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 Change in genetic traits over time because of environmental factors Selective Breeding The mating of parent organisms by humans to produce desired traits in the next 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 Cabbage Varieties Leafy Sea Dragon Selection you decide
SELECTIVE NATURAL BREEDING Selective Breeding or Natural Cabbage Varieties SELECTION Leafy Sea Dragon Selection you decide
Selective Breeding or Natural Selection you decide Bengal Cat Tesonite (Corn)
Selective Breeding or Natural Selection you decide SELECTIVE BREEDING SELECTIVE BREEDING Bengal Cat Tesonite (Corn)
Selective Breeding or Natural Liger Selection you decide Puggle
Selective Breeding or Natural Selection you decide SELECTIVE BREEDING Liger SELECTIVE BREEDING Puggle
Selective Breeding or Natural Eyes that rotate in all directions Selection you decide zebra
Selective Breeding or Natural Eyes that rotate in all directions Selection you decide NATURAL SELECTION NATURAL SELECTION zebra