Darwin realized the importance of the finches after leaving the islands while he was studying specimens he brought back with him. The trait he noticed was the differences in the size and shape of the finches beaks. He theorised that new species will arise when some factor causes a population to be divided.

Darwin noticed that fruit-eating finches had parrot-like beaks, and that finches that ate insects had narrow, prying beaks. Later, Darwin concluded that several birds from one species of finch had probably been blown by storm or otherwise separated to each of the islands from one island or from the mainland.

On his visit to the Galapagos Islands, Charles Darwin also discovered several species of finches that varied from island to island, which helped him to develop his theory of natural selection. Today, there are a total of 14 of which make up the group known as Darwin’s finches.

The Galápagos Islands finches display a wide variety of beak shapes and sizes. The beaks of this isolated group of birds have evolved to match their niche diets and were an important clue for Charles Darwin in developing his theory of evolution. This bird has a long, spike-shaped bill that tapers to a point.

Darwin’s theory of evolution by natural selection was considered dangerous in 19th-century England because it threatened the prevailing views of the Anglican Church and society at large. Evolution can seem to be in direct conflict with deeply held belief systems of how life came to exist on Earth.

Beginning in 1837, Darwin proceeded to work on the now well-understood concept that evolution is essentially brought about by the interplay of three principles: (1) variation—a liberalizing factor, which Darwin did not attempt to explain, present in all forms of life; (2) heredity—the conservative force that transmits …

One of the more important evolutionary concerns facing humans today is the continual evolution of antibiotic-resistance in bacteria. Similarly, the use of pesticides in agriculture has driven the evolution of resistant insects, requiring the use of harsher chemicals in greater quantity to kill them.

Numerous examples of this human-induced contemporary evolution have been reported in a number of ‘contexts’, including hunting, harvesting, fishing, agriculture, medicine, climate change, pollution, eutrophication, urbanization, habitat fragmentation, biological invasions and emerging/disappearing diseases.

Humans are inherently social. We are not special in this way; it is hard to think of any animal for whom the regulation of social behaviour is not important. Something akin to social behaviour may even occur in organisms lacking a nervous system.

The five theories were: (1) evolution as such, (2) common descent, (3) gradualism, (4) multiplication of species, and (5) natural selection. Someone might claim that indeed these five theories are a logically inseparable package and that Darwin was quite correct in treating them as such.

There are five lines of evidence that support evolution: the fossil record, biogeography, comparative anatomy, comparative embryology, and molecular biology.

Fossils are the imprints or remains of organisms which were alive millions of years ago. The fossil record provides evidence for evolution . Charles Darwin’s theory states that all organisms alive today evolved from more simple life forms. Two fossils named Ardi and Lucy provide evidence for human evolution.

Five types of evidence for evolution are discussed in this section: ancient organism remains, fossil layers, similarities among organisms alive today, similarities in DNA, and similarities of embryos.

Mutation plays an important role in evolution. The ultimate source of all genetic variation is mutation. Mutation is important as the first step of evolution because it creates a new DNA sequence for a particular gene, creating a new allele.