Natural and Artificial Selection PDF

Flower color in plants, beak shape in birds, and eye color in animals. Have you ever wondered where these traits come from? The processes of natural and artificial selection play a major role in the development and display of these traits in many organisms. The British naturalist Charles Darwin help...

Flower color in plants, beak shape in birds, and eye color in animals. Have you ever wondered where these traits come from? The processes of natural and artificial selection play a major role in the development and display of these traits in many organisms. The British naturalist Charles Darwin helped develop the theory of natural selection based on his scientific work in the early 1800s. Darwin’s theory states that all species evolve (or change) over time, depending on what traits they need to survive. In his work, Darwin visited the Galapagos Islands, a group of small islands off the coast of South America. There, he found little birds called finches. Though the finches lived on several different islands, no two islands’ finches looked the same. The greatest variation between each island’s finches was the size of the birds’ beaks. Darwin predicted that originally there had been only one species of finch in the Galapagos, and as time went on, the beaks of the birds adapted to the particular food sources on each island. Finches with the beak size best-suited to the food available on each island continued to survive and reproduce on that island. Birds with beak sizes that were too small or too large for the available food sources died out. This pattern of island-specific adaptation led to different species of finches on each island. Natural selection is an important process in nature because it ensures the survival and reproduction of organisms that are best adapted to their environment. Organisms with traits that are not helpful die or relocate to an area where they can survive. However, nature is not the only authority that can select genetic traits in organisms. Humans can select traits for some organisms! Have you ever bought a puppy from a breeder? Often, people choosing a puppy seek a particular trait like curly fur, large size, or brown eyes. Breeders take the most desired traits into consideration when putting together breeding pairs. This allows the breeder to produce more puppies that display the most favored traits and will sell readily for good prices. This type of selection for traits is known as artificial selection or selective breeding. Whether determined by natural or artificial selection, the variety of traits displayed among organisms on Earth is fascinating! Collage by Kiwi Rex. File:Geospiza magnirostris - Hessisches Landesmuseum Darmstadt - Darmstadt, Germany - DSC00101.jpg by Daderot. File:Geospiza fortis.jpg by putneymark[1]. File:Certhidea olivacea.jpg by RajShekhar. File:Camarhynchus parvulus - Hessisches Landesmuseum Darmstadt - Darmstadt, Germany - DSC00091.jpg by Daderot, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=76752894 © Kesler Science, 2020