Give an example of a trait that may have evolved as a result of the handicap principle and explain your reasoning.

The handicap principle may be defined as the evolution on the basis of the reliable or honest signalling between the animals. This principle was given by the scientist Amotz Zahavi.

The trait that follow the handicap principle is peacock tail. The attractive peacock tail lure the predators and reduces the chances of escape of the peacock. This may acts as disadvantage but only chose the fittest males among the population. The tails attract the females as the tail is honest and sign of quality. In return male has more chances of mating and shows high reproductive success.  

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.