Navigation Links
Evolutionary forces explain why women live longer than men

Despite research efforts to find modern factors that would explain the different life expectancies of men and women, the gap is actually ancient and universal, according to University of Michigan researchers.

"Women live longer in almost every country, and the sex difference in lifespan has been recognized since at least the mid-18th century," said Daniel J. Kruger, a research scientist in the U-M School of Public Health and the Institute for Social Research. "It isn't a recent trend; it originates from our deep evolutionary history."

This skewed mortality isn't even unique to our species; the men come up short in common chimps and many other species, Kruger added.

Kruger and co-author Randolph Nesse, a professor of psychology and psychiatry and director of the Evolution and Human Adaptation Program, argue that the difference in life expectancy stems from the biological imperative of attracting mates.

"This whole pattern is a result of sexual selection and the roles that males and females play in reproduction," Kruger said, "Females generally invest more in offspring than males and are more limited in offspring quantity, thus males typically compete with each other to attract and retain female partners."

For example, in common chimps, the greatest difference in mortality rates for males and females occurs at about 13 years of age, when the males are just entering the breeding scene and competing aggressively for social status and females.

From the tail of the peacock to the blinged-out SUV, males compete aggressively for female attention, and that costs them something. In nature, it means riskier physiology and behavior for the males, such as putting more resources into flashy plumage or engaging in physical sparring.

And even in modern life, where most dueling is a form of entertainment, male behavior and physiology is shortening their lifespans relative to women, Kruger said. In fact, modern lifestyles ar e actually exacerbating the gap between male and female life expectancies.

Male physiology, shaped by eons of sexual competition, is putting the guys at a disadvantage in longevity. Male immune systems are somewhat weaker, and their bodies are less able to process the fat they eat, Kruger said. And behavioral causes---smoking, overeating, reckless driving, violence---set men apart from most women. "Because mortality rates in general are going down, behavioral causes of death are ever more prevalent," Kruger said.

Looking at human mortality rates sliced by socioeconomic status shows that the gender gap is affected by social standing. Human males in lower socio-economic levels tend to have higher mortality rates than their higher-status peers. The impact of social standing is greater on male mortality than on female mortality, Kruger noted, partially because males who have a relatively lower status or lack a mate engage in a riskier pattern of behaviors in an attempt to get ahead, he said.


'"/>

Source:University of Michigan


Related biology news :

1. Evolutionary conservation of a mechanism of longevity from worms to mammals
2. Evolutionary biology research techniques predict cancer
3. Evolutionary shifts in olfactory sensitivities in fruit flies
4. Evolutionary scrap-heap challenge: Antifreeze fish make sense out of junk DNA
5. Salk and Stanford teams join forces to reveal two paths of neurodegeneration
6. New genetic analysis forces re-draw of insect family tree
7. Sleep enforces the temporal sequence in memory
8. Gene variations explain drug dose required to control seizures
9. Jumping gene helps explain immune systems abilities
10. Gene sequencing explains bioremediation bug
11. Variation in womens X chromosomes may explain differences among individuals, between sexes
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:3/27/2017)... , March 27, 2017  Catholic Health ... and Management Systems Society (HIMSS) Analytics for achieving ... Adoption Model sm . In addition, CHS previously ... U.S. hospitals using an electronic medical record (EMR). ... its high level of EMR usage in an ...
(Date:3/22/2017)... VILNIUS, Lithuania , March 21, 2017 /PRNewswire/ ... identification and object recognition technologies, today announced the ... development kit (SDK), which provides improved facial recognition ... safety cameras on a single computer. The new ... algorithms to improve accuracy, and it utilizes a ...
(Date:3/16/2017)... CeBIT 2017 - Against identity fraud with DERMALOG solutions "Made in ... ... Used combined in one project, multi-biometric solutions provide a crucial contribution against identity fraud. ... Used combined in one project, multi-biometric solutions ... ...
Breaking Biology News(10 mins):
(Date:5/23/2017)... Colorado (PRWEB) , ... May 23, 2017 , ... A ... as the most troublesome and difficult to control weed in 12 categories of broadleaf ... , Almost 200 weed scientists across the U.S. and Canada participated in the 2016 ...
(Date:5/23/2017)... ... May 22, 2017 , ... ... in San Diego, California, this August will feature high-level speakers on quantum ... vehicles. , SPIE Optics and Photonics, the largest multidisciplinary optical sciences meeting in ...
(Date:5/23/2017)... , ... May 23, 2017 , ... Bacterial biofilms, surface ... molecules, can cause diverse pathologies ranging from food poisoning and catheter infections to gum ... is in the tens of billions of dollars per year, there is currently a ...
(Date:5/22/2017)... ... May 22, 2017 , ... Baltimore biotech firm, PathSensors, announced ... community in developing and issuing recommendations to grow Maryland's biohealth industry and position ... 2023. , The recommendations are contained in a report from ...
Breaking Biology Technology: