Tag: darwin's theory of evolution

Questions Related to darwin's theory of evolution

Which of the following are necessary for evolution by natural selection to take place?
(i) Offspring resemble their parents more than other individuals in the population.
(ii) Differences among individuals exist and lead to different numbers of successful offspring being produced.
(iii) Individuals adjust their development depending on the environment
(iv) Every individual possess enormous fertility.

  1. (i) and (ii)

  2. (ii) and (iv)

  3. (i), (iii) and (iv)

  4. (iii) only


Correct Option: B
Explanation:

The theory of natural selection was proposed by Charles Darwin. It states that Natural selection is the process where organisms with favourable traits are more likely to reproduce. In doing so, they pass on these traits to the next generation. Over time this process allows organisms to adapt to their environment. Features which are necessary for evolution by natural selection to take place are 

a) Differences among individuals exist and lead to different numbers of successful offspring being produced.

b) Every individual possesses enormous fertility.
So, the correct answer is '(ii) and (iv)'

The diversity in the type of beaks of finches adapted to different feeding habits on the Galapagos Islands, as observed by Darwin, provides evidence for

  1. Intraspecific competition

  2. Interspecific competition

  3. Origin of species by natural selection

  4. Origin of species by mutation


Correct Option: C
Explanation:
Darwin during his famous voyage, observed that finches from various Islands of Galapagos had beaks of different sizes and shapes. He observed that this was due to adaptation to different available food types. He concluded that the ancestral finches on reaching different islands occupied all empty ecological niches in absence of competition and evolved into different species. This provides evidences for origin of species by natural selection.

So, the correct answer is 'Origin of species by natural selection'.

Given: 1= Natural selection; 2= Variations and their inheritance; 3= Survival of the fittest; 4= Struggle for existence.
According to Darwinism, which of the following represents the correct sequence of events in the origin of new species?

  1. $3, 4, 1, 2$

  2. $2, 3, 1, 4$

  3. $1, 2, 3, 4$

  4. $4, 2, 3, 1$


Correct Option: D
Explanation:

  1.  There is a struggle for existence, because of the disparity between the number of individuals produced by reproduction and the number that can survive.
  2. Individuals within a species show variation; no two individuals are exactly alike. Those with advantageous characters have a greater probability of survival, and therefore of reproducing, in the struggle for existence.
  3. Individuals produce offspring that tend to resemble their parents (the principle of inheritance). Provided that the advantageous characters that promote survival are inherited by offspring.
  4. The offspring that evolve according to the condition are fittest for survival.
  5. Those are selected by nature and weaker ones got eliminated.
So the correct option is '4,2,3,1'

Naturalist who sailed round the world in ship Beagle was :

  1. Charles Lyell

  2. Charles Darwin

  3. Alfred Wallace

  4. Lamarck


Correct Option: B
Explanation:

  • Darwinism is an evolutionary theory proposed by Charles Robert Darwin, an English Naturalist. He believed that evolution is a gradual, rather than a sudden biological event. His theory was based on several facts, He sailed round in Beagle, his ship observations and inferences. They are 1) overproduction, 2) constancy in population, 3) struggle for existence, 4) natural selection.
  • The prodigality of production or overproduction: Every organism tends to increase its population in large proportions. For example, Paramecium divides by binary fission at the rate of three to four times a day. At this rate, the volume of all the paramecia equals to 10,000 times that of the earth at the end of the 9000th generation in the absence of any check.
  • Constancy in population: However, such an abnormal increase is not noticed in the population of any species in nature as the offspring die in large number before reaching the reproductive age. It is true that the food and the other sources do not increase in the same proportion as that of the population.
  • Struggle for existence: As the food sources are limited, severe competition exists among the members of a population. Darwin called it a struggle for existence.
  • Natural selection: The organisms with less reproductive success are not represented in future generations, however, fit they may be in the struggle for existence. This is called the Natural selection. Herbert Spencer called this phenomenon Survival of the fittest.
  • Darwinism failed to explain the mechanism by which variations occur. Thus Darwin faced the criticism "DARWINISM EXPLAINS THE SURVIVAL OF THE FITTEST BUT NOT THE ARRIVAL OF THE FITTEST".
So, the correct option is ' Charles Darwin'.

