I had never stopped to wonder whether the number of spouses a male or female has affects the number of children each has. I found an interesting publication in the journal Behavioral Ecology called “Serial Monogamy Increases Reproductive Success in Men but not in Women” by Markus Jokela. He and his team of researchers predicted that males seek more sexual partners than females because of their higher fitness benefits from having this be their reproductive strategy.
Because of this, they hypothesized that the variance in numbers of partners and offspring is expected to be greater and association between mating and reproductive success to be stronger in males. To do this, they used the data of 3700 men and 4010 women living across the United States and noted the sex differences in the variance of number of spouses and offspring and in the association between spouse number and number of offspring.
As you may have assumed, the results showed that there was a stronger selective advantage of serial monogamy in men than in women. This means that variance in spouse and offspring number was, respectively, 5% and 10% higher in men. In addition, the data recorded displayed that the association between mating and reproductive success was stronger in men than woman. This could be seen because men with 3 or more consecutive spouses had 19% more children than men with only spouse. At the same time, women did not show any relationship between the number of children and number of spouses after the first spouse.
Interestingly, the sex differences were even stronger among Black and Hispanic participants than among White participants. I wonder if there is data showing further differences, possibly neighborhood and income levels, and whether the sex differences are even farther then those already observed in the data, specifically regarding males. Learning about these trends shows us that reproductive success can be measured in humans as well as other species through analysis of different types of data (in this case demographics), and that humans are similar to other species in mate selection after all.
Ahmed Sandakli (3)
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Wow, it’s odd to learn about reproductive success in our own society! I also remember reading that monogamy is advantageous for males depending on their social status. High-ranked males benefit from polygamy because they are able to attract many females and thus increase their reproductive success. However, low-ranking males benefit from monogamy because they are more likely to secure a mate if everyone is paired off. In other words, one male is only allowed one female, which limits the number of females capable of mating with high-ranking males. As you mentioned, it would be interesting to see if this translates to income levels.
ReplyDeletePosted by Katie Kalutkiewicz
This is a really interesting study if you think about it, because there are so many factors that could influence the outcome. Like, for example, I know that (at least for animals) monogamy is more advantageous for females because having two mates providing parental care greatly increases the offspring's chances of survival. In human polygamous relationships, with one husband and many wives, having many "partners" all caring for the offspring together almost seems like it would work out great for everyone. I don't think that's the kind of polygamy that was studied in this situation, but it almost makes you wonder why more people don't do it (besides that it's illegal and culturally weird in this country).
ReplyDelete-Jane de Verges
Its odd to think about reproductive success in humans like we do in animals. In animals it always seems like their one goal is getting as many copies of their genes into the population. Human culture has made reproduction more about love, but their are still underlying biological aspects of our brain telling us to do the same thing as animals.
ReplyDeleteCharles Carville
All very good points. Our higher learning and brain capacities have obviously evolved the our human population to think in terms of feelings and emotions as oppose to simply methodically seeking to make copies of our DNA. As mentioned in both my post and in a comment, it would be very interesting to evaluate human relationships and break them down into further categories, and see how a males' and females' reproductive success varies. very interesting article and i am glad it has sparked the curiosity of myself and others in the class regarding this topic. Applying laws and theories of nature to human beings is interesting because it often puts everyday things (in this case marriage and divorce)in a different and unique light.
ReplyDeleteAhmed Sandakli
I really like the way you presented this information. It turns humans right back into animals in my mind. It's very strange to think about humans in a biological way as animals as supposed to thinking about birth rates and how they affect our population socially. This really got me thinking about how no matter how many social laws or normalcies we create we will always have biological instinct.
ReplyDeletePosted by: Bailey Mannix