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:11/29/2016)... , Nov. 29, 2016   ... identification and object recognition technologies, today released ... for fingerprint recognition solutions that run on ... fingerprint template using less than 128KB of ... compact devices that have limited on-board resources, ...
(Date:11/28/2016)... 2016 "The biometric system ... The biometric system market is in the growth ... near future. The biometric system market is expected to ... a CAGR of 16.79% between 2016 and 2022. Government ... technology in smartphones, rising use of biometric technology in ...
(Date:11/22/2016)... 2016 According to the new market research report ... Vein, Signature, Voice), Multi-Factor), Component (Hardware and Software), Function (Contact and Non-contact), ... market is expected to grow from USD 10.74 Billion in 2015 to ... 2016 and 2022. Continue Reading ... ...
Breaking Biology News(10 mins):
(Date:12/8/2016)... Dec. 8, 2016  Anaconda BioMed S.L., a pre-clinical ... the next generation neuro-thrombectomy system for the treatment of ... G. Jovin, MD to join its Scientific Advisory Board ... strategic network of scientific and clinical experts to Anaconda ... the ANCD BRAIN ® to its clinical phase. ...
(Date:12/8/2016)... ... December 08, 2016 , ... ... their exceptionally efficient human mesenchymal stem/stromal cell (hMSC) expansion medium. This ... products engineered to radically streamline culture processes, minimize processing time, significantly decrease ...
(Date:12/8/2016)... Ames, Iowa (PRWEB) , ... December 08, 2016 , ... ... of asynchronous approvals for biotech crops. The authors focus on the economic effects in ... the global approval of new biotech crops and the resultant risk of low level ...
(Date:12/8/2016)... -- Soligenix, Inc. (OTCQB: SNGX) (Soligenix or the Company), ... products to treat rare diseases where there is an ... hosting an Investor Webcast Event Friday, December 16, 2016, ... defense regulators (IDRs) as a new drug class, as ... recently announced and published Phase 2 clinical data for ...
Breaking Biology Technology: