books.google.co.il - Our ability to walk on two legs is not only a characteristic human trait but one of the things that made us human in the first place. Once our ancestors could walk on two legs, they began to do many of the things that apes cannot do: cross wide open spaces, manipulate complex tools, communicate with...https://books.google.co.il/books/about/Lowly_Origin.html?hl=iw&id=O5UBzFXmch0C&utm_source=gb-gplus-shareLowly Origin
