Many have tried to understand the phenomenon behind evolution. Many have tried to become a great detective and find answers about how evolution is occurring. Darwin has thought that the origin of species is a “mystery of mysteries.” Darwin and Wallace have been investigating these mysteries and somehow they have the same general conclusion. Even though Darwin had imperfect abstract about this topic, he sought for answers and finally introduced us his point. He even emphasized “natural selection.” This also under Malthus’ doctrine – that as many more individuals of each species are born than can possibly survive and struggle for existence, however, slightly in any manner profitable to itself in varying conditions of life will have a better chance of surviving, thus be naturally selected. Thus, this “natural selection” could almost inevitably cause much extinction to less improved and incapable forms of life leading to divergence of the character, but ever since, this topic was only considered a theory and a very sensitive topic to talk about. He considers himself a naturalist, in a way that he reflects on scientific way of observing and thinking. Dawkins somehow same and approved Darwin’s ideas would reflect on recent issues about evolution. Thus, he would say that the concept of evolution also changes over time. Even though religion and science would normally clash, religion and science must not interfere with each other because it may venture confusion. Evolution is a fact. It is right to know about anything that has a proof but it would depend on you on how you would absorb it. Evolution has now been proven but still lacking more evidences. In platonic idea, an organism of today may be an organism of the past but with different appearance, which in recent they evolved in a perfect way (though may still be imperfect) they could fit and survive in their environment. Darwin believes that natural selection is a an exclusive means of evolution.
What would be the causes of this variability among species? Variation under domestication would further affect the gene pool. Selective breeding affects not only the appearance but also the DNA content that would flourish into certain species. Variation can also occur through correlation. Varied changes in the embryo or larva will probably had an effect and thus changes the mature animal. Hybridization on the other hand would represent a deliberate violation of the isolation of the gene pools. This hybridization would incur mutations. Mutations are the random changes in genes that constitute the raw material for evolution by non-random selection. It occurs naturally in nature but large mutations seldom survive. A mutation is just a light increment or decrement in the numerical value of the parent’s gene. Dawkins produced a game that would illustrate artificial selection. He emphasized that a single mutation typically has an effect all over the whole organism, rather than just in one part of it. Humans on the other hand, used their senses to selectively breed animals or plants making many varieties of each. But it is of human nature to make choices and plan for the better. Before humans, being a domesticator, insects are the first ones to domesticate not animals but flowers. Like humans, insects also used their senses in picking flowers that would be capable of what would they need. Again these observations would lead to natural selection process. Thus, also I can conclude that variation would occur through natural selection that would therefore produce mutation. Darwin also emphasizes that choice can be made automatically by survival or not surviving. Survival counts, Darwin realized, because only survivors reproduce and pass on the genes that helped them to survive. Without any kind of choosing agent, those individuals that are ‘chosen’ by the fact that they are chosen because they happen to possess superior equipment to survive are the most likely to reproduce, and therefore to pass on the genes for possessing superior equipment. Therefore every gene pool, in every species, tends to become filled with genes for making superior equipment for survival and reproduction. Natural selection on the other hand is related to the “survival of the fittest.” Since, Darwin’s theory must be proven, an experiment must be performed to answer the hypothesis. To test the hypothesis, an experiment must be done. But this selection is naturally occurring in nature thus manipulation systematically must be done in order to perform natural selection as naturally as possible.
Finally, we can say that varieties cannot be distinguished from species. Except that we could distinguish varieties by the discovery of intermediate linking forms; and by a certain indefinite amount of difference between them. The amount of difference considered necessary to give to any two forms the rank of species cannot be defined. In genera having more than the average number of species in any country, the species of these genera have more than the average number of varieties. In large genera the species are apt to be closely but unequally allied together, forming little clusters round other species. Species very closely allied to other species apparently have restricted ranges. In all these respects the species of large genera present a strong analogy with varieties. And we can clearly understand these analogies, if species once existed as varieties, and thus originated; whereas, these analogies are inexplicable if species are independent creations. We have also seen that it is the most flourishing or dominant species of the larger genera within each class which on an average yield the greatest number of varieties, and varieties, as we shall hereafter see, tend to become converted into new and distinct species. Thus the larger genera tend to become larger; and throughout nature the forms of life which are now dominant tend to become still more dominant by leaving many modified and dominant descendants. But, by steps hereafter to be explained, the larger genera also tend to break up into smaller genera. And thus, the forms of life throughout the universe become divided into groups subordinate to groups.
