<p>The equation for evolutionary stability (13) defines positive and negative semi-planes, corresponding to favorable and non-favorable mutations, dependent on payoffs <i>b</i> and <i>c</i>. A population with arbitrary and (I) will always dispose of a positive region, precluding so an evolutionary stable solution. A sexual population (II) is evolutionary stable since no positive direction is available. The population on the (III) and (IV) edges are also unstable. If we assume opposite signs for the semi-planes as consequence of different payoff values, the asexual populations (positioned on the edges or ) become stable, while the sexual population becomes unstable.</p
