In evolutionary developmental biology, the concept of genetic assimilation describes a process by which an environmentally induced phenotype becomes fixed as an inherited trait through natural selection. Biologist Conrad Waddington demonstrated this mechanism by subjecting fruit fly embryos to heat shock, which caused them to develop crossveinless wings. By selectively breeding the individuals that exhibited this response over several generations, Waddington produced a line of flies that consistently developed crossveinless wings even in the complete absence of temperature stress. This empirical demonstration showed that phenotypic plasticity can precede and channel subsequent evolutionary changes in the genome.
Desmos Graphing Calculator
Verbal·Craft and Structure·Text Structure and Purpose
mediumWhich choice best states the function of the underlined sentence in the text as a whole?
A
It details the specific experimental procedure and outcome that substantiated Waddington’s theoretical claim.
B
It challenges earlier evolutionary models that attributed morphological changes entirely to environmental stressors.
C
It illustrates why fruit flies are inadequate model organisms for studying genetic assimilation in vertebrate populations.
D
It highlights an unforeseen experimental failure that forced Waddington to reconsider his hypothesis.