Note: I don’t know the year when your book was published so please just input it inside the parenthesis, change the ‘year published’. In the reference part just plug in the data for the year published, the place where it was published and the publisher. All of that information is in your book.
Natural Selection and Biodiversity
Darwin’s famous idea is the Theory of Natural Selection which he proposed in 1859 and which he stated in his published work, On the Origin of Species by Means of Natural Selection. The two main points in his study can be deduced from the title itself: first, organisms evolve (or they undergo “descent with modification”) and second, it happens through natural selection (Campbell et al, year published). The natural selection is a process wherein an organism will naturally ingrain capabilities and physical structures that is helpful for its survival. The subset of this idea is the famous phrase: the survival of the fittest. Darwin explained that all living organisms evolve or changes based on their physical conditions/environment and based on their successful competition against other species for resources they need. This theory of evolution explains that organisms adapt to their surroundings in order to live, thus whoever adapts the best survives.
Biological adaptation includes the change of an organism’s morphological features or phenotype. An organism’s phenotype is based on its genotype or its genetic composition. Biological adaptation is caused by environmental pressures that cause organisms to maintain or develop the caharacteristics that will help them survive. Such changes in an organism’s genotype, which will be manifested in its phenotype, are the beginning of speciation or the formation of new species different from its precursor. Therefore, natural selection is the explaination of our planets great biodiversity. In fact, the millions of organisms all over the world are all evolved descendants of the microbes that inhabited or primordial planet (Campbell et al, year published).
Because organisms need to adapt to their physical environment as well as compete with other organisms for vital resources such as food and mate, they evolve and change forming new species. A concrete example would be the speciation of pests. When a group of mosquitoes causing Malaria to millions of people were sprayed with pesticides, the first generation was more successfully elliminated than the subsequent ones (Campbell et al, year published). As the generation progresses, the pesticide became less and less effective because the mosquitoes have evolved to adapt to the pesticide. The members of the mosquito population who were carriers of enzymes that can destroy the pesticide survived and they were the ones who reproduced so that the next generations are already resistant to the specific pesticide formerly used (which in this case is DDT). This concrete example shows that through natural selection, because of the need to adapt, organisms are capable of evolving in order to survive.
Campbell et al (year published). Essential Biology with Physiology (2nd ed). Place Published: Publisher.