question_answer

(i) What is speciation?

(ii) How is Darwin's concept of evolution different from the views of Hugo de Vries?

Or

How do evidences support that evolutionary history of man is like that of any other organism?

Answer:

(i) Speciation is the formation of one or more new species from an existing species.
(ii) Differences between Darwin's concept and de Vries concepts are as follows
Darwin's concept	de Vries concept
Variations cause minor heritable changes in characters among the individuals of a species.	Mutations are large differences in the characteristics of organisms, that occur suddenly and cause speciation.
Evolution is gradual.	Evolution occurs in a large single - step mutation.
Or
It is a true and confirmed fact that evolutionary history of man is similar to that of any other organism. Following points support it.
(i) Evidences from fossils
(a) The Ramapithecus and Shivapithecus lived in Africa and Asia 14 - 15 mya were the forerunners of hominids (erect posture, bipedal locomotion).
(b) A genus, Australopithecus appeared in Africa about 5 mya and had a brain measuring\[350-4~50\,\,c{{m}^{3}}\].
(c) Genus Homo evolved about 2 mya.
(ii) Evidences from molecular studies Similarities in the sequence of blood proteins and nucleic acids indicate relationship of man with apes.
(iii) Evidences from chromosomal studies the banding pattern in chromosomal study of man and apes confirms the ancestral relationship between the two.
(iv) Evidences from haemoglobin The similarities in haemoglobin structure of man and ape indicate the relationship with apes and chimpanzee.