Bipedalism can be define as a form of terrestrial locomotion, in which the organism moves with the help of two rear limbs or legs. Typical bipedal movements includes the hoping, running and walking. The evolution of the human bipedalism occurred in primates in about 4 million years ago with Sahelanthropus (oldest human ancestors or African Apes). The human ancestor Sahelanthropus led to the morphological alterations in the human skeleton including changes in the bones such as size of the bones of the foot, knee size, shape and orientation of the vertebral column, and leg length. All these changes contributed to the bipedalism.
When a biologist counts the number of zebras in a population each year and notices an increase in the zebra population, this would be an example "of <span>observation"</span>
The formation of a phosphodiester bond between adjacent nucleotides is catalyzed by the DNA polymerases. They do this efficiently only if the incoming base on the incoming nucleoside triphosphate is complementary to the base on the template strand and can bind efficiently.