how did the human brain go on changing
Answers
The size of our ancestors' brains was within the range of those of other apes living today. The Australopithecus afarensis, had skulls with internal volumes of between 400 and 550 milliliters, chimpanzee skulls have around 400 ml and gorillas between 500 and 700 ml. During this time, Australopithecine brains started to show subtle changes in structure and shape as compared with apes.
The final third of the evolution saw nearly all the action in brain size. Homo habilis, the first genus Homo saw a modest hop in brain size, including an expansion of a language-connected part of the frontal lobe. The first fossil skulls of Homo erectus, 1.8 million years ago, had brains averaging a bit larger than 600 ml.
From here the species embarked on a slow upward march, reaching more than 1,000 ml by 500,000 years ago. Early Homo sapiens had brains within the range of people today, averaging 1,200 ml or more. As our cultural and linguistic complexity, dietary needs and technological prowess took a significant leap forward at this stage, our brains grew to accommodate the changes. The shape changes accentuate the regions related to depth of planning, communication, problem solving and other more advanced cognitive functions.
The past 10,000 years of human existence actually shrank brains. Limited nutrition in agricultural populations may have been an important driver of this trend. Industrial societies in the past 100 years, however, have seen brain size rebound, as childhood nutrition increased and disease declined. Although the past does not predict future evolution, a greater integration with technology and genetic engineering may catapult the human brain into the unknown.
The process of evolution changed the human brain gradually.
It was not at all an overnight change but took thousands of years to improve the human brains.
With the environmental factors, food habits, the lifestyle and the thought processes working as a catalyst, the size of the human brains varied.
Almost all early Homo sapiens had their brain equal to the size of the brain of this generation, but it has passed through many changes during the period.