An Overview On The Origin Of Species

When we started learning about science we heard about the word organisms. Later on, diving deep into the subject we got to know about Charles Darwin and his famous book named On The Origin Of Species, It is of the utmost importance in the history of science. But before knowing about what he wrote in his book let us know more about the author Charles Darwin. 

Who is Charles Darwin – A brief history :

Charles Darwin’s full name Charles Robert Darwin. He was an English naturalist on February 12, 1809, at Shropshire, England. His research on the scientific theory of natural selection has evolved into the foundation of contemporary evolutionary studies. Charles Darwin stunned pious Victorian society when he proposed that humans and animals shared a similar ancestor. His nonreligious biology, on the other hand, drew the attention of an upcoming class of scientists, and by the time he died, evolutionary imagery had spread throughout science, literature, and politics. After returning from a voyage around the world aboard the HMS Beagle in1837–39, Darwin formulated his bold theory in private, but it was not until two decades later that he gave it complete freedom of expression on “On the Origin of Species”(1859), a book that has profoundly influenced modern Western society and thought.

Origin of species

Variation under domestications:

In the first chapter, Darwin begins his point of view on natural selection by addressing the widely held belief that changes in species can be present at the organism level. It also states that changes in an individual that occur during an organism’s lifetime, cannot be passed down to their offspring. He states that sexual reproduction is the only form of natural selection. Darwin discusses domesticated animals’ ability to revert to their pre-domesticated state. He also claims that reverting domestic races or breeds are all members of the same species.

Variation under nature :

Darwin begins the second chapter by explaining some of the terms he has introduced in the first chapter. Darwin dedicates this chapter in distinguishing the different types of species and their varieties.

Struggle for existence:

After he attempted to define the various species, Darwin shifted his attention to what he sees as the driving force behind natural selection in wild animals—the struggle for survival. It is simply a struggle for survival because it affects an organism and its potential for offspring, thereby affecting a species on a population level. Darwin describes several methods for keeping a population in check, including the proclivity for death in young or juveniles, the ability to obtain food or be food for another species, climatic effects, and epidemics. It is due to this competition that subtle variations occur, resulting in the formation of distinct species.

Natural selection:

Charles Darwin explains how the idea of natural selection may be applied to both tamed and wild animals in this chapter. Natural selection, or survival of the fittest, is defined by Darwin as the “preservation of advantages about the individual differences and the variations, and the eradication of those which are harmful.” He begins his argument by stating that environmental change causes species variety. The likelihood of a great degree of variety is aided by the correlation of characteristics, which means that a small change in one trait leads a comparable change in another.

Laws of variations 

Charles Darwin’s concern in Chapter 5 is to describe the rules of variation. He starts by pointing out that environmental factors, like food and climate, have a role in variation and, most likely, natural selection. The extent of this role, however, is unknown. He claims that natural selection is influenced by the certain amount of usage or disuse of a part. After that, Darwin discusses the variation in secondary sexual traits. Within the same species, there may be a lot of variety in these qualities, and an independent species might develop similar traits.

Difficulties on theories:

The purpose of Chapter 6 in Charles Darwin’s book On The Origin Of Species is to examine the potential objections in his theory of natural selection. Darwin contends that the lack of transitory variants of species is due to a lack of time depth. He then responds to the claim that certain species’ structures are the consequence of beauty selection. He claims that determining what is beautiful is necessarily subjective.

Instinct:

This chapter of On the Origin of Species is devoted to answering problems brought by scientists in previous editions of the book, this one being the latest. It is clear Darwin is attempting to stave off future critics and solidify his theory of natural selection Many paleontologists, on the other hand, have differentiated species based on minor traits found in a small number of ancient specimens.. However, he argues his critics’ objections are based on flawed logic.

Hybridism:

Darwin presents the idea that natural selection influences not just physical qualities but also instincts in this chapter. He doesn’t explain instinct, but equates it to habits, claiming that his readers understand what he’s talking about when he starts using the term.

On the imperfection of the geological record 

While Darwin admits he doesn’t know how long it takes for a new species to generate, he argues it’s longer than the time depth reflected in many geological strata. He mentions how difficult it is for naturalists to tell the difference between species and variations in extant organisms. Many paleontologists, on the other hand, have differentiated species based on minor traits found in a small number of ancient specimens.

On the geological succession of organic beings

The process of species extinction is then discussed by Darwin, who claims that catastrophism has been “generally given up” by contemporary geologists. Rather, the extinction of species is thought to be a process that is as slow as, if not slower than, the development of species. Darwin then goes on to explain how change appears to happen at the same moment all across the earth over lengthy periods of time. Natural selection and the spread of species across the planet over time, he claims, can explain this process.

Geographical distribution 

The remainder of the chapter is devoted to discussing a few means of dispersal, including climate, land and sea level changes, continental shifts, and glacial eras. He adds a few more observations about species biogeography, observing that species travelling north to south are more likely to adapt to the region than those moving south to north.

About affinities:

He points out that despite marine barriers that appear to be impenetrable, freshwater systems in different countries can sometimes include extremely similar freshwater species. 

Recapitulation and Conclusion:

Darwin notes in the final chapter that the book has been “one long debate,” and that his purpose is to synthesise the arguments in order to persuade the reader of the full strength of his case. He then goes over some of the counter-arguments to the theory of natural selection, emphasising that “they are by no means adequate to topple” the theory of natural selection in any event.

Conclusion:

Darwin’s work popularised the scientific concept of natural selection, which states that populations evolve over generations. The book presented evidence that life’s diversity emerged from common descent through a branching evolutionary pattern.