Call it sperm competition.
According to a study appearing in Current Directions in Psychological Science, sexual characteristics exhibited by human males indicate that men have evolved to deliver their sperm more effectively to females who have multiple partners to choose from.
"Although many people are familiar with the idea of animals competing for mates before sex occurs, through mating displays such as bright feathers or butting antlers, we are finding more evidence that there is also competition after mating occurs," says author Todd K. Shackelford. "An alternative way of thinking about it is that there is not only competition between males for mates, but competition between males for fertilization."
The research presented in the review covers physical adaptations, including penis shape and style of intercourse, as well as behavior in response to perceived infidelity that all serve to increase the success of fertilization. "The studies have shown that when partners are separated for periods of time, males are more likely to arouse easily, produce more sperm, and even rape their partners," says Shackelford. According to Shackelford and co-author Aaron T. Goetz, this does not mean that women are promiscuous by nature, but it is evidence that humans are not naturally a monogamous species.
Shackelford is quick to point out, however, that females are not passive partners in the sexual relationship. "Although this review focused on male adaptations, sexual conflict between males and females produces a co-evolutionary arms race between the sexes, in which an advantage gained by one sex selects for counter-adaptations in the other sex."
Source: Blackwell Publishing.
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- The Law has Failed, Not Forensic Science
- Energy-Space Photography Captures Light Behaving As A Wave And A Particle
- Sun's Impact On Climate Is Greater In Cool Periods
- The Real Meaning Of The Blue Black White Gold Dress
- Cats Use Sight Over Smell When Finding Food
- How Mr. Spock Changed Our Perception Of Science
- Francis Halzen On Cosmogenic Neutrinos
- "Seems to me, the primary subject to be defined by religion is that of the question of being. Ontology..."
- "That comment makes no sense. It's like if blue-eyed women were in charge and geared everything..."
- "Doug:I presume that the z=0 is to stipulate that we are within the plane of a thin disk. ..."
- "Leftists are a wacky species. It's simple, really. A white man is more likely to have the constellation..."
- "Hi T, Thanks for blogging on this. Are the pdf/ppt files of presentations available online? ..."
- University 'ethics boards' as a way to evade scientific controversy
- Human Activity May Be Supporting Growth of Harmful Algae in Lakes
- The more friends you drink with, the more you drink
- Why Are Girls More Likely to Die in Pediatric Intensive Care Units?
- Mobile phones have quietly become a global government ID device