Game of Sperms

Raising a child is no easy task—what would you do if you were put in charge of raising someone else’s child? In a recent study, researchers from the Yale Department of Ecology and Evolutionary Biology explored whether males of different animal species would care for offspring that aren’t their own. The researchers studied how the energy needed to raise a child could affect males’ decisions to care for offspring.

Previous theories state that males are most likely to care for children that are certain to be their own. Yet in many species, a male may take care of offspring that were not conceived by him, but rather by a competing male. Postdoctoral Research Fellow Gustavo Requena explained the difference between his model and those of earlier theories. Requena said, “In our study, we used mathematical models to emulate males’ decisions in different scenarios and ultimately address the same question, but taking into account a more general biological reality.” This model involves sperm competition games, which show how males allocate energetic resources to increase their chances for success within male-male mating competition.

Factors that affect the males’ decisions include female promiscuity, maternal effort, and the difficulty of providing care to offspring. Based on these factors, researchers found that when there is more energy required, males will provide care based on relatedness to his offspring. However, in low cost situations, males will provide care regardless of relation.

In this way, scientists hope to provide an answer as to why males continue to provide energetically-costly care towards offspring that may not be their own. From these results, they can develop a greater understanding of different parenting patterns in nature.