Selective Breeding vs. Natural Selection 7.11C identify some changes in genetic traits that have occurred over several generations through natural selection and selective breeding such as the Galapagos Medium Ground Finch (Geospiza fortis) or domestic animals. Natural Selection & Selective Breeding Goal: • I can explain natural selection in my own words. • I can explain selective breeding in my own words. • I can provide examples of natural selection & selective breeding. Natural Selection The process by which some individuals are better ADAPTED to their environment and are more likely to SURVIVE and reproduce than other members of the same species. ◦ Variation of a trait ◦ Competition ◦ Over production What is needed for natural selection to occur? 1. Variation in traits. For example, some beetles are green and some are brown. 2. Overproduction. Most species produce far more offspring than can possibly survive. Why? 3. There is competition. The members of a species must compete with one another to survive because food, space, and other resources are limited. End result: Since the brown beetles live longer, they have more offspring. The brown coloration becomes more common in the population. If this process continues, eventually, all individuals in the population will be brown. Natural Selection Example: Peppered Moth Can you see the moths? Example: Peppered Moths Manchester, England 1845. The trunks of the trees in the forest were light grayish-green due to the presence of lichens. Most of the peppered moths in the area were light colored with dark spots. Manchester, England from 1845 to 1890 As the industrial revolution progressed, the tree trunks became covered with soot and turned dark. Over a period of 45 years, the dark variety of the peppered moth became more common. Natural Selection Example: Galapagos Ground Finch In the 1850’s Charles Darwin observed finches on the islands for 5 years Galapagos Ground Finch Cont. Darwin discovered that there were many variations of one kind of bird, the finch. (difference in form of the same species) He noticed that there were finches with large beaks on some islands and finches with small beaks on other islands NATURAL SELECTION Discuss and be ready to share: • Define natural selection in your own words. • Describe some examples of natural selection discussed today. • Come up with your own examples of natural selection. Selective Breeding the process of selecting or choosing specific plants or animals to breed for particular desirable genetic traits typically, strains which are selectively bred are domesticated, and the breeding is sometimes done by a professional breeder Natural Selection vs. Selective Breeding Natural Selection Selective Breeding Change in genetic The mating of parent traits over time organisms by humans because of to produce desired environmental traits in the next factors generation • Organisms that are alive longer, have the opportunity to reproduce; • The more organisms that have a trait, the more likely it will be passed on to the next generation Domestic Animals Various animals that have been tamed and made fit for a human environment. SELECTIVE BREEDING Summary: Human Influence on characteristics and behavior. Domestic Animals ◦ Ex: Chickens, Dogs, Cows Plants: ◦ Ex: Corn, Brasilica, Fruit hybrids Cows are breed for particular traits… ◦ Dairy cow for milk production ◦ Raised as livestock for meat ◦ Strength for pulling a plow, no horns for safety, manure for fertilizer Why breed plants? higher-yielding (make more/bigger fruit) resistant to pests and diseases drought-resistant or regionally adapted to different environments and growing conditions Domestication of plants is an artificial selection process conducted by humans to produce plants that have more desirable traits than wild plants Undesirable: dependent on artificial environments for their continued existence (will not survive on own). Selective Breeding Selective breeding can also bring about bad or undesirable traits Some breeds of dogs are selectively bred for their aggressiveness, however, this sometimes produces dogs are too aggressive an cannot be controlled. Below is a picture of a horse (left) and donkey (right) and a mule (bottom). When a horse is bred with a donkey a mule is produced. A mule has the strength of a horse and the sure footedness (balance) of a donkey. Undesirable traits • Stubborn • Sterile – cannot reproduce Make a T chart Natural Selection Selective Breeding Selective Breeding or Natural Leafy Sea Dragon CabbageSelection Varieties …you decide SELECTIVE NATURAL BREEDING SELECTION Selective Breeding or Natural Leafy Sea Dragon CabbageSelection Varieties …you decide Selective Breeding or Natural Selection …you decide Bengal Cat Tesonite (Corn) Selective Breeding or Natural Selection …you decide SELECTIVE SELECTIVE BREEDING BREEDING Bengal Cat Tesonite (Corn) SelectiveLiger Breeding or Natural Selection …you decide Puggle Selective Breeding or Natural Selection …you decide SELECTIVE SELECTIVE BREEDING BREEDING Liger Puggle EyesSelective that rotate in all directions Breeding or Natural Selection …you decide zebra EyesSelective that rotate in all directions Breeding or Natural Selection …you decide NATURAL NATURAL SELECTION SELECTION zebra .