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Eat and Speciate. Kate Aubrecht, Melissa Fierke, Jeffrey Levinton, Greg McGee, Peg Riley Jen Nauen & Christov Roberson Northeast Summer Institute 2013. Evolution Unit: Intro Biology Learning Goals. Know what a species is Know how species evolve
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Eat and Speciate Kate Aubrecht, Melissa Fierke, Jeffrey Levinton, Greg McGee, Peg Riley Jen Nauen & Christov Roberson Northeast Summer Institute 2013
Evolution Unit: Intro BiologyLearning Goals • Know what a species is • Know how species evolve • Understand how speciation increases biodiversity
Activity Learning Outcomes • Students should be able to: • Describe processes leading to speciation • Interpret experimental data
Which of the following are different species? Red and blue individuals coexisting in the same population Two groups of individuals that look similar but can not produce fertile offspring when they mate A population of fish that is separated and placed into two different fish tanks Clicker Question 1Review
Clicker Question 2Review This schematic represents what type of speciation? Allopatric Sympatric Neither
Fruit flies reared on diets of starch or cornmeal/molasses/yeast (CMY) for 11 generations CMY Reared for 1 generation Mating arena From Shannon et al., 2010. PNAS
Group-think-share Data from: Shannon et al., 2010. PNAS 107 (46): 20051-20056
Add antibiotics to food… + antibiotics + antibiotics
Group-think-share Data reconstructed from: Shannon et al., 2010. PNAS 107 (46): 20051-20056
Clicker Question 3 Was there evidence of speciation during this experiment? • Yes • No
Group-think-share If this experiment was allowed to continue (without antibiotics), could speciation occur? If so, how? Genetic divergence due to reproductive isolation.
Let’s look at a real life example of speciation potentially aided by microbiome differences Species of parasitoid wasps Nasonia, closely related but with different microbiomes Brucker & Bordenstein 2013 Science
Cross closely related Nasonia vitripennis & N. longicornis • Different species have different microbiomes • Crosses lethal for >90% of males! • Administer antibiotics and they produce viable offspring • Different species have likely evolved differently in response to their species microbiome • Leads to increases in biodiversity
Muddiest Point • Don’t forget… by 6:00 today go onto the course website and post the least clear aspect of today’s exercise.