The correct sequence of human ancestors in increasing brain capacities.
a. Neanderthal man b. H. erectus
c. Cromagnon man d. H. habilis
e. Australopithecus

Answer

To determine the correct sequence of human ancestors in increasing brain capacities, we need to analyze the cranial capacities of each ancestor mentioned in the question. Here’s a step-by-step breakdown of the solution:

1. **Identify the cranial capacities of each ancestor**:
- Australopithecus: Approximately 500 cc
- Homo habilis: Approximately 650 to 800 cc
- Homo erectus: Approximately 900 cc
- Neanderthal man: Approximately 1300 to 1600 cc
- Cro-Magnon man: Approximately 1650 cc

2. **Arrange the ancestors based on their cranial capacities**:
- Start with the ancestor with the smallest cranial capacity and move to the one with the largest.
- From the data:
- Australopithecus (500 cc)
- Homo habilis (650 to 800 cc)
- Homo erectus (900 cc)
- Neanderthal man (1300 to 1600 cc)
- Cro-Magnon man (1650 cc)

3. **List the ancestors in increasing order of brain capacity**:
- The correct sequence is:
1. Australopithecus
2. Homo habilis
3. Homo erectus
4. Neanderthal man
5. Cro-Magnon man

Thus, the final answer is:
**e. Australopithecus, d. Homo habilis, b. Homo erectus, a. Neanderthal man, c. Cro-Magnon man.**