Super Gonorrhea Gonorrhea has become a superbug This
Super Gonorrhea? ! • Gonorrhea has become a superbug. This means that it has become resistant to antibiotics. In terms of natural selection, how has this happened?
Antibiotic Resistance What’s the selective pressure driving this population to evolve?
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? A. Since the need existed to survive the penicillin effect, bacteria responded by developing immunities. B. A variation for immunity to penicillin already existed and became predominant in surviving bacteria. C. In response to so many being killed by antibiotics, bacteria began mutating into resistant strains. D. Other species of bacteria that penicillin does not affect mutated and now cause these infections.
Which of the following is not part of Darwin’s theory of evolution? A. B. C. D. Struggle for Existence Inheritance of Acquired Traits Descent with Modification Survival of the Fittest
Summary of Darwin’s Theory
1. Individual organisms of a population differ & much of this variation is heritable (in the genes). A few of these baby sea turtles have a gene that allows them to move quickly on land. The others are slow on land.
2. Organisms produce more offspring than can survive & those who do not survive do not reproduce. Only 1 in 1, 000 baby sea turtles will make it to adulthood.
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. Some baby sea turtles are more quick on land than the others. The fastest baby sea turtles will make it to the ocean quickly, avoiding predators. These turtles will survive & reproduce. The offspring will inherit the fast genes.
4. Species alive today are descended with modification from ancestral species that lived in the distant past (descent with modification). Archelon ischyros, an extinct ancestor of the green sea turtle, was one of the largest turtles that ever lived (10 -13 ft. )!
Evidence for Evolution • • • Embryology Body Structures The Fossil Record Biogeography Genetic Similarities (DNA)
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? A. B. C. D. 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
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
Birds and reptiles are similar in that they are vertebrates & lay eggs. They differ in that reptiles have teeth & 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.
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 & 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.
Which structures indicate common ancestry? A. B. C. D. Homologous Structures Analogous Structures Both Neither
When your friend says that something is “just a theory” what do they mean?
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!
A scientific theory is… • A well-tested explanation – – Based on a broad range of observations & data Accepted to be true by the scientific community Tested repeatedly Not absolute – can be tweaked, but seldom entirely replaced Darwin’s original hypothesis is now known as the Scientific Theory of Biological Evolution.
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. Darwin formed his hypothesis based on observations he made on his journey around the world.
In science, a well tested explanation that unifies a broad range of observations is a - A. B. C. D. Theory Hypothesis Inference Law
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