4/10 Daily Catalyst Pg. 45 Evolution of Bacteria 1. List the three condition of Hardy-Weinberg Equilibrium that can NEVER be met. 2. Describe the second HWE condition of “no gene flow”. 3. What information can we derive from transitional forms?

Eduardo Stephanie

4/10 Class Business Pg. 45 Evolution of Bacteria Quiz #11 TODAY Evidence for Darwin’s Theory Evolution test on Thursday, April 16th Study guide due test day Review day on Wednesday, April 15th Quiz #12 on Review day Human body begins on Friday, April 17th

4/10 Agenda Pg. 45 Evolution of Bacteria Daily catalyst Class Business Dichotomous Keys Evolution of Bacteria Video clip Work time

Work time Directions: As a group, complete the 3 dichotomous key at each station. You have 7 minutes to complete each key. When you have finished the keys, return to your desk. The keys will be completed the answer sheet. Time: 21 minutes Noise: 1 (with groups)

1 2 3 4 5 6 7 8 Stephanie Eva Kayla Travis Fabien Amani Stephen Smokey Francisco Zaven Chris E. Chase Ridel Avery Eliud Nicoh Terriyan Andrea Nick Jonathan Hefer Daniel G. David Eric Darrius Eduardo Mickey Daniel V. Barrian Brian

Populations of organisms continue to evolve 4/10 Daily Objective We will be able to evaluate given data sets that illustrate evolution as an ongoing process. Essential knowledge: Populations of organisms continue to evolve

Prior Knowledge What do we know about bacteria?

Key Point #1 Prokaryotic Eukaryotic LIFE

Key Point #1 Prokaryotic Eukaryotic LIFE Plants and Animals Bacteria

Characteristics of Bacteria Key Point #2: Characteristics of Bacteria- Prokaryotic cell Single celled Contains circular DNA Can replicate and grow on its own

Characteristics of Bacteria Key Point #3: Since Bacteria have DNA, they can evolve too. We have seen bacteria change over time (evolve) due to a changing environment. The bacteria need to adapt to this changing environment. How does bacterial evolution affect us???

Resisting our drugs Antibiotics, such as penicillin, are drugs that kill or prevent the growth of bacteria. When antibiotics were first discovered, they seemed to represent a miracle cure for human diseases like pneumonia, typhoid, bubonic plague, and gonorrhea. However, almost immediately after the introduction of antibiotics, bacteria began to change — resistant strains of bacteria soon evolved that could grow even in the presence of a particular antibiotic, rendering our drugs ineffective in battling these resistant infections.

The problem is much like running on a treadmill — medical researchers must sweat just to stay in the same place in their race against the bacteria. Drug companies develop and introduce a new antibiotic, only to see the evolution of resistant bacterial strains within a few years. This necessitates the development of yet another antibiotic, which, in turn, becomes useless in the face of newly evolved resistant bacteria.

How exactly does antibiotic resistance evolve How exactly does antibiotic resistance evolve? How have such small and simple organisms managed to repeatedly outpace our drugs? The process is quite simply evolution by natural selection — but bacteria have a few secret weapons that give them an edge. Imagine a population of bacteria infecting a patient in a hospital. The patient is treated with an antibiotic. The drug kills most of the bacteria but there are a few individual bacteria that happen to carry a gene that allows them to survive the onslaught of antibiotic. These survivors reproduce, passing on the gene for resistance to their offspring, and soon the patient is populated by an antibiotic resistant infection — one that not only affects the original patient but that can also be passed on to other patients in the hospital. Key Point #4: Why do bacteria become resistant?

What can we do? A strategy being considered for use in hospitals called cycling. The idea is simple: doctors in a hospital would cycle through antibiotics, prescribing a particular antibiotic for period of time and then switching to a new one. Researchers and clinicians thought that cycling would reduce levels of antibiotic resistance because the bacteria would not have time to evolve to keep up with the changing drugs — just as a resistant strain for Drug #1 evolves and spreads, along comes Drug #2, and strains resistant to Drug #1 no longer have any advantage. Key Point #4: What is a solution to antibiotic resistance? Cycling different antibiotics

What is your opinion?

Worksheet: PBS video clip http://www.pbs.org/wgbh/evolution/educators/lessons/lesson6/act1.html

Work time Directions: Complete the book work on bacteria resistance. Your ws is due at the end of CLASS! Noise: 1 (with partner) Time: 10:40

Quiz #11 Directions: Silently and independently complete quiz #11. Turn the quiz into the basket when you are finished. Time: 13 minutes Noise: 0 (SILENT)