From early apes to modern humans

The human family

Humans belong to the primates, the group that also has the monkeys and the apes. NCERT follows the line from the early apes to modern humans in these steps. Books of A-Level and IB use the word hominin for the human line, and many Indian books use hominid. They mean the same line here.

From apes to the first hominids

• About 15 million years ago. Two primates, Dryopithecus and Ramapithecus, were alive. They were hairy, and they walked like gorillas and chimpanzees. Ramapithecus was more man-like, and Dryopithecus was more ape-like.
• 3 to 4 million years ago. Fossils of man-like bones have been found in Ethiopia and Tanzania. They show features of the hominids, and suggest that man-like primates walked in Eastern Africa. They were probably not taller than 4 feet, but they walked upright.
• About 2 million years ago. The Australopithecines probably lived in the grasslands of East Africa. They hunted with stone weapons, but they ate mainly fruit.

Homo habilis, Homo erectus and the Neanderthals

• Homo habilis: some of the bones among the finds were different. This creature was the first human-like being, the first hominid. Its brain capacity was 650 to 800 cc, where cc stands for cubic centimetres. It probably did not eat meat.
• Homo erectus: about 1.5 million years ago. Its brain was about 900 cc. It probably ate meat.
• Neanderthal man: brain size of about 1400 cc. It lived in the Near East and Central Asia between 100000 and 40000 years ago. It used hides to protect the body, and it buried the dead.
• Homo sapiens: it arose in Africa, moved across the continents and developed into distinct races. Modern Homo sapiens arose during the ice age, between 75000 and 10000 years ago.
• Cave art developed about 18000 years ago. Agriculture began about 10000 years ago, and the first human settlements began.

The brain capacity is the volume of the space in the skull, measured in cc. NCERT gives no capacity for modern Homo sapiens. The usual value in other books is about 1350 cc, and a range of about 1200 to 1500 cc. Other books give about 600 cc for Homo habilis and about 900 to 1000 cc for Homo erectus. Use the NCERT numbers in an examination.

What the numbers say

The brain capacity rises from about 725 cc in Homo habilis, the middle of the NCERT range, to 900 cc and then to 1400 cc. But the Neanderthals, with 1400 cc, had a slightly larger brain than the modern human. So a larger brain alone is not a measure of "more advanced". The shape of the brain, the tools and the language also matter.

Other trends in the line are walking upright on two legs (bipedalism), smaller jaws and teeth, a flatter face and the use of tools. A-Level and IB ask for these.

You should see that the bar grows from the first step to the third, and that the last bar, the modern human, is a little shorter than the Neanderthal bar.

Try it in Python

The program finds the percentage rise of the brain capacity from one step to the next, using the middle of each NCERT range.

Practise with new numbers

Common mistakes

• Saying that humans came from chimpanzees. Humans and chimpanzees share a common ancestor. Neither came from the other.
• **Putting Homo erectus after the Neanderthals.** The order is Homo habilis, Homo erectus, Neanderthal man, modern Homo sapiens.
• Mixing up the two early apes. Ramapithecus was more man-like. Dryopithecus was more ape-like.
• Using the wrong brain size. NCERT: habilis 650 to 800 cc, erectus about 900 cc, Neanderthal about 1400 cc.
• Saying that the Neanderthals were modern humans. They were a separate form.

Remember these

• Dryopithecus (more ape-like) and Ramapithecus (more man-like): about 15 million years ago.
• Australopithecines: about 2 million years ago, East African grasslands, stone weapons, mainly fruit.
• Homo habilis: 650 to 800 cc, probably no meat. Homo erectus: about 1.5 million years ago, about 900 cc, probably ate meat.
• Neanderthal man: about 1400 cc, 100000 to 40000 years ago, buried the dead. Modern Homo sapiens: 75000 to 10000 years ago. Cave art about 18000 years ago. Agriculture about 10000 years ago.

Check yourself

Try each one on your own first. If you are stuck, open a hint. Then check with Show the answer.

1. Which of the two early primates of 15 million years ago was more man-like?

2. Give two facts that NCERT states about Homo erectus.

3. What did the Neanderthals do with their dead and with hides?

4. The brain capacity rises from 900 cc to 1400 cc. What is the percentage increase?

5. Arrange in time order: Neanderthal man, Homo habilis, Homo erectus, modern Homo sapiens.

References

• NCERT (2023). Biology, Textbook for Class XII, chapter 6.
• Reece J. B. et al. (2017). Campbell Biology, 11th edition, Pearson, chapter 34, the origin of humans.