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How Genetic Variation and the Environment influence Natural Selection

How Genetic Variation and the Environment influence Natural Selection. Summary of Darwin’s Theory. 1. Organisms differ; variation is inherited 2. Organisms produce more offspring than survive 3. Organisms compete for resources

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How Genetic Variation and the Environment influence Natural Selection

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  1. How Genetic Variation and the Environment influence Natural Selection

  2. Summary of Darwin’s Theory 1. Organisms differ; variation is inherited 2. Organisms produce more offspring than survive 3. Organisms compete for resources 4. Organisms with advantages survive to pass those advantages to their children 5. Species alive today are descended with modifications from common ancestors

  3. Natural Selection The traits that help an organism survive in a particular environment are “selected” by the conditions of the environment

  4. Natural Selection The environment determines which traits are favorable for survival.

  5. It follows Logically that … • Some individuals will be better suited to their environment - they will survive and reproduce more successfully than individuals without those characteristics. • Future generations will thus contain more genes from better-suited individuals. • As a result, characteristics will evolve over time to resemble those of the better-suited ancestors.

  6. Regents Review Question # 1 Ancestors of the giant panda had rounded paws with five very short toes. Today, the giant panda has a sixth toe, often referred to as a thumb, even though it develops from a wrist bone. This unique thumb is an adaptation that allows the panda to easily hold and eat bamboo shoots. The presence of the giant panda’s thumb is most likely the result of (1) natural selection (2) selective breeding (3) asexual reproduction (4) ecological succession

  7. Regents Review Question # 1 (answer) Ancestors of the giant panda had rounded paws with five very short toes. Today, the giant panda has a sixth toe, often referred to as a thumb, even though it develops from a wrist bone. This unique thumb is an adaptation that allows the panda to easily hold and eat bamboo shoots. The presence of the giant panda’s thumb is most likely the result of (1) natural selection (2) selective breeding (3) asexual reproduction (4) ecological succession

  8. Regents Review Question # 2 A species that lacks the variation necessary to adapt to a changing environment is more likely to (1) develop many mutated cells (2) become extinct over time (3) begin to reproduce sexually (4) develop resistance to diseases

  9. Regents Review Question # 2 (Answer) A species that lacks the variation necessary to adapt to a changing environment is more likely to (1) develop many mutated cells (2) become extinct over time (3) begin to reproduce sexually (4) develop resistance to diseases

  10. Regents Review Question #3 Which statement is best supported by the theory of evolution? (1) Genetic alterations occur every time cell reproduction occurs. (2) The fossil record provides samples of every organism that ever lived. (3) Populations that have advantageous characteristics will increase in number. (4) Few organisms survive when the environment remains the same

  11. Regents Review Question #3 (Answer) • Which statement is best supported by the theory of evolution? • Genetic alterations occur every time cell reproduction occurs. • (2) The fossil record provides samples of every organism that ever lived. • (3) Populations that have advantageous characteristics will increase in number. • (4) Few organisms survive when the environment remains the same.

  12. Regents Review Question # 4

  13. Regents Review Question # 5

  14. Natural Selection explains the development of pesticide resistance in insects

  15. Natural Selection is also responsible for: Antibiotic resistance in bacteria

  16. MRSA methicillin-resistant Staphylococcus aureus bacteria

  17. Necrotizing Fasciitis Streptococcus pyogenes aka “Flesh Eating Bacteria”

  18. Classification Classification the grouping of information or objects based on similarities.

  19. Naming Organisms • We only know about a fraction of the organisms that exist or have existed on Earth. • A unique scientific name is given to • each species whether it’s alive today or extinct. • The scientific name comes from one of two • “dead” languages – Latin or ancient Greek.

  20. Binomial Nomenclature • a two name system for writing scientific names. • The genus name is written first (always Capitalized). • The species name is written second (never capitalized) • Feliscatus Felis catus

  21. Equus burchelli

  22. A key is a device for easily and quickly identifying an unknown organism. • The dichotomous key is the most widely used type in biological sciences. • The user is presented with a sequence of choices between two statements,couplets, based on characteristics of the organism. By always making the correct choice, the name of the organism will be revealed. The Dichotomous Key

  23. Here's an example in written form using these items: 1. a. Organism is living........................................................go to 4. 1. b. Organism is nonliving..................................................go to 2. 2. a. Object is metallic........................................................go to 3. 2. b. Object is nonmetallic..................................................ROCK 3. a. Object has wheels......................................................BICYCLE. 3. b. Object does not have wheels......................................TIN CAN.

  24. Regents Review Question #

  25. ANSWER: Sphyrna mokarran

  26. A phylogenetic tree or evolutionary tree is a branching diagram or "tree" showing the evolutionary relationships among various biological species based upon similarities and differences in their physical and/or genetic characteristics. It also is called a cladogram.

  27. Phylogenetic Tree

  28. Regents Review Question # 6 Which statement concerning the evolution of species A, B, C, D, and E is supported by the diagram below? (1) Species B and C can be found in today’s environments. (2) Species A and D evolved from E. (3) Species A and C can still interbreed. (4) Species A, B, and E all evolved from a common ancestor and all are successful today.

  29. Regents Review Question # 6 Which statement concerning the evolution of species A, B, C, D, and E is supported by the diagram below? (1) Species B and C can be found in today’s environments. (2) Species A and D evolved from E. (3) Species A and C can still interbreed. (4) Species A, B, and E all evolved from a common ancestor and all are successful today.

  30. Regents Review Question # 7 An evolutionary pathway is represented below. Which statement about evolutionary pathways is most accurate? (1) All evolutionary pathways show that life began with autotrophic organisms that soon evolved into heterotrophic organisms. (2) Two organisms on the same branch of an evolutionary pathway are more closely related to each other than to those on distant branches. (3) All the organisms shown at the ends of evolutionary pathway branch tips are alive today. (4) Evolutionary pathways show that evolution is a short-term process.

  31. Regents Review Question # (Answer) An evolutionary pathway is represented below. Which statement about evolutionary pathways is most accurate? (1) All evolutionary pathways show that life began with autotrophic organisms that soon evolved into heterotrophic organisms. (2) Two organisms on the same branch of an evolutionary pathway are more closely related to each other than to those on distant branches. (3) All the organisms shown at the ends of evolutionary pathway branch tips are alive today. (4) Evolutionary pathways show that evolution is a short-term process.

  32. Regents Review Question # 8 An inference that can be made from information in the diagram is that (1) many of the descendants of organism B became extinct (2) organism B was probably much larger than any of the other organisms represented (3) most of the descendants of organism B successfully adapted to their environmentand have survived to the present time (4) the letters above organism B represent members of a single large population with much biodiversity

  33. Regents Review Question # 8 An inference that can be made from information in the diagram is that (1) many of the descendants of organism B became extinct (2) organism B was probably much larger than any of the other organisms represented (3) most of the descendants of organism B successfully adapted to their environmentand have survived to the present time (4) the letters above organism B represent members of a single large population with much biodiversity

  34. THEEND

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