Co-evolution on the other hand, also occurs between species that don’t benefit from each other’s presence, like predators and prey, or parasites and hosts. These kinds of co-evolution are sometimes called ‘arms races.’ I can say that based on Darwin’s explanations if variation under nature, this is also the “co-evolution.” Nature would be as a selecting agent. If a variety were to flourish so as to exceed in numbers the parent species, it would then rank as the species, and the species as the variety; or it might come to supplant and exterminate the parent species; or both might co-exist, and both rank as independent species. It is a complex relationship to each other in the struggle of existence. This would only indicate that if one is affected, its co-evolved species would also be affected.
In order to distinguish time these evidences that occurred many years before, there were processes or techniques scientists use. These are through the following: tree rings, radioactive dating, and position of rocks the fossils are obtained.
Natural selection would eventually modify an organism aiding it to be advantageous to its environment and would definitely opt to evolution. Natural selection could also be of sexual selection. This process is also naturally occurring in nature. This form of selection depends, not on a struggle for existence in relation to others or to external conditions, but on a struggle between the individuals of one sex, generally the males, for the possession of the other sex. The result is not death to the unsuccessful competitor, but few or no offspring. Those which are best fitted for their places in nature will leave most progeny. In nature, those who survive and have most progeny will survive. An example of this was emphasized on Dawkins, where there is an experiment on a bacteria, to which is easier to duplicate by just a day. He emphasized that a sufficiently high dose will kill all the bacteria while sufficiently low dose will kill none. An intermediate dose will kill some, but not all, there were still that will survive. If there is genetic variation among bacteria, such that some are more susceptible to the antibiotic than others, an intermediate dose will be tailor-made to select in favor of genes for resistance.
These are all happening slowly with the aid of nature. On the other hand, natural selection could also result to extinction of population of species. Having nearly the same structure, constitution and habits, generally come into the severe competition with each other. Consequently, each new variety or species, during the progress of its formation, will generally press hardest on its nearest kind, and tend to exterminate them. They have emphasized that the same process of extermination among our domesticated productions, through the selection of improved forms by man. Thus this would also result to divergence of characters. But there was this Darwin’s idea of convergence of character. Darwin emphasized that if two species belonging to two distinct though allied genera, had both produced a large number of new and divergent forms, it is conceivable that these might approach each other so closely that they would have all to be classed under the same genus; and thus the descendants of two distinct genera would converge into one. But it would in most cases be extremely rash to attribute to convergence a close and general similarity of structure in the modified descendants of widely distinct forms.
Thus this would be if under changing conditions of life organism’s present individual differences in almost every part of their structure, and this cannot be disputed; if there be, owing to their geometrical rate of increase, a severe struggle for life at some age, season or year, and this certainly cannot be disputed; then, considering the infinite complexity of the relations of all organic beings to each other and to their conditions of life, causing an infinite diversity in structure, constitution, and habits, to be advantageous to them, it would be a most extraordinary fact if no variations had ever occurred useful to each being’s own welfare, in the same manner as so many variations have occurred useful to man. But if variations useful to any organic being ever do occur, assuredly individuals thus characterized will have the best chance of being preserved in the struggle for life; and from the strong principle of inheritance, these will tend to produce offspring similarly characterized. This principle of preservation or the survival of the fittest which leads to the improvement of each creature in relation to conditions and organization of life, and those low and simple forms will long endure if well fitted for their simple conditions of life.
Again, even since there were evidences to prove evolution, there were still missing evidences that would further prove it. Fossil record is limited that some people tend to ask more. Gap in the fossil record was termed as a missing link between discovered and recent species. Evolution not only is a gradual process but it has to be gradual if it is to do any explanatory work. Molecular evidences have proven more of evolution. Little by little this gap is being filled also little by little.