The water flea species Daphnia pulex is barely more than a millimeter long, is completely translucent, has no clear divisions between their various body parts...and has the largest genome of any animal we've ever encountered. It has an incredible 31,000 genes in its genome, over 8,000 more than humans have. So what's such a tiny organism doing with such a huge amount of genes?
The most basic reason is that Daphnia pulex is involved in runaway gene duplication, as it constantly churns out copies of genes at a far greater rate than other organisms. Project leader John Colbourne explains:
OT:yay 7000th post....