LIKE those old clothes at the back of your wardrobe, genetic junk can accumulate at the beginnings of genes because cells don’t get around to throwing it away.
Researchers in Denmark used genomic databases to examine how junk DNA sequences known as introns are distributed in 18 different organisms. After genes are copied into RNA, the intron sequences must be snipped out before the copy is sent to the cell’s protein-producing machinery.
They found that the fewer introns a cell has, the more the introns are concentrated at the beginning of genes. They conclude that intron-poor organisms are actively removing…
