Just read a really plausible novel called The Prophesy Gene. The main characters uncover a number of unintended genetic mutations as a result of the 1980s Aral Sea environmental disaster in Central Asia and the accidental release of a genetically modified strain of anthrax.  The author makes a pretty scary claim that mankind is stifling its own evolution by premeditated and accidental genetic engineering and mutations because we can’t possibly understand all of the consequences to ecosystems and dormant genetic sites and the food chain when we monkey with this stuff.  For example, some people eat oxen that have grazed on mutated vegetation and those people’s digestive systems irreparably stop working.  Or some dangerous fungus that humans eradicate because it causes disease but they don’t realize that it also sequesters carbon dioxide and could reverse global warming.  But I think the best one is that if it wasn’t for scientist’s genetic meddling, humans might one day evolve senses that bats and sharks have like hunting by their internal sonar or the ability that butterflies and some birds have to navigate by the earth’s magnetic field.  The book is by Stuart Schooler.  His website is http://www.stuartschooler.com and there’s a link to a blog and a Youtube video (https://vimeo.com/53365895).