Transposons May Have Played a big role in evolution

Over the last few years, what scientists had once called “junk” DNA is not quite jusk to them anymore. Scientists have just recently had to deal with the fact that less than five percent of the human genome contains functioning genes. Of the other ninety-five percent, half is anonymous noncoding DNA. The other half is parasitic DNA known as transposons. Researchers now believe that transposons may not have been the excess baggage that people originally took them for, but one real player in evolution. These rogue bits of DNA may be what distinguish us from our closest primate kin.
In the 1940’s Barbara McClintock developed the idea that DNA sequences are not always static. They sometimes move around from place to place, leaving biological peculiarities in their wake. With this idea she was able to explain why the Indian corn she was studying did not inherit the coloring in the orderly fashion of Gregor Mendel’s peas. Instead, something was causing variations to appear- m...