delinquent noun [C]. âº a âperson, usually âyoung, who âbehaves in a way that is âillegal or not âacceptable to most âpeople: âjuvenile delinquents.
Sahelanthropus may have walked on two legs. The oldest evidence for walking on two legs comes from one of the earliest humans known, Sahelanthropus. Walking upright may have helped this species survive in the diverse habitats near where it livedâincluding forests and grasslands.
Human walking is about 75% less costly than both quadrupedal and bipedal walking in chimpanzees. Some hypotheses have been supported that bipedalism increased the energetic efficiency of travel and that this was an important factor in the origin of bipedal locomotion. Humans save more energy than quadrupeds when walking but not when running. Human running is 75% less efficient than human walking.