HISTORY
Since
the beginning of human history, people have wondered
how traits are inherited from one generation to the
next. Although children often look more like one parent
than the other, most offspring seem to be a blend
of both parents. It wasn't until 1865 that an Austrian
monk named Gregor Mendel found that individual traits
are determined by genes which are inherited from the
parents. He conducted his experiments on pea plants.
He focused on seven identifiable traits of the pea
plants. He found that each trait had two alternate
forms of a gene. For example, seed colour can be green
or yellow. However, he found that gene characteristics
do not blend. For example, a cross between a pure
bred green seeded and a pure bred yellow seeded pea
do not produce a pea with intermediate green yellow
characteristics. In fact the resulting offspring is
either a green or yellow pea - with yellow pea offspring
occuring 3 times more frequently than green pea offspring.
The
reason for this behaviour - George Mendel later attributed
to the fact that some genes are dominant and some
are recessive. In the case of the peas the yellow
gene is dominant while the green gene is recessive.
Mendel
published his important work on heredity in 1866.
But only in 1900 was his work recognized more or less
independently by three investigators.
