In this survey, most scientists failed to guess what fraction of the human genome is comprised of transposable elements
Despite the casual familiarity most scientists display towards the Human Genome Project, only one in five scientists knows that approximately one-half of the human genome is made up of transposable elements.
When members of The Science Advisory Board were asked to guess what fraction of the human genome is comprised of transposable elements, a surprising 82% of the 1,000+ respondents guessed incorrectly.
Of this majority, greater than one-third of those polled thought that the fraction was closer to one-quarter, while 26% of the participants believed that the fraction of contamination was so small that it should be considered negligible.
In fact, the human genome is literally littered with pieces of greater than three million transposable elements, primarily retroelements.
Retroelements are genetic elements that are capable of reverse transcription and integration into their host's genome.
"While the existence of integrated retroelements has been known for many years, I imagine that many scientists will be surprised by their abundance in the human genome," predicts Tamara Zemlo, director of scientific and medical communications for the Science Advisory Board.
Since integrated or endogenous retroelements can be passed from generation to generation, they have attracted a great deal of attention as to their influence in evolution. Moreover, there is increasing evidence that retroelements contributed to the evolution of the structure and function of the human genome.
Many evolutionary biologists speculate that an eruption of transposable element activity may well have been a factor in promoting the genetic changes that led to the emergence of the human species.
They propose that retroelements actually to this day play important roles in a number of physiological and pathological processes.
