THE THEORY OF EVOLUTION Name: Period: Date: I. Evolution- A brief overview EVOLUTION IS: 1. 2. Descent with modifications 3. Plants and animals of today are forms of plants and animals of the past 4. Organisms vary and new forms appear, while old forms decline or become extinct ** Evolution is theologically neutral- it interprets a natural process - it describes -- not why - it is based on recognition of order not purpose EVOLUTION is NOT: 1. Man came from monkey EVIDENCE FOR EVOLUTION Genetic Comparison Fossils Anatomical studies Functionless structures Embryological development II. 2 Theories of Evolution: 1. Observed a relationship between the organism and its environment Recognized change in living things over long periods of time But he was INCORRECT in concluding that the environment acted directly on organisms to produce hereditary change in relation to need, use or disuse, or passing on of. 1
2. Charles Darwin: A. Voyage In 1831 was recommended as a naturalist on, a ship chartered for a five-year collecting and mapping expedition to South America and the South Pacific. Job: collect, study, and store specimens Developed a hypothesis based on observations, specifically in o Studied and compared the anatomy of many species of reptiles, insects, birds, and flowering plants o Noticed that these species were unique to the islands, yet similar to species seen in other parts of the world Darwin s Finches: o Darwin s observations - all the finches on the Galapagos island looked about the same except for the of their beak. o Conclusion - all the finches were descendents of the original population. o The shape of the beaks were for eating a particular type of food (Ex. long beaks were used for eating insects, short for seeds) = change in the gene pool of a population in response to various stimuli exhibited by a species OVER TIME. 2
B. What is Darwin s Explanation for Evolution? = a mechanism for change in populations that occurs when organisms with favorable variations for a particular environment survive, reproduce, and pass these variations on to the next generations. Wrote 3
Ex: Darwin s Idea of NATURAL SELECTION: 4
III. Natural Selection: = any trait that aids the chances of survival and reproduction of an organism. Two types: and o STRUCTURAL ADAPTATIONS arise over : = provides protection for an organism by enabling it to copy the appearance of another species. Coral snake-venom Scarlet king snake- non-venomous = enables an organism to blend in with its surroundings more likely to escape predators and survive to reproduce Example of Natural Selection: Lighter colored pepper moths less noticeable on lichen covered trees Pollution kills lichens and uncovers darker tree trunks o PHYSIOLOGICAL ADAPTATIONS can Changes in an organism Ex: Penicillin- was considered 50 years ago as a wonder drug b/c it could kill many types of disease-causing bacteria Now penicillin is not as effective as it used to be because many species of bacteria have evolved physiological adaptations that make them resistant to penicillin Ex: insects/ weeds have been selected for physiological resistance to chemicals used in pesticides. 5
VI. Evidence for Evolution: 1. : nucleotide sequencing studies are used to indicate levels of relationships among species within major taxonomic groups 2. : fossil records show how organisms have changed over time (millions of years) 3. : = Similarities in structure and arrangement likeness indicates a genetic relationship through a common ancestor. Ex: Homology among the bones of the forelimb. : Although these structures show considerable differences in form and function, the same basic bones are present in the forelimbs of humans, cats, bats, porpoises, and horses. 4. : = any body structure that is reduced in function in a living organism but may have been used in an ancestor. Examples: pelvis in snakes external ears and pelvis in whales Humans: appendix, ear muscles, nictitating membrane, wisdom teeth. 6
5. : Development of the phylum- in the embryonic stage it is difficult to distinguish fish, amphibians, reptiles, birds, and mammals. VII. Microevolution = evolutionary change below the level of species, and refers to changes in the frequency within a population or a species of its alleles (alternative genes) and their effects on the form, or phenotype, of organisms that make up that population or species. 1) Relatively short period of time 2) = members of single species living & reproducing in a specific area 7
VIII. Causes Of Microevolution: = change in allele frequencies in a gene pool due to chance. Increase/decrease based on which members survive & reproduce. Greater impact in population Types: bottleneck effect, founder effect 1) = process in which a large population declines in number, then rebounds. Catastrophic event leaves few survivors, limiting the gene pool for the next generation. Caused by natural disaster, habitat loss, overharvesting 2) = random effect that can occur when a small population settles in an area separated from the rest of the population and interbreeds, producing unique allelic variations. Rare alleles occur at a higher frequency in isolated populations. Initial founders of the population received their alleles by chance. Due to small population, rare gene continually passed on. IX. Macroevolution = any evolutionary change at or above the level of species. Requires = splitting of 1 species into 2 or more = do not have to look the same but can successfully interbreed Prevents from entering a population s gene pool through geographic, ecological, behavioral, or other differences 8
X. Causes of Macroevolution: 1) Species separated by major physical boundaries Ex: Oceans, rivers, mountains 2) Live in close proximity, but rarely interact due to different habitats Ex: Jungle canopy dwellers vs. those living on forest floor. 3) Live together but reproduce at different times of the year. 4) Courtship patterns are used to recognize mates. Chemical, vocal or physical indicators Ex: meadowlarks- have overlapping ranges & similar in appearance, but their songs separate them behaviorally 9
5) Floral structures or animal genitalia are incompatible making reproduction impossible. 6) Gametes from incompatible species will not fuse together to form a zygote. Fertilization has occurred but a hybrid offspring cannot develop or reproduce. - Ex: Liger 10
