http://medicalxpress.com/ en-us Medical Xpress internet news portal provides the latest news on Health and Medicine. When Charles Darwin first sketched how species evolved by natural selection, he drew what looked like a tree. The diagram started at a central point with a common ancestor, then the lines spread apart as organisms evolved and separated into distinct species. http://medicalxpress.com/news/2013-01-history-lesson-genes-dna-populations.html Genetics Wed, 09 Jan 2013 13:47:45 EST news276961656