This is still one of my favorite arguments against evolution!
“Renowned geneticist and inventor of the gene gun, Dr John Sanford,10 in his landmark book Genetic Entropy and the Mystery of the Genome, highlights the problem.11 The relentless net effect of random mutations (which evolutionists suppose to be the ‘engine’ of evolution) is actually degradation or complete destruction of function.
As Dr Sanford puts it, “So every one of us is a mutant, many times over!”
Such is the alarmingly high rate of increase in the human population’s total number of accumulated mutations (i.e. the genetic load or genetic burden) from generation to generation, that evolutionary geneticists are bewildered as to why we haven’t already become extinct. For example, evolutionary geneticist Alexey Kondrashov asked, “Why aren’t we dead 100 times over?” However, their puzzlement arises because they believe that humans have been on earth for at least 100,000 years (some would say a million years).”
Read more here: http://creation.com/time-no-friend-of-evolution
Or get this book for more details: http://www.discovercreation.org/shop/youth-adult-books/genetic-entropy-the-mystery-of-the-genome/