Question

Describe the changes in brain function that accompany changes in brain complexity that occurred with evolution.

Answer 1

For the sake of tracing the history of human brain complexity, there exist no actual brain to track the time scale. However, this is possible by evaluating the rare fossils and skulls to carry out the studies. This is enough to provide the evidence about the volumes of ancient brains and the approximation of cerebral areas.

The species of Australopithecus afarensis, commonly known as Lucy, has the cranial capacity of 400-500. Their brain shown slight changes as compared to the apes. Their neocortex began to expand which helped them to reorganize visual processing function to other parts of the brain.

Homo habilis which appeared 1.9 MYA , showed the expansion in the Broca's area which is responsible for language comprehension. Homo erectus had the cranial capacity of 600. Homo sapiens had the cranial capacity of 1200 or more.

The above mentioned cases were the major changed remarked during evolution of human brain, but, below is the precise details of cranial capacity of individual human ancestors:

• Orangutans: 275–500 cm³
• Chimpanzees: 275–500 cm³
• Gorillas: 340–752 cm³
• Homo sapiens sapiens: 1,496 cm³
• Homo neanderthalensis: 1,427 cm³
• Homo heidelbergensis: 1,262 cm³
• Homo erectus soloensis: 1,155 cm³
• Homo erectus: 1,093 cm³
• Homo habilis: 610 cm³
• Australopithecus africanus: 491cm³
• Australopithecus afarensis: 445 cm³

PS: For the values of cranial capacaity, help from internet was taken.