There a few hominid traits that can inform us about modern human biology. One of them being from the Sahelanthropus tchadensis small teeth, large brow ridges and flat face, characteristics very similar to ours. The placement of the foramen magnum is located unmet the skull making it bipedal. Another hominid that carries a important trait is the Orrorin tugenensis, which has bipedal legs. Legs built to carry ad balance weight one leg at a time. It also has has long ape like arms which infers that humans were still spending times in the trees while standing bipedal. The Ardipithecus I thought was the most visibly similar to humans. The later species had slightly smaller canines verses older species having larger ape like canines. Lastly, the Australopithcus afarensis having reduced canines and molars as well as loss of adduceable big toe (making it look similar to our feet) and a pelvis, suggesting full time bipedalism. All of these enlighten us on modern human biology because all these changes happened over time as a result of adapting to new situations and environments. Most giving us a little information at a time to what is was like to be a human then internally and externally. These have all impacted human evolution over all. Humans evolved on had to either adapt/ evolve or die. We chose to evolve and for lack of better words get with the times. Fossilized skeletal remain of early human ancestors can help anthropologist reconstruct and learn from the past by examining what traits/ abilities went with those remains. For example if in the past humans had two thumbs instead of one anthropologist can father dissever what that second thumb was necessary for.