Based on observations made during the sea voyage on H.M.S. Beagle, Charles Darwin concluded that:
A. existing living forms share similarities to varying degrees with life forms that existed millions of years ago.
B. there had been extinctions of different life forms in the years gone by.
C. there has been sudden evolution of life forms in a single large step.
D. new forms of life arose at one single period of history of earth.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A and B only
On his voyage round the world on H.M.S. Beagle, Darwin compared living forms with each other and with those of the past. His conclusions challenged the theory of special creation.
A. existing living forms share similarities to varying degrees with life forms that existed millions of years ago. — True. Darwin found similarities not only among living forms but also with forms of the distant past.
B. there had been extinctions of different life forms in the years gone by. — True. Many life forms of the past do not exist any more.
C. there has been sudden evolution of life forms in a single large step. — False. Darwin concluded that there has been gradual evolution of life forms. Change in a single large step (saltation) was the later idea of de Vries.
D. new forms of life arose at one single period of history of earth. — False. New forms arose at different periods of the history of earth, just as extinctions took place over time.
So only A and B are correct.
NCERT Extract:
Evolution of Life Forms – A Theory – “… Based on observations made during a sea voyage in a sail ship called H.M.S. Beagle round the world, Charles Darwin concluded that existing living forms share similarities to varying degrees not only among themselves but also with life forms that existed millions of years ago. Many such life forms do not exist any more. There had been extinctions of different life forms in the years gone by just as new forms of life arose at different periods of history of earth. There has been gradual evolution of life forms.”