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Although neutral evolution remains the consensus theory among modern biologists, [3] and thus Kimura's resolution of Haldane's dilemma is widely regarded as correct, some biologists argue that adaptive evolution explains a large fraction of substitutions in protein coding sequence, [4] and they propose alternative solutions to Haldane's dilemma.
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's article on abiogenesis in 1929 introduced the "primordial soup theory", which became the foundation for the concept of the chemical origin of life. He established human gene maps for haemophilia and colour blindness on the X chromosome, and codified Haldane's rule on sterility in the heterogametic sex of hybrids in species.
Haldane's remark alluded to the fact that if an individual loses its life to save two siblings, four nephews, or eight cousins, it is a "fair deal" in evolutionary terms, as siblings are on average 50% identical by descent, nephews 25%, and cousins 12.5% (in a diploid population that is randomly mating and previously outbred). But Haldane also ...
The work of Fisher, Haldane and Wright founded the discipline of population genetics. This integrated natural selection with Mendelian genetics, which was the critical first step in developing a unified theory of how evolution worked. [4] [5] John Maynard Smith was Haldane's pupil, whilst W. D. Hamilton was
It was produced by hybridisation experiments in the 1920s, when crosses were made between yak bulls and both pure bison cows and bison–cattle hybrid cows. [1] As with many other inter-specific crosses, only female hybrids were found to be fertile (Haldane's rule). Few of the hybrids survived, and the experiments were discontinued in 1928. [2]
The HuffPost/YouGov poll consisted of 3,000 completed interviews conducted May 8 to 29 among U.S. adults, including 124 women who are childless and reported not wanting children in the future. It was conducted using a sample selected from YouGov's opt-in online panel to match the demographics and other characteristics of the adult U.S. population.
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 ...