The evolution of imperfection

"This book uncovers the ways natural selection leads to imperfection in humans and the implications of this for our understanding of how evolution works and human biology and health. The simplest version of evolution frames it as a gradual process that leads to constant improvement. This view holds that natural selection drives toward "perfection." Mutations in an organism's genome either harm or help its ability to reproduce; harmful ones don't last while beneficial ones are passed on and spread throughout a population. As Laurence Hurst argues in this book, the reality is far more complicated. This is particularly true for humans at the level of our DNA. Why, for example do we need so many sperm to fertilize one egg? Or why do we have a high rate of genetic disease? And why does much of our DNA appear to be pointless? These imperfections do not make sense when we assume that evolution is a constantly improving process, yet the more scientists study our genome the more they see things that look like imperfections. How, then, are they explained? After carefully introducing readers to what he means by perfection and imperfection and providing basic information about DNA, Hurst provides evidence for why the human genome retains imperfections. He argues that our small populations, high mutation rates, and mode of reproduction leave us vulnerable to all sorts of problems. In dissecting the evolution of our imperfection, Hurst illuminates what scientists are learning about the human genome and why it seems to cause so many issues despite our success as a species. Finally, despite what we might call our "rotten lot," evolutionarily speaking, we have our big brains and medicine to combat genetic disease and, at the end of the book, Hurst reviews what scientists are learning about curing genetically based diseases"--