THEORY OF EVOLUTION WORKSHEET Name: Period: Date: Answer the following questions using your notes. 1. Define evolution in your own words. 2. State one misconception about evolution. 3. List 5 evidences of evolution. A. B. C. D. E. 4. Explain the misconception in Lamark s theory of evolution. 5. Where did Darwin complete his research and what principle does he use to back up his theory? 6. Define natural selection. 11
7. "Survival of the fittest" is a common expression. What do you think most people mean by this expression? How would you explain this expression to help someone understand how natural selection actually functions? 8. List the two types of adaptations and give an example of each. 9. = any trait that aids the chances of survival and reproduction of an organism. 10. What is the difference between a vestigial structure and homologous structure? 11. Look at the diagram below. Describe what is happening to the mice in figures 1-3 and give a possible explanation. 12
12. Explain the difference between macroevolution and microevolution. 13. Which type of evolution requires speciation? 14. Which type of evolution would most likely occur over a shorter period of time? 15. is a change in allele frequencies in a gene pool due to chance. 16. What are two examples of genetic drift? a. b. 17. Which type of genetic drift is caused by catastrophic events like a natural disaster, habitat loss or overharvesting? 18. is the process in which a large population declines in number, then rebounds. 19. is the random effect that can occur when a small population settles in an area separated from the rest of the population and interbreeds, producing unique allelic variations. 20. List and describe 3 causes of macroevolution.. 13
Unit Learning Map (5 days): Evolution Mrs.Sim Class:Biology B: Explain the mechanism of the theory of evolution. Analyze data from fossil records, similarities in anatomy and physiology, embryological studies and DNA studies that are relevant to the theory of evolution. Unit Essential Question(s): How does natural selection drive changes in the ecosystem? Optional Instructional Tools: Goldfish lab Darwin s Pond Antibiotic Resistance Flyer Concept Concept Concept Concept Natural selection Macroevolution vs. Microevolution Lesson Essential Questions: Lesson Essential Questions: Lesson Essential Questions: Lesson Essential Questions: How can the environment impact natural selection? Explain the differences between macroevolution and microevolution. Vocabulary: Vocabulary: Vocabulary: Vocabulary: Natural selection Lamark Acquired traits Darwin Evolution Adaptations Structural adaptations Physical adaptations Homologous structures Vestigial structures Microevolution Genetic drift Founder effect Bottleneck effect Macroevolution Speciation Geographic Isolation Habitat Isolation Temporal Isolation Behavioral Isolation Mechanical Isolation Gamete Isolation 14
Evolution Vocabulary: 1) Natural Selection = a mechanism for change in populations that occurs when organisms with favorable variations for a particular environment survive, reproduce, and pass these variations on to the next generations 2) Lamark (1801) = Observed a relationship between the organism and its environment Recognized change in living things over long periods of time But he was INCORRECT in concluding that the environment acted directly on organisms to produce hereditary change in relation to need, use or disuse, or passing on of acquired traits 3) Acquired traits = the environment acted directly on organisms to produce hereditary change in relation to need, use or disuse, or passing on of traits. 4) Charles Darwin = credited for the accepted theory of evolution (natural selection) In 1831 was recommended as a naturalist on HMS Beagle, a ship chartered for a five year collecting and mapping expedition to South America and the South Pacific. Developed a hypothesis based on observations, specifically in The Galapagos Islands 5) Evolution = change in the gene pool of a population in response to various stimuli exhibited by a species OVER TIME 6) Natural Selection = (Darwin s explanation of evolution) a mechanism for change in populations that occurs when organisms with favorable variations for a particular environment survive, reproduce, and pass these variations on to the next generations. 7) Adaptation = any trait that aids the chances of survival and reproduction of an organism 8) Structural adaptations = may arise over many generations (mimicry and camouflage) 9) Physical adaptations = may develop quickly (antibiotic resistance) 10) Homologous Structures = Similarities in structure and arrangement likeness indicates a genetic relationship through a common ancestor 11) Vestigial structure = any body structure that is reduced in function in a living organism but may have been used in an ancestor 12) Microevolution = evolutionary change below the level of species, and refers to changes in the frequency within a population or a species of its alleles (alternative genes) and their effects on the form, or phenotype, of organisms that make up that population or species. 13) Genetic Drift = change in allele frequencies in a gene pool due to chance. 14) Bottleneck Effect = process in which a large population declines in number, then rebounds. 15) Founder Effect = random effect that can occur when a small population settles in an area separated from the rest of the population and interbreeds, producing unique allelic variations. 16) Macroevolution = any evolutionary change at or above the level of species. 17) Speciation = splitting of 1 species into 2 or more 15
18) Geographic Isolation = species separated by major physical boundaries 19) Habitat Isolation = live in close proximity, but rarely interact due to different habitats 20) Temporal Isolation = live together but reproduce at different times of the year. 21) Behavioral Isolation = courtship patterns are used to recognize mates. 22) Mechanical Isolation = floral structures or animal genitalia are incompatible making reproduction impossible. 23) Gamete Isolation = gametes from incompatible species will not fuse together to form a zygote and/or a hybrid offspring cannot develop or reproduce 16