Table 1 Abbreviations and variables used in the model.
From: Self-sacrifice in 'desperado' contests between relatives
Variable | Range | Significance |
|---|---|---|
Q1 | na | The contestant holding the advantage in some form of asymmetry, which will thus win the contest if no overt fighting occurs. |
Q2 | na | The opponent, who will lose the contest unless it fights Q1. |
V | na | Fitness value of the contest (ie: lifetime fitness of the queen that inherits the colony). |
Vo | na | Fitness value of the future (ie: outside of the contest). Vo is here set to 0, as queens have no reproductive opportunities outside the contest. |
a | 0 to 1 | The probability of Q1 winning an overt fight, here expressed as a linear function of relative fighting ability: a = ½(f+1) |
d | 0 to 1 | The probability that fighting will result in the death of both queens, based on the mortality index and relative fighting ability, such that d =m for contestants of equal fighting ability, and declines with increasing disparity in fighting ability following d = m. e-αf² |
r | 0 to 1 | Genetic relatedness between contestants. |
f | -1 to 1 | Relative fighting ability of Q1. When f = -1, Q1 has a lower fighting ability than Q2; when f = 0, Q1 and Q2 have equal fighting abilities; and when f = +1, Q1 has a higher fighting ability. |
m | 0 to 1 | Mortality index. A factor based on the lethality of unrestrained combat for the species in question, expressed as a probability that a fight between contestants of equal fighting ability will lead to the death of both contestants. |
α | ≥0 | A factor defining the shape of the curve describing the effect of relative fighting ability on the chance of mortality of both queens (Fig. 3). |