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单词 pangenesis
释义

pangenesis


pan·gen·e·sis

P0043000 (păn-jĕn′ĭ-sĭs)n. A theory of heredity proposed by Charles Darwin in which gemmules containing hereditary information from every part of the body coalesce in the gonads and are incorporated into the reproductive cells.
pan′ge·net′ic (-jə-nĕt′ĭk) adj.pan′ge·net′i·cal·ly adv.

pangenesis

(pænˈdʒɛnɪsɪs) n (Biology) a former theory of heredity, that each body cell produces hereditary particles that circulate in the blood before collecting in the reproductive cells. See also blastogenesis1 pangenetic adj ˌpangeˈnetically adv

pangenesis

the theory advanced by Darwin, now rejected, that each part of the body is represented in each cell by gemmules, which are the basic units of hereditary transmission. — pangenetic, adj.See also: Evolution
the theory advanced by Darwin, now rejected, that transmission of traits is caused by every cell’s throwing off particles called gemmules, which are the basic units of hereditary transmission. The gemmules were said to have collected in the reproductive cells, thus ensuring that each cell is represented in the germ cells. Cf. blastogenesis. — pangenetic, adj.See also: Heredity
Translations

Pangenesis


pangenesis

[pan′jen·ə·səs] (biology) Darwin's comprehensive theory of heredity and development, according to which all parts of the body give off gemmules which aggregate in the germ cells; during development, they are sorted out from one another and give rise to parts similar to those of their origin.

Pangenesis

 

a speculative theory of heredity and development.

According to Hippocrates, who lived in the fifth and fourth centuries B.C., close physical resemblances between children and their parents were caused by the fact that in animals and man “the seed separates from the rest of the body.” Similar views were developed in the 17th century by G. Borelli and in the 18th century by G. Buffon. In 1868, C. Darwin advanced the concept of pangenesis in his “provisional hypothesis of pangenesis.” Attempting to encompass in a single theory the phenomena of individual development and of variability, heredity, and phylo-genetic development, Darwin suggested that submicroscopic germs called gemmules migrate from all parts of the body through the circulatory system to the sex cells. The gemmules ensure that descendants will develop characteristics similar to those of their parents, including newly acquired characteristics. Darwin’s hypothesis received neither support nor empirical confirmation. Thus, F. Galton, attempting in 1871 to ascertain whether there are gemmules in the blood that determine the color of hair, transfused blood from dark-colored rabbits to light-colored ones and found that the transfusion caused no change in the coloring of the offspring. Darwin’s hypothesis of pangenesis is important in that it contains the concept, later confirmed, of the discreteness, or corpuscular nature, of the material basis of heredity.

Intracellular pangenesis, a hypothesis advanced by H. de Vries in 1889, suggested that hereditary instincts are caused by the presence of material particles (pangens) in living protoplasm. In contrast to Darwin, de Vries denied that pangens were transferred to the sex cells; he believed that each cell nucleus from its very inception contains all the pangens distinctive to a given individual. Elements of de Vries’ hypothesis have been proven valid in modern biology, especially since the successful transplantation of somatic cell nuclei to egg cells without nuclei has proved that complete genetic information is contained in the nuclei of the body’s cells.

REFERENCES

Darwin, C. Soch., vol. 4. Moscow-Leningrad, 1951.
Vries, H. de. Intracellulare Pangenesis. Jena, 1889.

L. IA. BLIAKHER

pangenesis


pangenesis

(păn-jĕn′ĭ-sĭs)n. A theory of heredity proposed by Charles Darwin in which gemmules containing hereditary information from every part of the body coalesce in the gonads and are incorporated into the reproductive cells.
pan′ge·net′ic (-jə-nĕt′ĭk) adj.pan′ge·net′i·cal·ly adv.

pangenesis

(păn″jĕn′ĕ-sĭs) [Gr. pan, all, + genesis, generation, birth] The discredited hypothesis that each cell of the parent is represented by a particle in the reproductive cell, and thus each part of the organism reproduces itself in the progeny.
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更新时间:2024/11/11 17:52:05