of the brain".
Carl Vogt, a University of Geneva natural history professor who accepted many of "the conclusions of England's great modern naturalist, Charles Darwin," argued that "the child, the female, and the senile white" all had the intellect and nature of the "grown up Negro"
"Even in the most intelligent races are a large number of women whose brains are closer in size to those of gorillas than to the most developed male brains. This inferiority is so obvious that no one can contest it for a moment; only its degree is worth discussion. Women represent the most inferior forms of human evolution and are closer to children and savages than to an adult, civilized man.
They excel in fickleness, inconsistency, absence of thought and logic, and incapacity to reason. Without a doubt there exist some distinguished women, very superior to the average man but they are as exceptional as the birth of any monstrosity, as, for example, of a gorilla with two heads; consequently, we may neglect them entirely."
Superior Women = A Gorilla With 2 Heads = Double Bananas!
It is most generally applied to a pollinator attempting to copulate with a flower. Some flowers mimic a potential female mate visually, but the key stimuli are often chemical and tactile. This form of mimicry in plants has been titled Pouyannian mimicry.
Orchids commonly achieve reproduction in this manner, secreting chemicals from glands called osmophores located in the sepals, petals, or labellum, that are indistinguishable from the insect's natural pheromones. The pollinator then has a pollinia attached to its body, which it transfers to the stigma of another flower when if it attempts another 'copulation'. Pollinators are often bees and wasps of the order Hymenoptera, and flies.
Ontogeny does not really recapitulate phylogeny, but it's still a great turn of phrase.
Ernst Haeckel and friend
Parthenogenesis: In hybridogenesis reproduction is not completely asexual, but instead hemiclonal: half the genome passes intact to the next generation, while the other half is discarded. Hybridogenetic females can mate with males of a "donor" species and both will contribute genetic material to the offspring.
When the female offspring produce their own eggs, however, the eggs will contain no genetic material from their father, only the chromosomes from the offspring's own mother; the set of genes from the father is invariably discarded. This form of reproduction is seen in some live-bearing fish of the genus Poeciliopsis as well as in the waterfrog Rana esculenta and the donor waterfrog species Rana lessonae.
MARMORKREBS, the Amazonian crayfish civilization.
Female shark parthenogenesis
Apomixis is the process whereby plants produce asexually, and it very rarely involves a male. Meaning the mother produces a copy of herself using only her own DNA.
A unique example of male apomixis has recently been discovered in the Saharan Cypress, Cupressus dupreziana, where the seeds are derived entirely from the pollen with no genetic contribution from the female "parent."
Gregory Goodwin Pincus experimented with parthenogenesis in rabbits and later invented birth control. Thanks for The Pill, Mr. Pincus! It's helped all us liberated womynfolk to become more polyandrous than ever.
In short, chocolate chocolate chocolate! ACK!
Molly Lambert is the senior Science Expert at This Recording.
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