Darwin wrote "Origin of Species" in

  1. 1530

  2. 1795

  3. 1859

  4. 1895


Correct Option: C
Explanation:

  • Darwinism is an evolutionary theory proposed by Charles Robert Darwin, an English Naturalist. He believed that evolution is a gradual, rather than a sudden biological event. His theory was based on several facts, observations and inferences. They are 
1) overproduction
2) constancy in population
3) struggle for existence
4) natural selection.
  • The prodigality of production or overproduction: Every organism tends to increase its population in large proportions. For example, Paramecium divides by binary fission at the rate of three to four times a day. At this rate, the volume of all the paramecia equals to 10,000 times that of the earth at the end of the 9000th generation in the absence of any check.
  • Constancy in population: However, such an abnormal increase is not noticed in the population of any species in nature as the offspring die in large number before reaching the reproductive age. It is true that the food and the other sources do not increase in the same proportion as that of the population.
  • Struggle for existence: As the food sources are limited, severe competition exists among the members of a population. Darwin called it a struggle for existence.
  • Natural selection: The organisms with less reproductive success are not represented in future generations, however, fit they may be in the struggle for existence. This is called the Natural selection. Herbert Spencer called this phenomenon Survival of the fittest.
  • He wrote Origin of Species including these points in 1859.
So, the correct option is '1859'.

Charles Darwin discovered the law of independent assortment.

  1. True

  2. False


Correct Option: B
Explanation:
  • The law of independent assortment was given by Mendel. He also gave the 'Law of Dominance' and 'Principle of Segregation'.

Charles Darwin concluded that 

  1. Existing living forms share similarities to varying degree not only among themselves but also with the life forms that existed millions of years ago.

  2. These has been gradual evolution in the life forms on earth.

  3. Those organism, who are better fit in an environment leave more progeny that others. These therefore, will survive more and hence are selected by nature

  4. All the above


Correct Option: D
Explanation:

The Darwin theory of natural selection can be concluded as :

1. The number of organisms are produced more than that can survive because of limited resources.
2. Organisms struggle for the necessities of life; there is competition for resources.
3. Individuals within a population vary in their traits; some of these traits are heritable.
4. Some variants are better adapted to survive and reproduce under local conditions than others.
5. Better-adapted individuals are more likely to survive and reproduce, thereby passing on copies of their genes to the next generation.
6. Species whose individuals are best adapted survive while others become extinct.
So, the correct option is 'All of the above'.

Darwin's theory of natural selection to explain organic evolution was based on?

  1. Inheritance of acquired character

  2. Appearance of sudden large inheritable variation

  3. Modification of organs through use and disuse

  4. Prodigality of reproduction, struggle for existence and survival of the fittest


Correct Option: D
Explanation:

Darwin's theory of natural selection explains organic evolution as follows : 

1. The number of organisms are produced more than that can survive because of limited resources.

2. Organisms struggle for the necessities of life; there is competition for resources.
3. Individuals within a population vary in their traits; some of these traits are heritable.
4. Some variants are better adapted to survive and reproduce under local conditions than others.
5. Better-adapted individuals are more likely to survive and reproduce, thereby passing on copies of their genes to the next generation.
6. Species whose individuals are best adapted survive while others become extinct.


So, the correct option is 'Prodigality of reproduction, struggle for existence and survival of fittest'.

Darwin

  1. Believed that organisms could pass on acquired changes to offspring

  2. Worked out the mechanism of evolution by natural selection

  3. Was the first person to realize that organisms can evolve

  4. Was eager to publish his theory so that he could get all the credit


Correct Option: B
Explanation:
Charles Darwin was born in 1809. In 1831, he accepted an unpaid post of naturalist on a survey ship in which he spent five years in sea charting the East Coast of South America. During his five-week stay on Galapagos island, he noticed characteristic distribution of species of finches. After collecting a lot of information, Darwin began to realise that under the conditions of intense competition between members of a population, any variation that favours survival in a particular environment, would increase the ability of the individual to reproduce and leave fertile offspring. The variations which are less favourable would decrease the chances of survival of the individual. With this data, Darwin formulated a theory of evolution by 'natural selection' in 1839.
So, the correct answer is 'Worked out the mechanism of evolution by natural selection'.

The theory of evolution proposed by Charles Darwin is known as ________.

  1. Theory of natural selection

  2. Synthetic theory of evolution

  3. Lamarckism inheritance

  4. All of the above

  5. None of the above


Correct Option: A
Explanation:
The theory of evaluation proposed by Charles Darwin is known as theory of natural selection. It considers natural selection as one of the basic mechanisms of evolution, which is the gradual change in the trait of an organism by which organisms better adapted to their environment tend to survive and produce more offspring and the individuals that are poorly adapted to their environment are less likely to survive and reproduce, may become extinct.
So, the correct option is 'Theory of natural selection'.