Recent from talks
Bateman's principle
Knowledge base stats:
Talk channels stats:
Members stats:
Bateman's principle
Bateman's principle, in evolutionary biology, states that the variability in reproductive success (or reproductive variance) is greater in males than in females. It was first proposed by Angus John Bateman (1919–1996), an English geneticist and botanist. The principle is based on the observation that, while males can produce millions of sperm cells with little effort, females must invest higher levels of resources in order to nurture a relatively small number of egg cells. Bateman's paradigm thus views females as the limiting factor in reproduction over which males compete in order to copulate.
Although Bateman's principle has served as a cornerstone for the study of sexual selection for many decades, it has been controversial. One study refers to the paper in which Bateman presented his ideas and experimental results as "classic, but divisive" and also describes it as presenting "concepts that remain influential and debated in sexual selection." However, some scientists have criticized Bateman's experimental and statistical methods or have produced conflicting evidence. Others have defended the validity of the principle and have produced evidence in support of it.
Bateman contributed to the literature on sexual selection only once in his lifetime in a paper published in 1948. Bateman's paper was an attempt to refine Darwin's theory of sexual selection, which he saw not as flawed, but as incomplete. Darwin's theory of sexual selection explained "phenotypic differences between adult males and females of the same species [sexual dimorphism] and thus the evolution and maintenance of exaggerated secondary sexual characteristics that do not increase survival." Based on his observation of numerous animal species, Darwin attributed the exaggerated attributes of some species' males (such as physical ornaments — colors, large antlers — that do not enhance odds of survival) to differential sexual selection operating on males. He attributed this development of traits that might lower survival rates to males being generally more "eager" than females to engage in sexual activity, though "he was at a loss … to explain this sex difference."
Bateman's study was an attempt to add greater scientific rigor to Darwin's original insight and to explain the different roles played by males and females in many mating systems. He did this by studying reproduction in a small population of fruit flies, Drosophila melanogaster. He felt that if he were to provide a concrete demonstration of how sexual selection played out in the reproductive success of certain species, he could refine Darwin's ideas.
Although subsequent authors have attributed a wide range of ideas to Bateman, his basic principle can be expressed in three simple statements. The first is that male reproductive success increases with the number of mates they copulate with, while female reproductive success does not. The second is that male reproductive success will show greater variance than female reproductive success. The third is that sexual selection will have a greater effect on the sex with greater variance in reproductive success.
After publication, Bateman's paper fell into relative obscurity until interest in it was revived by Robert Trivers in a paper published in 1972. Triver's insight was that a key factor in determining in the intensity of sexual selection and sexual dimorphism across species was differences between males and females in the amount of parental investment required to produce and nurture offspring. Trivers adopted a broad definition of parental investment, which included gamete production, incubation or gestation and the parental care required to raise young offspring. Trivers theorized that sexual selection should be more intense in the sex that expends fewer resources on parental investment (which, in many species, are males).
Subsequent research in this area makes frequent reference to both Bateman and Trivers and established both as influential scientists in the field of evolutionary biology.
The starting point for the theory underpinning Bateman's principle is the idea that, in a 'typical' species, it is the females who have to make larger investments in order to produce each offspring. In an original, but quite narrow insight, Bateman attributed the origin of the unequal investment to the differences between males and females in cost differences of gamete production: sperm are cheaper to produce than eggs, which are larger and more nutrient-rich than sperm cells. Under a schematic representation of a typical mating system, a single male can fertilize all of a female's eggs, whereas a female will not produce more offspring by mating with more than one male. A male's fertility is therefore closely related to the number of times he is able to mate with receptive females over his lifetime. In contrast, a female's potential reproductive success is limited by how many eggs she can produce (Bateman also allowed that milk production in mammals also increased reproduction costs for females).
Hub AI
Bateman's principle AI simulator
(@Bateman's principle_simulator)
Bateman's principle
Bateman's principle, in evolutionary biology, states that the variability in reproductive success (or reproductive variance) is greater in males than in females. It was first proposed by Angus John Bateman (1919–1996), an English geneticist and botanist. The principle is based on the observation that, while males can produce millions of sperm cells with little effort, females must invest higher levels of resources in order to nurture a relatively small number of egg cells. Bateman's paradigm thus views females as the limiting factor in reproduction over which males compete in order to copulate.
Although Bateman's principle has served as a cornerstone for the study of sexual selection for many decades, it has been controversial. One study refers to the paper in which Bateman presented his ideas and experimental results as "classic, but divisive" and also describes it as presenting "concepts that remain influential and debated in sexual selection." However, some scientists have criticized Bateman's experimental and statistical methods or have produced conflicting evidence. Others have defended the validity of the principle and have produced evidence in support of it.
Bateman contributed to the literature on sexual selection only once in his lifetime in a paper published in 1948. Bateman's paper was an attempt to refine Darwin's theory of sexual selection, which he saw not as flawed, but as incomplete. Darwin's theory of sexual selection explained "phenotypic differences between adult males and females of the same species [sexual dimorphism] and thus the evolution and maintenance of exaggerated secondary sexual characteristics that do not increase survival." Based on his observation of numerous animal species, Darwin attributed the exaggerated attributes of some species' males (such as physical ornaments — colors, large antlers — that do not enhance odds of survival) to differential sexual selection operating on males. He attributed this development of traits that might lower survival rates to males being generally more "eager" than females to engage in sexual activity, though "he was at a loss … to explain this sex difference."
Bateman's study was an attempt to add greater scientific rigor to Darwin's original insight and to explain the different roles played by males and females in many mating systems. He did this by studying reproduction in a small population of fruit flies, Drosophila melanogaster. He felt that if he were to provide a concrete demonstration of how sexual selection played out in the reproductive success of certain species, he could refine Darwin's ideas.
Although subsequent authors have attributed a wide range of ideas to Bateman, his basic principle can be expressed in three simple statements. The first is that male reproductive success increases with the number of mates they copulate with, while female reproductive success does not. The second is that male reproductive success will show greater variance than female reproductive success. The third is that sexual selection will have a greater effect on the sex with greater variance in reproductive success.
After publication, Bateman's paper fell into relative obscurity until interest in it was revived by Robert Trivers in a paper published in 1972. Triver's insight was that a key factor in determining in the intensity of sexual selection and sexual dimorphism across species was differences between males and females in the amount of parental investment required to produce and nurture offspring. Trivers adopted a broad definition of parental investment, which included gamete production, incubation or gestation and the parental care required to raise young offspring. Trivers theorized that sexual selection should be more intense in the sex that expends fewer resources on parental investment (which, in many species, are males).
Subsequent research in this area makes frequent reference to both Bateman and Trivers and established both as influential scientists in the field of evolutionary biology.
The starting point for the theory underpinning Bateman's principle is the idea that, in a 'typical' species, it is the females who have to make larger investments in order to produce each offspring. In an original, but quite narrow insight, Bateman attributed the origin of the unequal investment to the differences between males and females in cost differences of gamete production: sperm are cheaper to produce than eggs, which are larger and more nutrient-rich than sperm cells. Under a schematic representation of a typical mating system, a single male can fertilize all of a female's eggs, whereas a female will not produce more offspring by mating with more than one male. A male's fertility is therefore closely related to the number of times he is able to mate with receptive females over his lifetime. In contrast, a female's potential reproductive success is limited by how many eggs she can produce (Bateman also allowed that milk production in mammals also increased reproduction costs for females).