Contextdependent fitness in AvidaED Maren Friesen Andy Jarosz

Context-dependent fitness in Avida-ED Maren Friesen & Andy Jarosz 06 June 2015

Courses • • 162: Freshman second biology course & sophomores • 120 students 2 x 90 min lectures/wk Scientific reasoning & writing Quantitative skills (algebraic problem-solving) many students really struggle • • • 445: Juniors upper-level evolution & seniors • • 100 students 2 x 50 min lectures + 50 min recitation (25 students each) Tier 2 writing course Quantitative skills (algebraic problem-solving) many students (still) really struggle

Why do organisms "match" their environments?

What will happen when environments change? http: //www. npr. org/2013/09/08/220188619/climate-change-leaves-hares-wearing-the-wrongcolors

Learning Goals • Concept: Fitness is context-dependent • Objectives: • Make predictions about how organisms that have evolved in one environment will perform in another environment • Explain how some mutations can be adaptive under all environments while others can only be adaptive under some environments

Avida-ED • 3 types of environments • 1000 cycles with no rewards • 1000 cycles with only "nan" • 1000 cycles with only "not" • Save 3 Avidian genotypes per selection regime (2% mutation rate) • Measure fitness under all environments, plus "nan & not" [novel environment]

Predict which genotype(s) will be most fit in each environment Environment fitness is measured in No reward Not Nor Not & Nor Most fit genotype

Measuring Fitness start with ancestor and 9 evolved genotypes turn mutation off, update for 50 cycles Ancestor no reward nanose notose

Measuring Fitness start with ancestor and 9 evolved genotypes turn mutation off, update for 50 cycles Ancestor no reward nanose notose

Measuring Fitness start with ancestor and 9 evolved genotypes turn mutation off, update for 50 cycles Ancestor no reward nanose notose

Fitness Worksheet Environment fitness is measured in Environment they evolved in 0 (no reward) A 1 0 not nan not &nan Ancestor 2 3 NOT 1 2 NAN 3 1 2 3

no reward not & nan not ancestor no reward nanose norose nan

• • • Questions What happened to make all the evolved genotypes have higher fitness than the ancestor in the noreward environment? Explain why the fitness values are different in the "not" environment compared to the "nan" environment. What do you predict will happen if a "not"-adapted avidian is competed against a "nan"-adapted avidian in a not environment? What about if they compete in a nan environment? What about if both not & nan are available?

no reward not & nan not ancestor no reward nanose norose nan

Environment fitness is measured in Fitness Worksheet (M) Environment they evolved in 0 (no reward) A 0 1 2 3 NOT 1 2 NAN 3 1 2 3 0. 25 0. 28 0. 36 0. 44 0. 26 0. 3 not 0. 25 0. 28 0. 36 0. 44 0. 53 0. 59 0. 53 0. 26 0. 3 nan 0. 25 0. 28 0. 36 0. 44 0. 26 0. 3 0. 26 0. 61 0. 52 0. 59 not &nan 0. 25 0. 28 0. 36 0. 44 0. 53 0. 59 0. 53 0. 61 0. 52 0. 59 Ancestor

Fitness Worksheet (A) Environment they evolved in Environment fitness is measured in 2000 cycles @ 0. 5% 0 (no reward) A 0 1 2 3 NOT 1 2 NAN 3 1 2 3 0. 25 0. 32 0. 38 0. 37 0. 38 0. 48 not 0. 25 0. 32 0. 75 0. 74 0. 75 0. 48 nan 0. 25 0. 32 0. 38 0. 37 0. 38 0. 95 not &nan 0. 25 0. 32 0. 75 0. 74 0. 75 0. 95 Ancestor Discuss!

• • • Assessment: Exam Q Case study: Antibiotic-resistant bacteria. Fitness is measured in the presence and absence of the antibiotic for two different strains Strain 1: 0. 52 with antibiotic; 0. 52 without Strain 2: 0. 64 with antibiotic; 0. 45 without a) Predict the evolutionary outcome of a population containing both genotypes of bacteria (1) in the presence of the antibiotic (2) in the absence of the antibiotic. b) Explain why strain 1 and strain 2 have different fitnesses. c) What do you hypothesize about the environment that