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Science

Old and new species

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New species

New species can arise as a result of isolation. This is where two populations of a species become geographically separated. For example, Charles Darwin described speciationspeciation: The formation of new and distinct species in the course of evolution. of finches this way.

Darwin studied the wildlife on the Galápagos Islands (a group of islands on the equator, almost 1,000 km west of Ecuador). He noticed that the finches (songbirds) on the different islands were similar to each other.

However, the finches showed wide variationsvariation: Difference between individuals; distance from the norm in their size, beaks and claws from island to island - for example, their beaks were different depending on the local food source. Darwin concluded that, because the islands are so distant from the mainland, the finches that had arrived there in the past and had changed over time.

Darwin's drawings of the different heads and beaks he found among the finches on the Galapagos Islands

Darwin's drawings of the different heads and beaks he found among the finches on the Galapagos Islands

Other ways for speciation to happen - Higher tier

New species can also arise as a result of:

  • Genetic variation - where each population has a wide range of alleles that control their characteristics
  • Natural selection - where the alleles which help an organism to survive are selected in each population
  • Speciation - where the populations become sodifferent that successful interbreeding cannot happen anymore

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