Evolution & Natural Selection

Natural Selection Watch the video and answer the following questions Matching Match each of the following terms with the definition on the right. artificial selection humans control how a species changes by selecting organisms with desirable traits to be the parents of the next generation natural selection Process through which traits in a population change over time as a result of some organism's abilities to survive and reproduce in their environment more often than others. genetic variation Differences in phenotypes among a species, usually caused by random mutations and environmental changes. evolution gradual change in a species over time adaptation A structure, physiological process, or behavior that makes organisms better able to survive and reproduce. Adaptation or Harmful Variation Read each example and decide if it is an example of an adaptation or a harmful variation. Sort into the correct group. Adaptation Deer mice that migrated to the sand hills of Nebraska changed from dark brown to light brown over time to better hide from predators in the sand. Sharks are colored white on the underside and blue or gray on the top. This is their camouflage as the top blends with the water color to someone looking down into the water and the bottom blends with the light coming through the water from above. Peacock females pick their mate according to the male’s tail. The ones with the largest and brightest tails mate more often. Today, most males have bright tails. Harmful Variation Dolphins in the ocean are typically grey; however, albino dolphins have a pink color. The Chernobyl nuclear disaster exposed living things to radiation which caused birth defects in humans and animals. Sickle cell anemia is a disease in which a person's body produces abnormally shaped red blood cells. The blood cells don't last as long as normal blood cells, and this leads to anemia. Sort the statements based on whether they describe selective breeding or natural selection. Natural Selection Organisms best adapted to their environment survive and reproduce more successfully than those that are less adapted Bacteria that develop a mutation that allows them to survive an antibiotic will live long enough to reproduce and so spread the 'survival' gene to subsequent generations Over a period of several thousand years the deer mice that live in the sandy soil of Nebraska developed a pale coat that helped them evade predators The angler fish lives in the deep, dark ocean and produces a light that attracts prey Populations of lizards that have a certain trait become more numerous after a change in climate Selective Breeding The intentional breeding of organisms by humans to produce organisms with desired characteristics The Belgian Blue cattle was created to be extremely muscular, therefore providing lots of beef Alaskan Sled dogs have been bred to be healthy and have endurance to run long distances Many varieties of tomatoes have been created to be different sizes, colors, tastes, and tolerant to different growing conditions Farmers allow only sheep that produce the best wool to breed Sort each statement based on whether it is an example of sexual or asexual reproduction. Sexual Reproduction Two parents contribute genetic information Each offspring is unique and genetically different from others Important source of genetic variation. Meiosis and fertilization are an important part of this process. Asexual Reproduction Involves only one parent Offspring are genetically identical to parent Examples are budding, vegetative propagation, and regeneration Can be a disadvantage in changing environments because the population lacks variation and can not adapt Which of the following factors is necessary in order for natural selection to occur in a species? genetic variation within a population an abundance of food resources a strong family structure none of the above