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Pangenesis
(gcide) | Pangenesis \Pan*gen"e*sis\, n. [Pan- + genesis.] (Biol.)
An hypothesis advanced by Darwin in explanation of heredity.
[1913 Webster]
Note: The theory rests on the assumption, that the whole
organization, in the sense of every separate atom or
unit, reproduces itself, the cells throwing off minute
granules called gemmules, which circulate freely
throughout the system and multiply by subdivision.
These gemmules collect in the reproductive organs and
products, or in buds, so that the egg or bud contains
gemmules from all parts of the parent or parents, which
in development give rise to cells in the offspring
similar to those from which they were given off in the
parent. The hypothesis also assumes that these gemmules
need not in all cases develop into cells, but may lie
dormant, and be transmitted from generation to
generation without producing a noticeable effect until
a case of atavism occurs. This is an ingenious
hypothesis, but now known to be wrong. Although now, a
hundred years later, we know that all transmitted
genetic information (other than that in plasmids) is
contained in the genome of a single cell, scientists
are still only beginning to understand the development
process.
[1913 Webster +PJC] |
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