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Gemmules

Gemmules are a term used in biology to refer to two distinct concepts.

In sponge biology, gemmules are internal, dormant buds produced by freshwater sponges such as Spongilla. They form within the sponge’s body (the mesohyl) and consist of clusters of archaeocytes surrounded by a protective coat that may include spicules and organic material. Gemmules enable asexual reproduction and survival under unfavorable environmental conditions. When conditions improve, gemmules can germinate to give rise to new sponge individuals, often contributing to rapid recolonization of a habitat after drought, freezing, or sediment disturbance. Gemmulation tends to be seasonal and is particularly important for sponges living in fluctuating freshwater environments.

Historically, the term gemmule appears in the 19th century in Charles Darwin’s theory of pangenesis. Darwin

Etymology: from Latin gemma, meaning “bud.” See also pangenesis; sponges; germ plasm.

proposed
that
tiny
particles,
gemmules,
travel
from
various
parts
of
the
body
to
the
reproductive
organs
to
influence
offspring,
providing
a
mechanism
for
inheritance
and
disguise
of
acquired
traits.
The
concept
was
part
of
an
early
attempt
to
reconcile
observations
about
heredity
with
a
particulate
mechanism.
It
was
later
abandoned
with
the
rise
of
Mendelian
genetics
and
modern
molecular
biology,
but
the
term
remains
a
notable
historical
reference
in
discussions
of
heredity
theories.