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WHAT ARE CELLS MADE OF?

Is Our Brain Bigger Than That of the Dinosaurs?

 

What Differentiates Humans from Animals

Biologists classify humans as animals and part of the animal kingdom. Like our nearest relatives, the apes, humans are also mammals. Humans have evolved from apes, but there are features that differentiate us from other animals- including apes. These include the upright walk, our opposable thumb, our special ability to communicate by a language, and our highly developed brain. Our brain allowed our ancestors, like the Neanderthals, to invent tools.

 




Did humans evolve from apes?

Today, one can think of humans and apes as cousins. They have common ancestors, but have not descended directly from each other. About 5-7 million years ago, a line of man-like apes grew apart, and evolved independently of the other apes. The oldest, almost completely intact skeleton of an upright ancestor of human- the Australopithecus- was found in 1974 in Ethiopia (Africa). The scientists named it ‘Lucy’.

 Do animals use tools?

Animals do make use of tools for getting food or for protecting themselves. Apes reach for sticks or stones when threatened, sea otters break their favorite food, the shells, with the help of stones, and a species of finches pick out insects from tree trunks, with a long cactus quill. For generations the young ones of animals have watched the traits of the adults and imitated them exactly. Humans, on the other hand, may change the traits according to personal requirements. Humans advanced and discover new things by adapting and learning. It is hard to believe that the hand axe made by prehistoric men out of stone has today given rise to sharp knives, chainsaws, and many other things.

 

Is our brain bigger than that of the dinosaurs?

Dinosaurs had small brains, much smaller than the human brain. The dinosaur brain often weighed only a thousandth of their huge body mass. An adult human brain is about one-fifth of its body mass, on an average around 14000g. Since the early hominid creatures, whose skeletons were found in Africa, the brain mass of humans has increased threefold. In comparison, the size of the brains of other animals has hardly changed in the course of millions of years.

 



Who were the Neanderthals?

The Neanderthals were the people who lived 130,000 - 30,000 years ago, but then died out due to unknown reasons. One theory is that, the other lines of humans were stronger and eliminated them. The Neanderthals were about 1.70 m tall, had a heavy built body and were very powerful. They needed this power and strength to hunt the wild woolly mammoths and rhinoceros with their home made spears and knives. They made cloths out of animal skin, lived in caves, and used fire. Their name is derived from the place from where their remains were found, the Neander Valley.

 


What is so special about thumbs?

Unlike other animals our thumb is opposable, which means that it has free movement and can be placed opposite the fingers of the same hand. This helps us to grip things securely and lets us do delicate jobs like threading a needle. Our grooved fingerprints prevent smooth things from slipping away. This movement of the hand, combined with the freely moving shoulder joint and the upright posture, gave our ancestors a development advantage: tools or weapons could be used for a specific purpose with great power.



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