I'm afraid that Gary Taubes is a known sensationalist who has been heavily criticised for exaggeration, fraud etc. Here is one critique of Gary Taubes, followed by his retort, followed by the previous reviewer's answer to that retort:-

http://reason.com/archives/2003/03/01/big-fat-fake

http://reason.com/archives/2003/03/01/an-exercise-in-vitriol-rather

http://reason.com/archives/2003/03/01/gary-taubes-tries-to-overwhelm

As for wild animals, they get cancer just like humans do:-

http://www.livescience.com/9680-cancer-kills-wild-animals.html

Now, I will grant that there are likely factors, other than diet, which influence the chance of getting cancer, such as environmental pollution, but it's just not correct to state that humans never got cancer in hunter-gatherer days. Sure, many hunter-gatherers did not survive to the point in old age where cancer-risk is highest, but that means nothing. I do agree that a healthier diet will reduce cancer risk to some extent, though.

Geoff