Why is monogamy considered natural

For a year

Penguins are known for their extraordinary division of labor: dad and mom take turns hating the offspring fairly. As long as the breeding season continues, penguin parents depend on each other and are also loyal during this time. However, the monogamy only lasts for about a year: In the next season the emperor penguins mate again. In this case, scientists speak of a "serial monogamy". The penguins do not cheat, but they also do not, as long suspected, remain loyal to a partner throughout their lives. In this way, the animals can increase the probability that their genes will be passed on to subsequent generations. For example, if a female miscarries or a male proves unable to reproduce, there is a new chance of healthy offspring in the following year.

Smart move of evolution

The white-handed gibbons, on the other hand, were considered model monogamists until 2010 - as great apes they are genetically much more similar to us than a swan or a seahorse. Then, however, biologists discovered in Thailand's Khao Yai National Park that the females were cheating. What was initially ridiculed as an isolated case soon turned out to be an evolutionary move: in gibbon populations, the males live socially monogamous. The females are spatially separated from each other - so it is easy for the males to pay their neighbors an occasional visit without the wife noticing anything. However, the females also use the advantages of this “open relationship”: Usually, infanticide among monkeys is not uncommon, for example when a male feels betrayed or feels threatened in his territory. However, if the males can never be sure that the children might not be their own offspring, they spare them.

By the way: For a long time, monogamy was not common in human society either. Until western colonial rulers traveled the earth and proselytized, around 85 percent of all indigenous peoples lived in polygamous relationships.