Definitions

Haldane

Haldane

[hawl-deyn]
Haldane, John Burdon Sanderson, 1892-1964, British geneticist, biologist, and popularizer of science; son of John Scott Haldane. As one of the most influential scientists of the 20th cent, he studied relationships among different disciplines and problems, including the consequence of Mendelian genetics on evolutionary theory, the relationship between enzymology and genetics, and the application of mathematics and statistics to the study of biology. His works which are numerous, include (with John S. Huxley) Animal Biology (1927), The Causes of Evolution (1937), New Paths in Genetics (1941), and Biochemistry of Genetics (1954). Haldane also wrote fiction and verse as well as political works in support of his Marxist position, notably The Marxist Philosophy and the Sciences (1938). Disillusioned with Marxism in the 1940s and 50s, he eventually moved to India to conduct scientific research.

See biography by R. W. Clark (1984); study ed. by K. R. Dronamraju (1968).

Haldane, John Scott, 1860-1936, British scientist, b. Edinburgh; father of John Burdon Sanderson Haldane. He made many important contributions to mine safety, investigating principally the action of gases, the use of rescue equipment, and the incidence of pulmonary disease. He devised a decompression apparatus for the safe ascent of deep-sea divers, and in 1905 he discovered that regulation of breathing is determined by the effect of the amount of carbon dioxide in the blood on the respiratory center of the brain. He studied barometric pressure on an expedition to Pikes Peak, Colo., in 1911. He founded the Journal of Hygiene, and his published works include Organism and Environment (1917), New Physiology (1919), Respiration (1922), and The Philosophy of a Biologist (1936).

(born May 3, 1860, Edinburgh, Scot.—died March 14/15, 1936, Oxford, Oxfordshire, Eng.) British physiologist and philosopher. He developed procedures for studying the physiology of breathing and of the blood and devices for measuring hemoglobin and for analyzing blood gas and mixtures of gases. He discovered that breathing is regulated in large part by the effect of the amount of carbon dioxide in the blood on the brain's respiratory centre. He studied the effects of low air pressure, investigated the action of gases in mine suffocations and explosions (an important contribution to mine safety), and developed a staged decompression method for ascent from deep-sea dives. He also tried to clarify the philosophical basis of biology. He was the brother of Richard Burdon Haldane and the father of J.B.S. Haldane.

Learn more about Haldane, John Scott with a free trial on Britannica.com.

J.B.S. Haldane

(born Nov. 5, 1892, Oxford, Oxfordshire, Eng.—died Dec. 1, 1964, Bhubaneswar, India) British geneticist. Son of John Scott Haldane, he began studying science as his father's assistant at age eight and later received his M.A. from Oxford. Haldane, R. A. Fisher, and Sewall Wright, in separate mathematical arguments based on analyses of mutation rates, population size, patterns of reproduction, and other factors, related Charles Darwin's evolutionary theory and Gregor Mendel's concepts of heredity. Haldane also contributed to the theory of enzyme action and to studies in human physiology.

Learn more about Haldane, J(ohn) B(urdon) S(anderson) with a free trial on Britannica.com.

(born May 3, 1860, Edinburgh, Scot.—died March 14/15, 1936, Oxford, Oxfordshire, Eng.) British physiologist and philosopher. He developed procedures for studying the physiology of breathing and of the blood and devices for measuring hemoglobin and for analyzing blood gas and mixtures of gases. He discovered that breathing is regulated in large part by the effect of the amount of carbon dioxide in the blood on the brain's respiratory centre. He studied the effects of low air pressure, investigated the action of gases in mine suffocations and explosions (an important contribution to mine safety), and developed a staged decompression method for ascent from deep-sea dives. He also tried to clarify the philosophical basis of biology. He was the brother of Richard Burdon Haldane and the father of J.B.S. Haldane.

Learn more about Haldane, John Scott with a free trial on Britannica.com.

J.B.S. Haldane

(born Nov. 5, 1892, Oxford, Oxfordshire, Eng.—died Dec. 1, 1964, Bhubaneswar, India) British geneticist. Son of John Scott Haldane, he began studying science as his father's assistant at age eight and later received his M.A. from Oxford. Haldane, R. A. Fisher, and Sewall Wright, in separate mathematical arguments based on analyses of mutation rates, population size, patterns of reproduction, and other factors, related Charles Darwin's evolutionary theory and Gregor Mendel's concepts of heredity. Haldane also contributed to the theory of enzyme action and to studies in human physiology.

Learn more about Haldane, J(ohn) B(urdon) S(anderson) with a free trial on Britannica.com.

Haldane's rule relating to hybrids of species and extended to speciation in evolutionary theory is easily stated:

It was originally formulated in 1922 by the British evolutionary biologist J. B. S. Haldane. It is sometimes referred to as Haldane's law.

In many organisms, such as mammals or Drosophila flies, males are the heterogametic sex, in that they have XY sex chromosomes, whereas females are homogametic, with XX chromosomes. However, in some other animals (i.e. birds, butterflies) and plants, the reverse is usually true. Haldane's rule has been shown in a number of different hybrid crosses where either the male or the female is the heterogametic sex.

The fact that hybrid sterility and inviability can evolve due to Haldane's rule in such a vast array of different organisms is quite striking. However, the actual explanation of this phenomenon is rather complicated. Many different hypotheses have been advanced to explain the genetic basis of Haldane's rule.

  • The dominance hypothesis: Heterogametic hybrids are affected by all, recessive and dominant, X-linked genes involved in incompatibilities, while homogametic hybrids are only affected by the dominant ones.
  • Faster male hypothesis: Males genes evolve faster due to sexual selection.
  • Meiotic drive: In hybrid populations, selfish genetic elements inactivate sperm cells (i.e: A X-linked drive factor inactivates a Y-bearing sperm and vice versa).
  • Faster X theory: X-linked have a larger effect in reproductive isolation.

The dominance hypothesis is the most widely accepted explanation of Haldane's rule. However, the individual hypotheses are not mutually exclusive and many causes might potentially act together and cause hybrid sterility and inviability in the heterogametic sex. The faster male hypothesis, for example, receives support from a study in Asian Elephants.

Haldane's rule has a correspondence with the observation that some negative recessive genes are sex-linked and express themselves more often in men than women, such as color blindness or haemophilia.

References

References

  • Coyne, J.A. (1985): The genetic basis of Haldane's rule. Nature 314(6013): :736-738. Retrieved 2007-JAN-26. NCBI Pubmed Abstract.
  • Forsdyke, Donald (2005): Haldane's rule Version of 2005-DEC-6. Retrieved 2006-OCT-11.
  • Haldane, J. B. S. (1922): Sex ratio and unisexual sterility in hybrid animals. J. Genet. 12: 101-109.
  • Naisbit, Russell E., Jiggins, Chris D., Linares, Mauricio, Salazar, Camilo, Mallet, James. (2002)Hybrid Sterility, Haldane's Rule and Speciation in Heliconius cydno and H. melpomene. Genetics 2002 161: 1517-1526

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