Becoming Human: How Evolution Made Us is available free in multiple formats:
You can go to the iBookstore to download the IBooks version (the most interactive and media-rich version).
You can also find multiple formats (such as ePub or PDF) at the ebook distributor, Smashwords (link here for the book in multiple formats).
Greg Downey 
Hello ,
Great to see a book on human evolution.
Its part of syllabus for anthropology optional in India’s most reputed exam to select bureaucrats and I teach them anthropology.
It would be great if i could a pdf copy of it .
I couldn’t access through smashwords. Any other possible way please let me know .
Thank you for such great work !