Theory of Knowledge - Course Companion for Students Marija Uzunova Dang Arvin Singh Uzunov Dang

II. Perspectives
origin story of genetics as a discipline
The
with Gregor Mendel’s experiments on
starts
plants in the mid-19th century. The humble
pea
triggered one of the greatest breakthroughs
pea
scientific history: the Mendelian laws of
in
and Mendel himself has been
inheritance,
Mendel’s 1865 article was not
However,
as important until many years after
recognized
death. It was rediscovered in 1902 and
his
ripples from Russia to the United States
sent
stoking controversy in how fundamental
by
such as variation, evolution, heredity,
concepts
and gene were defined, understood
mutation
work, and related to one another. In the
to
disputed Bateson’s claim that
Weldon
findings could be applied generally,
Mendel’s
Mendel’s experiments used purebred
because
plants especially designed to eliminate
pea
natural variability responsible for creating
the
In Weldon’s view, therefore, the
complexity.
were unrepresentative of real-world
plants
and it was more important to
conditions,
William Bateson (who coined
between
popularized the term “genetics”) and
and
former teacher, Walter Frank Raphael
his
Weldon and Bateson had very
Weldon.
reactions: Bateson was a champion of
different
inheritance, arguing that “factors”
Mendelian
he called them genes) determine “visible
(later
of organisms according to the
characteristics”
laws. Weldon remained sceptical
Mendelian
several accounts because when he tried to
on
Mendel’s experiments with peas, he
replicate
a much greater variety of characteristics,
found
much more of a continuum. His peas
along
not look as discretely different as Mendel
did
them looking—decidedly yellow or
describes
wrinkled or round.
green,
the environment. Weldon died four
with
into this controversy, without finding
years
answer for the complex interactions
an
genes and environment. In fact,
between
are only beginning to unravel
epigeneticists
now. Weldon was largely forgotten; while
this
smooth-sailed into textbook glory,
Mendel
Bateson at the helm, both celebrated for
with
7
Box 7.5: Mendel in the textbook
dubbed the “father of genetics”.
UK, it sparked a short but fiery public dispute
Figure 7.4
Takn
from Wldon’s artil
“Mndl’s Laws of
Altrnativ Inhritan
in Pas” (1902)
understand how natural variability interacts
discovering genetics.
186