Why Fathering Another’s Offspring is Often Better for Cuckolded Males
Scientists may have discovered the reason why males in many species still provide paternal care, even when their offspring may not belong to them.
A new study published March 26 in the journal PLOS Biology reveals that when the conditions are right, sticking around despite being "cuckolded" may actually be the most successful evolutionary strategy.
Male in many species often care for offspring that are not their own. While caring for someone else's offspring makes little sense because natural selection should dictate that males only care for the offspring that carry their genes, the latest study suggests that males are more tolerant and more astute than previously assumed.
After conducting a meta-analysis of 62 studies across 48 different species including insect, fish, birds and mammals, researchers found that males adjust their care according to how likely it is that females are unfaithful, while also taking into account how caring will potentially reduce the number of offspring they can have in the future.
The study reveals that overall, promiscuous copulations by females reduced the investment of males by 12 percent.
While parental care is highly variable across all the species studied in the analysis, researchers at the Lund University and the University of Oxford were still able to find a general explanation for why sticking around to care for the offspring is the better choice for some cuckolded males. Researchers found that males were more accepting of offspring fathered by other males in species where the risk of cuckoldry is generally low, or when caring does not harm their future reproductive success.
"This, to me, shows the strength of natural selection, with its footprints clear in species from burying beetles-which care for young over a few weeks by regurgitating dead mice-to humans, who spend years providing for their children", researcher Charlie Cornwallis of Lund University said in a statement. "These are complex calculations that males are making, and it has been difficult to measure the relevant factors correctly, but looking across species has helped us work out what is going on. "
"Moreover, a comparative study like this can guide researchers to the types of species and experimental cues that are likely to provide the most insight into paternal care in the future," he added.
Researchers said the plan on designing studies to further test their findings. They want to understand why such tolerance has been favored by natural selection and to be able to predict what males will do in species that have not yet been studied.