Gorillas, chimpanzees and human beings all belong to a group of mammals called primates. These species, including modern humans, descend from a common ancestor.
Hominisation began with the appearance of a bipedal primate species in east Africa. The members of this species walked on their back legs and are therefore considered the first hominids.
The most significant anatomical changes that occurred during hominisation were:
Genes are the part of a cell where an individual's physical characteristics are stored. This is the genetic information that children inherit from their parents. If a change occurs in this genetic information (a mutation), this can be passed on to the next generation. If this change becomes hereditary, this species changes or a new species is created.
When two species (the one that has mutated and the original one) share the same environment, the one that is least adapted will probably decrease in number until it disappears. This explains why we are the only surviving hominids. This theory is called evolution by natural selection and was developed by the British naturalist Charles Darwin.
During the time of Australopithecus, the climate changed and the wooded areas where they lived became savannahs with less vegetation. It became increasingly difficult to obtain food. The genus Homo adapted best to this new situation.
Activity 1
Look at the information about the evolution of hominids.
Activity 2
Which change in the process of hominisation do you think was the most important? Explain why.
Activity 3
Why do you think that walking upright was so important in the process of hominisation?
Activity 4
The development of language is attributed to changes in the larynx. What other change(s) could it be attributed to?
Activity 5
Think about how natural selection works. Why do you think that other species of hominids have not survived but some species of less-evolved primates, such as gorillas, have?
