Evolution and Biological Adaptation

Speciation is the term used for the development of new species by changes in population. Charles Darwin was the first to describe role of natural selection in speciation. Therefore, (b) is the correct answer.

• Charles Darwin proposed the theory of natural selection. It emphasized that in a population, variations result based on different combinations of traits and the carrying capacity of the environment is limited. 
• Hence there cannot be a guarantee of breeding and reproduction probability. In such a situation nature selects the best-adapted organisms for survival with better traits than the other.  
• Such an organism will have a greater chance of becoming parents for the next generation because of its superior characters. 
• So there is a struggle among the organisms for existence in which only the fittest organism survives and others perish. This concept is called as the survival of the fittest. Thus the correct answer is option C. 

Darwin notes that there is greater variation observed in domesticated species than would be seen in the wild. Darwin admits that the laws governing inheritance are not yet fully understood, why some traits might skip generations while others only appear in one sex or the other. He reviews a number of domesticated species, in particular various breeds of dogs where it remains unclear if they derive from a single parent species or several. After the different types of animals he has focused his study on domestic pigeons. So, the correct answer is "Breeding domesticated animals".

Thomas Malthus' work helped inspire Darwin to refine the natural selection by stating a reason for meaningful competition between members of the same species. Not surprisingly, Malthus, an ordained minister, believed that hunger and disease were aspects of life implemented by God to stop populations from exploding. Malthus was an influence through his book 'Essay on Population'

So, the correct answer is 'Origin of Species'

The main concept of Darwin's theory was natural selection. Other main points were High rate of reproduction, Total number almost constant, Struggle for existence, Variations, Survival of the fittest. It didn't had genetic drift. Hence, option C is correct.

In 1868, Darwin put forward the Theory of Pangenesis. According to this theory, every organ of the body produces minute hereditary particles, called gemmules or Pangenes, and they can be carried through the blood into the gametes. It laid emphasis on some basis of inheritance. Hence, Option A is correct. 

The main features of Darwin's theory of Natural Selection are as follows - 

The inheritance of acquired characters is the core of Lamarckism, not Darwinism. Darwin focused on natural selection acting on existing variations.

One of the major drawbacks of Darwin's theory is the absence of knowledge on inheritance. The genetic basis of evolution, cause of variations was not included in Darwin's 'Origin of Species'. It was only after the discovery of genes and traits by Mendel, genetics could be associated with evolution.

Darwin's Theory of Evolution states that groups of organisms will undergo genetic changes over time due to the process of natural selection. If enough changes occur, this can create new species from the pre-existing ones. Variations in a species' genetics that lead to evolution often come from mutations.

According to Darwin the evolution occurs due to adaptation of the species to the environmental conditions , these adaptations are then carried out to the next generation by reproduction thus the species survive and evolve 

The Charles Darwin's theory is based on the survival of the fittest , the species who readily adapt to the changes in the environment for its existence tend to live. The species fitting to the natural selection only survive