Accumulation of the fittest phenotypic variations within individuals is the main driving force of speciation according to Darwin. Therefore, natural selection is the survival of the fittest in the environment.
On the other hand, Neo Darwinism is a modified theory of Darwinism, describing the origin of species according to a genetic basis. Thus, genetic variations are the major driving force of Neo Darwinism. Here, natural selection is based on the differential selection of fittest genes within a gene pool.
Accordingly, the main difference between Darwinism and Neo Darwinism is the type of variations and type of natural selection. Noble, Denis. Figure 1: Human Evolution. Figure 2: Neo Darwinism. Thus, Darwinism and Neo Darwinism are important landmark theories in an attempt to explain evolution, but they both carry significant similarities and differences.
Given below is an appropriate definition of Darwinism and Neo Darwinism:. Darwinism describes that favourable phenotypic variations which can be inherited are the major cause of speciation. These favourable phenotypic variations get accumulated over certain amounts of time.
Neo Darwinism describes that the only inheritable genetic variations such as mutations are the major cause of speciation. These genetic variations can be sudden and bring about large changes in a population.
After having known about the definitions of Darwinism and Neo Darwinism, it will be clear to you that both theories have fundamental similarities and differences. Let us have a look at it. Darwinism and Neo Darwinism theory depict the cause of the theory of natural selection and a legitimate step in understanding evolution itself. Following are the similarities between the theories:. Both the theories are an important step towards explaining speciation and the driving forces behind it.
Both the theories explain the process of evolution amongst the organisms. Both the theories are heavily dependent upon the cause of speciation as variation be it phenotypic or genotypic but ultimately a variation in the biological characteristics of the organism of a species.
See the open-access textbook Concepts of Biology for more information about these lines of evidence. In the first edition of "On the Origin of Species," published in , Darwin speculated about how natural selection could cause a land mammal to turn into a whale. As a hypothetical example, Darwin used North American black bears Ursus americanus , which were known to catch insects by swimming in the water with their mouths open.
The idea didn't go over very well with the public or with other scientists. Darwin was so embarrassed by the ridicule he received that the swimming-bear passage was removed from later editions of the book. Scientists now know that Darwin had the right idea but the wrong animal. Instead of looking at bears, he should have been looking at cows and hippopotamuses. The story of the origin of whales is one of evolution's most fascinating tales and one of the best examples scientists have of natural selection.
To understand the origin of whales, you need a basic understanding of how natural selection works. Natural selection can alter a species in small ways, causing a population to change color or size over the course of several generations. When this process happens over a relatively short period of time and in a species or small group of organisms, scientists call it "microevolution.
But when given enough time and accumulated changes, natural selection can create entirely new species, a process known as "macroevolution. Take the example of whales: By using evolution as a guide and understanding how natural selection works, biologists knew that the transition of early whales from land to water occurred in a series of predictable steps.
The evolution of the blowhole, for example, might have started with random genetic changes that resulted in at least one whale having its nostrils farther back on its head. The whales with this adaptation would have been better suited to a marine lifestyle, since they would not have had to completely surface to breathe.
Such individuals were more successful and had more offspring. In later generations, more genetic changes occurred, moving the nose farther back on the head.
Other body parts of early whales also changed. Front legs became flippers. Back legs disappeared. Their bodies became more streamlined, and they developed tail flukes to better propel themselves through water.
Darwin also described a form of natural selection that depends on an organism's success at attracting a mate — a process known as sexual selection. The colorful plumage of peacocks and the antlers of male deer are both examples of traits that evolved under this type of selection. But Darwin wasn't the first or only scientist to develop a theory of evolution.
The main difference between Darwinism and evolution is that D arwinism is a theory of evolution based on natural selection whereas evolution is the change in the genetic composition of a population over successive generations.
Darwinism describes organic evolution, which results in speciation. But, evolution is driven by natural selection, gene flow , genetic drift , inbreeding, hybridization or mutation. Darwinism and evolution bring phenotypical changes in the individuals of a particular population with time. Both occur in response to the long-term changes of the environment. What is Darwinism — Definition, Features, Examples 2.
What is Evolution — Definition, Features, Examples 3. Darwinism refers to the theory of evolution of species by natural selection advanced by Charles Darwin. Natural selection is one of the main mechanisms that drive evolution. It aids the individuals of a particular population to adapt well to their environment.
This gives them a better chance at survival and the ability to produce more offspring within that environment.
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