The Voyage of the BeagleOn the Origin of SpeciesThe Descent of Man, and Selection in Relation to Sex

Darwin’s greatest contribution to science is that he completed the Copernican Revolution by drawing out for biology the notion of nature as a system of matter in motion governed by natural laws. With Darwin’s discovery of natural selection, the origin and adaptations of organisms were brought into the realm of science.

Charles Robert Darwin was born into a wealthy family on February 12, 1809 in the town of Shrewsbury, England, UK. Robert Darwin had grown rich by shrewdly investing money earned from his medical practice.

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Darwin wrote that it was “indescribable.” That’s saying a lot, considering how many other animals he could compare it to. Darwin became a naturalist by way of beetle collecting, and it wasn’t unusual for him, even in his teen years, to try eating the beetles he picked up.

23 years

Charles Darwin’s theory of evolution states that evolution happens by natural selection. Individuals in a species show variation in physical characteristics. As a consequence those individuals most suited to their environment survive and, given enough time, the species will gradually evolve.

So main theories of evolution are: (II) Darwinism or Theory of Natural Selection. (III) Mutation theory of De Vries. (IV) Neo-Darwinism or Modern concept or Synthetic theory of evolution.

There are four principles at work in evolution—variation, inheritance, selection and time. These are considered the components of the evolutionary mechanism of natural selection.

• Vitalism.
• Theistic evolution.
• Orthogenesis.
• Lamarckism.
• Catastrophism.
• Structuralism.
• Saltationism, mutationism.
• Genetic drift.

Although Darwin’s theory of natural selection was basically correct, in the late 1860s he proposed a theory that was very wrong. That theory—”pangenesis”—was an attempt to explain variation among individuals in a species. Offspring in sexual species display a mix of traits from both of their parents.

Ernst Mayr observed, “The basic theory of evolution has been confirmed so completely that most modern biologists consider evolution simply a fact.

Contrary to popular belief, not only are humans still evolving, their evolution since the dawn of agriculture is faster than ever before. For example, while human DNA is on average 98% identical to chimp DNA, the so-called Human Accelerated Region 1 (HAR1), involved in the development of the brain, is only 85% similar.

The basic rationale behind the conclusion that human evolution has stopped is that once the human lineage had achieved a sufficiently large brain and had developed a sufficiently sophisticated culture (sometime around 40,000–50,000 years ago according to Gould, but more commonly placed at 10,000 years ago with the …

Firstly, humans did not evolve from monkeys. Instead, monkeys and humans share a common ancestor from which both evolved around 25 million years ago. This evolutionary relationship is supported both by the fossil record and DNA analysis. A 2007 study showed that humans and rhesus monkeys share about 93% of their DNA.

5 to 8 million years ago. Shortly thereafter, the species diverged into two separate lineages. One of these lineages ultimately evolved into gorillas and chimps, and the other evolved into early human ancestors called hominids.

Homo erectus