We are closest to chimpanzees among the four apes.  

Picture courtesy: http://ohmygodfacts.com/7-interesting-chimpanzee-facts/2/

A human hemoglobin molecule differs from its chimpanzee counterpart in only a single amino acid.
A human hemoglobin molecule differs from its chimpanzee counterpart in only a single amino acid.

The study of positioning cannot be complete without understanding how we interpret and use language.

The study of how we acquired language cannot be complete without understanding how we evolved.

Anthropologists across the world have made the task of a learner like me easier. They have done all the hardwork and I am only proposing some theories. In bullet points, with more references and gratitude than I can possibly express- heres a critical view to our evolution.

  1. Considerable controversy exists about the identity of the first hominoid.
  2. Studies of ape DNA have explained a great deal about how the living apes evolved. The Asian apes evolved first. The line of apes leading to gibbons diverged from other apes about 15 million years ago, while orangutans split off about 10 million years ago (see figure 23.3). Neither are closely related to humans.
  3. The African apes evolved more recently, between 6 and 10 million years ago. These apes are the closest living relatives to humans; some taxonomists have even ad-vocated placing humans and the African apes in the same zoological family, the Hominidae
  4. We are closest to the chimpanzees, than any other kind of ape. This is well-established. Based on genetic differences, scientists estimate that gorillas diverged from the line lead-ing to chimpanzees and humans some 8 million years ago.
  5. What is particularly bizarre, is that because this split was so recent, the genes of humans and chimpanzees have not had time to evolve many genetic differences. For example, a human hemoglobin molecule differs from its chimpanzee counterpart in only a single amino acid. In general, humans and chimpanzees exhibit a level of genetic similarity normally found between closely related sibling species of the same genus.
  6. The common ancestor of apes and hominids is thought to have been an arboreal climber. Much of the subsequent evolution of the hominoids reflected different approaches to locomotion. Hominids became bipedal, walking up-right, while the apes evolved knuckle-walking, supporting their weight on the back sides of their fingers

When you are bipedal, a major part of the weight of your body is supported by your feet.

This alters many things, the gait, the relative position of the head to the rest of the body, the extensive freedom that the forelimbs (hands get) to accomplish other things rather than just support locomotion.

Seen over a few hundred years, each attribute contributes to a unique aspect of our evolution.