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Apparently the first use of the term "Haldane's dilemma" was by paleontologist Leigh Van Valen in his 1963 paper "Haldane's Dilemma, Evolutionary Rates, and Heterosis". Van Valen writes: [8] Haldane (1957 [= The Cost of Natural Selection]) drew attention to the fact that in the process of the evolutionary substitution of one allele for another ...
In humans, barring intersex conditions causing aneuploidy and other unusual states, it is the male that is heterogametic, with XY sex chromosomes.. Haldane's rule is an observation about the early stage of speciation, formulated in 1922 by the British evolutionary biologist J. B. S. Haldane, that states that if — in a species hybrid — only one sex is inviable or sterile, that sex is more ...
Haldane was the first to have thought of the genetic basis for human cloning, and the eventual artificial breeding of superior individuals. For this he introduced the terms "clone" and "cloning", [ 113 ] modifying the earlier "clon" that had been used in agriculture since the early 20th century (from Greek klōn , twig).
Haldane's dilemma regarding the cost of selection was used as motivation by Kimura. Haldane estimated that it takes about 300 generations for a beneficial mutation to become fixed in a mammalian lineage, meaning that the number of substitutions (1.5 per year) in the evolution between humans and chimpanzees was too high to be explained by ...
Objections to evolution have been raised since evolutionary ideas came to prominence in the 19th century. When Charles Darwin published his 1859 book On the Origin of Species, his theory of evolution (the idea that species arose through descent with modification from a single common ancestor in a process driven by natural selection) initially met opposition from scientists with different ...
The Haldane-Muller theorem of mutation–selection balance says that the load depends only on the deleterious mutation rate and not on the selection coefficient. [6] Specifically, relative to an ideal genotype of fitness 1, the mean population fitness is exp ( − U ) {\displaystyle \exp(-U)} where U is the total deleterious mutation rate ...
Pages in category "Works by J. B. S. Haldane" The following 6 pages are in this category, out of 6 total. ... Haldane's dilemma; Haldane's rule; O. On Being the Right ...
The time at which insemination occurs during the estrus cycle has been found to affect the sex ratio of the offspring of humans, cattle, hamsters, and other mammals. [25] Hormonal and pH conditions within the female reproductive tract vary with time, and this affects the sex ratio of the sperm that reach the egg.