Super Gonorrhea?! EW!

1. Super Gonorrhea?! EW! • Gonorrhea is our newest superbug. This means that it has become resistant to drugs. In terms of natural selection, how has this happened?

2. Antibiotic Resistance What’s the selective pressure driving this population to evolve?

3. When the use of penicillin began heavily during World War II, it saved thousands of soldiers’ lives. Today, treatment of many infections by penicillin that were successful in the past are no longer effective. Which is the best explanation for this change? • Since the need existed to survive the penicillin effect, bacteria responded by developing immunities. • A variation for immunity to penicillin already existed and became predominant in surviving bacteria. • In response to so many being killed by antibiotics, bacteria began mutating into resistant strains. • Other species of bacteria that penicillin does not affect mutated and now cause these infections.

4. Summary of Darwin’s Theory

5. Which of the following is not part of Darwin’s theory of evolution? • Struggle for Existence • Inheritance of Acquired Traits • Struggle for Existence • Survival of the Fittest

6. 1. Individual organisms of a population differ & much of this variation is heritable (in the genes).For example, this rabbit population contains rabbits with different fur colors.

7. 2. Organisms produce more offspring than can survive & those who do not survive do not reproduce.For example, only 1 in 1,000 baby sea turtles will make it to adulthood.

8. 3. Each unique organism has different advantages & disadvantages in the struggle for existence. Individuals best suited to their environment survive & reproduce most successfully. They pass on their adaptations to their offspring. For example, the fastest/more alert zebras will survive & reproduce, passing down the good genes.

9. 4. Species alive today are descended with modification from ancestral species that lived in the distant past (descent with modification). For example, greater apes & lesser apes share a single common ancestor.

10. Evidence for Evolution • Embryology • Body Structures • The Fossil Record • Biogeography • Genetic Similarities (DNA)

11. Now compare the DNA to a close ancestor: Living organism: Ancestor: On which nucleotide(s) do the sequences differ? What is this difference called?

12. You try it! • You have 9 nitrogen base sequences from a section of DNA similar to what you might find in a human. Look for the sequence labeled “living DNA”. • Find the closest ancestor to the living DNA and place it below the living DNA • Place the rest of the sequences in the correct order, from present (living) to oldest ancestor.

13. What did you use to make your decision? Were you correct in your order? Assume the rate of mutation is 1 mutation for every 10,000 years. How many years separate the “living DNA” from its oldest ancestor?

14. The table below shows chemicals found in certain bacteria. Each capital letter represents a different chemical. Which 2 bacteria are most closely related? • Bacteria 1 & 2 • Bacteria 2 & 3 • Bacteria 2 & 4 • Bacteria 3 & 4 Bacteria 2 & 4!

15. Genetic variation can aid in the survival of species when the environment changes. Which of the following is the best example of an organism with a genetic variation that could improve survival chances over time? • An ant that is resistant to pesticide • A wasp that is infected with parasites • A cactus that has no spines • A mouse that has learned to avoid mousetraps

16. The table shows an amino acid comparison of cytochrome c, a protein involved in cellular respiration. The two organisms in the table that are least genetically related are the — A. silkworm moth and the fruit fly B.silkworm moth and the screwworm fly C. fruit fly and the screwworm fly D. fruit fly and the hornworm moth

17. Birds and reptiles are similar in that they are vertebrates and lay eggs. They differ in that reptiles have teeth and birds have beaks. Some birds do possess teeth. However, these teeth are present only in the embryonic stage. Which conclusion is best supported by the presence of teeth in bird embryos? A.Birds and reptiles share a common ancestor. B. Modern reptiles are the ancestors of modern birds. C. Birds and reptiles eat similar types of food. D. Ancestors of reptiles had beaks similar to those of birds.

18. The diagram illustrates how some characteristics of the horse have changed over time. Along with the difference in size, what is another anatomical difference between the modern horse and its ancestors? A. The structure of the tooth has been adapted for eating meat. B. The size of the molars has decreased. C. The length of the forefoot has decreased. D. The number of toes has decreased.

19. Which structures indicate common ancestry? • Homologous Structures • Analogous Structures • Both • Neither

20. When your friend says that something is “just a theory” what do they mean?

21. What’s a theory? • In non-scientific terms, if something is said to be “just a theory,” it usually means that it is a guess, or is unproven. BUT • In science, the word theory means something completely different!

22. A scientific theory is… • A well-tested explanation • Based on a broad range of observations and data • Accepted to be true by the scientific community as a whole • Tested repeatedly by new data • Not absolute – can be tweaked, but seldom entirely replaced

23. A hypothesis is… • Formulated from observations & is tested scientifically to develop supporting evidence. • Until sufficient supporting evidence is found, a hypothesis may be disputed by science.

24. In science, a well tested explanation that unifies a broad range of observations is a - • Theory • Hypothesis • Inference • Law