When? optimal residence time optimal lysis time
t2t2 t1t1 b1b1 b2b2 The lysis time t is optimal when d ln(b) d t = ln(b) 1/(r N) + t Graphical Solution of the Optimal Lysis Time ln(phage/cell) 1/(rN) adsorption N: host concentration r: adsorption rate 0 eclipse maturation
Environments with different host quantities: N 1 > N 2 Evolution of Optimal Lysis Time ln(phage/cell) Wang et al. (1996) Evol. Ecol. 10: t2t2 t1t1 t 1 < t 2 N 1 > N 2 1/(rN 2 )1/(rN 1 )
Wang et al. (1996) Evol. Ecol. 10: t1t1 t2t2 t 1 < t 2 Q 1 > Q 2 1/(rN) Q1Q1 Q2Q2 Evolution of Optimal Lysis Time ln(phage/cell) Different Environments with different host qualities: Q 1 > Q 2
Summary (1)High host quantity (which reduces “travel” time) promotes shorter lysis time, and vice versa. (2) High host quality (between environments) promotes shorter lysis time, and vice versa. Both Life-History Predictions Invoke MVT
Parker, G.A Evolution 28:93. Male Copulatory Duration: Fertilization of Ova Has Diminishing Returns Dungflies: Copulate Near Cowpats, Oviposition Given Resource, Males Arrive First Females Arrive; Males Compete Mating; Male Guards Female During Oviposition Male Searches for New Mate
Cycle for Males Time Guarding Female, Search Time Gain Fertilizations During Mating Guarding + Search = Travel (Constraints) Male can Adjust Copulation Time
Guarding + Search = Minutes
Parker, G.A Evolution 28:93. Hypothesis: Selection can favor long-term rate at which a male fertilizes ova. MVT: Some Understanding of Mating Behavior