Marcelo Gleiser

We all know that the world is changing. Fast. But do we know where it is going? Not exactly.

That being the case, how can we control where it is going? And who is the "we" in control? In Hacking Darwin: Genetic Engineering and the Future of Humanity, the technology futurist, geopolitical expert, past White House fellow, and, like this author, dedicated endurance athlete Jamie Metzl paints a picture that is at once wondrous and terrifying.

Stephen Hawking is one of those rare luminaries whose life symbolizes the best humanity has to offer.

His uncanny creativity as a theoretical physicist and his decades-long struggle with a horribly debilitating motor neuron disease (also known as amyotrophic lateral sclerosis or Lou Gehrig's disease) inspired millions to revisit their bonds with science and with their personal challenges.

There is a paradox with living as a human nowadays.

A 2014 article from the United Nations states that about 54 percent of the human population lives in urban areas (more by now), a proportion that is projected to increase to 66 percent by 2050. By 2045, the report says, more than six billion people will crowd cities.