Barbara McClintock discovered the first transposons,
responsible for random colorations of kernels of maize,
naming them Activator and Dissociator.
This disproved the theory that genes were fixed
in their positions on their chromosomes,
and introduced the uncomfortable fact
that Mendelian inheritance and random mutations
did not entirely explain genetic variation.
Regulation
An archaeon, bacterium, or eukaryote
does not need all its genes all the time
but can express a gene to make a protein as needed.
Cells of multicellular organisms differentiate
to have different structures and functions
even though they contain complete genomes.
Not so simple
“Not so simple, buddy,”
said the Voice of Reality to the Poet.
“Remember all this evolved by chance.
Your simple notions, your simple lines
don’t begin to describe reality,
let alone if you had to make them rhyme!”
Barbara McClintock’s papers were highly technical and
conceptually difficult. It took thirty years for other scientists
to recognize and understand her work. Today, the idea of the
regulation of gene expression is a part of introductory genetics.
Barbara McClintock’s papers were highly technical and conceptually difficult. It took thirty years for other scientists to recognize and understand her work. Today, the idea of the regulation of gene expression is a part of introductory genetics.
See also in The book of science:
Readings on wikipedia: