Giant insects ruled the prehistoric skies during periods when Earth’s atmosphere was rich in oxygen. Then came the birds. After the evolution of birds about 150 million years ago, insects got smaller despite rising oxygen levels, according to a new study.
via ScienceDaily: Latest Science News http://www.sciencedaily.com/releases/2012/06/120604155703.htm?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+sciencedaily+%28ScienceDaily%3A+Latest+Science+News%29