Human skin-color sexual dimorphism: A test of the sexual selection hypothesis. Reply to Frost (2007)

2007 ◽  
Vol 133 (1) ◽  
pp. 780-781 ◽  
Author(s):  
Lorena Madrigal ◽  
William Kelly
Keyword(s):  
Sexual Selection ◽  
Sexual Dimorphism ◽  
Human Skin ◽  
Skin Color ◽  
Selection Hypothesis ◽  
Sexual Selection Hypothesis

scholarly journals An infanticide attempt by a free-roaming feral stallion ( Equus caballus )

2008 ◽  
Vol 5 (1) ◽  
pp. 23-25 ◽  
Author(s):  
Meeghan E Gray
Keyword(s):  
Sexual Selection ◽  
Genetic Analysis ◽  
Equus Caballus ◽  
Adult Males ◽  
Free Living ◽  
Feral Horses ◽  
Selection Hypothesis ◽  
Sexual Selection Hypothesis ◽  
In Captivity

Infanticide by adult males occurs in a variety of species. While infanticidal attacks have been documented in several equid species in captivity, it has never been witnessed in free-roaming feral horses. I report an infanticide attempt by a free-living feral stallion on a recently born female foal. The stallion picked up the foal by the shoulders, tossed it around twice and bit in on the neck several times. The dam of the foal charged the stallion and successfully protected her foal from additional attacks. The foal survived the attack and later weaned successfully. The stallion recently took over the band and was excluded as the sire through genetic analysis. While this type of attack is rare, this case lends support to the sexual selection hypothesis and further demonstrates that equids have evolved with the risk of infanticide. Furthermore, it shows that maternal protectiveness can be successful against attacks by infanticidal males.

scholarly journals Sexual selection and the evolution of altruism: males are more altruistic and cooperative towards attractive females

2016 ◽  
Vol 7 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Manpal Singh Bhogal ◽  
Niall Galbraith ◽  
Ken Manktelow
Keyword(s):  
Game Theory ◽  
Sexual Selection ◽  
Kin Selection ◽  
Self Report ◽  
Economic Games ◽  
Selection Hypothesis ◽  
Contemporary Research ◽  
Sexual Selection Hypothesis ◽  
Game Theoretic

Explaining altruism through an evolutionary lens has been a challenge for evolutionary theorists. Where altruism towards kin is well understood through kin selection, altruism towards non-kin is an evolutionary puzzle. Contemporary research has found that, through a game-theoretic framework, sexual selection could be an explanation for the evolution of altruism. Research suggests that males are more altruistic towards females they are interested in engaging with, sexually or romantically when distributing stakes in economic games. This study, adopting a between-groups design, tested the sexual selection explanation for altruism by asking participants to self-report altruistic and cooperative intention when reading moral scenarios accompanied by attractive or unattractive images. We find that participants, particularly males, report being more altruistic and cooperative when viewing an attractive image of a female. This study replicates the sexual selection hypothesis in explaining altruism through an alternative experimental framework to game theory.

scholarly journals An observation of intergroup infanticide in grey-cheeked mangabeys (Lophocebus albigena)

Behaviour ◽  
2020 ◽  
Vol 157 (12-13) ◽  
pp. 1091-1098
Author(s):  
Michelle Brown
Keyword(s):  
Sexual Selection ◽  
National Park ◽  
Kibale National Park ◽  
Primate Species ◽  
Lophocebus Albigena ◽  
Selection Hypothesis ◽  
Sexual Selection Hypothesis ◽  
Intergroup Conflicts

Abstract In primates, infanticide is occasionally observed during intergroup conflicts but does not fit the predictions of the sexual selection hypothesis. I report an observation of an intergroup infanticide during a sub-group foray in grey-cheeked mangabeys (Lophocebus albigena) at the Ngogo site in Kibale National Park, Uganda. Intergroup infanticide appears to be a form of extreme and long-term food defence across primate species, and occurs in conjunction with other forms of food defence.

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