EXERCISES

Q1. In which geological period man appeared on this earth?
Answer: Man appeared on this earth in the Quaternary geological period.

Q2. Who discovered the fossil remains of Java man? They belong to which geological period?
Answer: The fossil remains of Java man (Pithecanthropus erectus) were discovered by a Dutch doctor, Eugene Dubois, at Trinil on the bank of the river Solo in Java in the year 1891. The geological age of the Pithecanthropus finds are certainly early Pleistocene, but some are of the opinion that these belong to the late Pliocene.

Q3. Write three characteristic features of Cro-Magnon man.
Answer: Three characteristic features of Cro-Magnon man are: The skull is large. The forehead is vertical. The chin is prominent. The long bones suggest great heights.

Q4. Write briefly on organic evolution.
Answer: Organic evolution is the gradual change and development of simple and lower categories of life forms to more complex and higher categories of life forms in consequence of the geo-environment. Life originated once on earth as a minute simple cell organism, which became complicated and multicellular through a long and continuous process of change and adaptation to the changing atmosphere.

Q5. Write briefly on human evolution.
Answer: The process of human evolution can be traced passing through the stages of Australopithecine, Homo erectus, Homo Neanderthal, and Homo Sapience. The Cenozoic era, particularly the Quaternary epoch, is marked by the evolution of man from its simplest to complex types. Discoveries of fossil apes and hominids like Ardipithecus have helped in reconstructing this past.

Q6. From where fossil remains of Neanderthal man is discovered?
Answer: The remains of Neanderthal man were first discovered in the year 1856 in the Neanderthal valley near Dusseldorf, Germany.

Q7. Write shortly on Neanderthal man.
Answer: Neanderthal man flourished during the great ice age. They were able to exploit the environment to create a cultural perspective of their own, which is named Mousterian culture and corresponds to the Middle Palaeolithic period. The typical implements were scrapers and points. They were cave dwellers, formed larger social units, and buried their dead, suggesting a religious concept. They have been divided into conservative and progressive categories.

Q8. Write the names of two books written by Charles Darwin.
Answer: Two books written by Charles Darwin are On the Origin of Species by Means of Natural Selection (published in 1859) and The Descent of Man (published in 1871).

Q9. Who discovered the fossil remains of Australopithecus Africanus?
Answer: The first of the australopithecine group, Australopithecus africanus, was brought into light by an Australian born anatomist, Prof. Raymond Dart, in the year 1924 at Taungs in Bechuanaland, South Africa.

Q10. Who discovered the fossil remains of Pithecanthropus erectus? Why are they termed as Homo erectus?
Answer: The fossil remains of Pithecanthropus erectus were discovered by a Dutch doctor, Eugene Dubois, at Trinil on the bank of the river Solo in Java in the year 1891.
They are termed Homo erectus because some members of the family Australopithecine and Habilis evolved into the big-brained genus Homo erectus. This genus is differentiated by possessing an increased cranial volume, which is higher than that of Australopithecines and Homo habilis.

Q11. Which fossil man is considered as Homo sapiens? Write four characteristic features of that fossil man.
Answer: Cro-Magnon man was among the first to be recognized as belonging to our own species, Homo sapiens.

Characteristic features of Cro-Magnon man:

1. The skull is large.
2. The forehead is vertical.
3. The chin is prominent.
4. The long bones suggest great height.

Q12. What are the two types of Neanderthal man?
Answer: According to Hooton, Neanderthal people are divided into two categories:

1. Conservative Neanderthal
2. Progressive Neanderthal

Q13. Who is Lamarck? Discuss the theory of Lamarckism.
Answer: Jean Baptiste de Lamarck (1744–1829) was a French naturalist who presented the first persuasive theory of evolution.

The theory of Lamarckism, also called the “Theory of Inheritance of Acquired Characters,” centers around the idea that physical changes occurring in an individual during its lifetime are inherited by its offspring.

Lamarck’s four laws are :

1. Life tends to change continuously to increase in volume and size.
2. A new need leads to the development of a new organ.
3. Use and disuse of organs cause their development or degeneration.
4. Acquired characters are transmitted to the next generation and become hereditary.

Q14. Discuss Darwin’s theory of natural selection.
Answer: Darwin’s theory of natural selection is based on the following principles:

1. Overpopulation: Every organism produces more offspring than can survive, while food and resources remain limited.
2. Struggle for existence: Due to competition for limited resources, a struggle occurs among members of the same species, among different species and with the  surroundings
3. Natural selection (Survival of the fittest):
   Organisms with beneficial variations survive, while those with unfavorable ones are eliminated by nature.
4. Origin of new species:
   A new species arises through the gradual accumulation of favorable variations, selected and inherited over generations.
5. Variation and heredity:
   Favorable traits are inherited and passed to future generations, promoting evolutionary progress.

Q15. Write the synthetic theory of evolution.
Answer: The Synthetic Theory of Evolution is the modern theory that combines Darwin’s ideas with modern knowledge from genetics, population dynamics, statistics, and heredity.

It explains evolution as the result of genetic changes within populations that lead to the formation of new species.

Major concepts included are :

1. Genetic variations
2. Reproductive and geographical isolation
3. Natural selection

Main evolutionary factors are :

1. Genetic recombination
2. Mutation
3. Natural selection
4. Genetic drift
5. Gene flow
6. Isolation

Q16. What are the different mechanisms of evolution?
Answer: Discuss. The mechanisms of evolution that change the frequencies of traits in populations are:

1. Mutation: A sudden change in the genetic material (DNA) of an organism, resulting in new heritable traits and variation.
2. Genetic Drift: A change in the gene pool of a small population by chance (also called the Sewall Wright effect).
3. Gene Flow: The movement of genes between populations through migration, increasing variability and altering allele frequencies.
4. Natural Selection: The process by which advantageous traits become more common as species adapt to their environment.
5. Inbreeding: A non-random mating process where closely related individuals reproduce. While it does not directly change allele frequencies, it increases homozygosity and affects population genetics indirectly.