Could we create a real-life superhero by changing human biology itself? The form and function of the human body, once entirely delimited by nature, are now fluid concepts thanks to recent advances in biomedical science and engineering. Professor, author, and comic book enthusiast E. Paul Zehr uses Marvel's Captain America -- an ordinary man turned into an extraordinary hero, thanks to a military science experiment -- as an entry-point to this brave new world of science, no longer limited to the realm of fiction. With our ever-expanding scientific and technological prowess, human biological adaptability is now in our fallible human hands. Thanks to the convergence of biology, engineering, and technology, we can now alter our abilities through surgery, pharmaceutical enhancement, technological fusion, and genetic engineering. Written in an accessible manner, Chasing Captain America explores these areas and more, asking what the real limits of being human are, how far we should bend those limits, and how we may be forced to reshape human biology if we are to colonize planets like Mars.