Transcript Sexual Selection and Mortality Rates

Sexual Selection and
Mortality Rates
Yvette Aranas & Mercedes Pineda
Dr. Mills
Psych 452
Kruger, D.J. & Nesse, R. M. (2004). Sexual selection and the Male: Female Mortality Ratio. Evolutionary
Psychology. 2, 66 - 85.
Video:
Why Women Live Longer Than Men.
Kruger, D.J. & Nesse, R. M. (2004). Sexual selection and the Male: Female Mortality Ratio. Evolutionary
Psychology. 2, 66 - 85.
Introduction: The Study
 Looked at 20 different countries and across the
past 70 years, only in 5 of those countries.
 Results are trends, rates and contributions of
proximate causes of death.
 Through differences with sexual selection
interaction, along with aspects of culture and
environment leads to consistency.
 Mortality ratio increases as general mortality rates
decrease.
Kruger, D.J. & Nesse, R. M. (2004). Sexual selection and the Male: Female Mortality Ratio. Evolutionary
Psychology. 2, 66 - 85.
Main critical points
 Females live longer:
 Males tend to have competition amongst
themselves for chances at sexual reproduction.
 Males are willing to risk more & invest less
time in the repair capacity.
 The survival of offspring depends on maternal
care rather than paternal care.
Kruger, D.J. & Nesse, R. M. (2004). Sexual selection and the Male: Female Mortality Ratio. Evolutionary
Psychology. 2, 66 - 85.
Continued…
 Historical changes significantly affected the
mortality rate:
 Decline of infectious diseases.
 Increase of mortality [in]directly caused by behavior
through:






Increase population size
Mobility
Domestication of animals
Public health measures
Medicine
Increase availability of tobacco, cars, weapons, etc.
Kruger, D.J. & Nesse, R. M. (2004). Sexual selection and the Male: Female Mortality Ratio. Evolutionary
Psychology. 2, 66 - 85.
Continued…
 In modern days:
 Male lifespan peak at young adulthood rather
than in later adulthood as in females;
 Highest differences for direct behavioral causes of
death
 Mortality is now due to more external
causes compared to earlier times.
Kruger, D.J. & Nesse, R. M. (2004). Sexual selection and the Male: Female Mortality Ratio. Evolutionary
Psychology. 2, 66 - 85.
Figure 1: 2000 M:F MR by Age and
Cause in the USA
QuickTi me™ and a
decompressor
are needed to see this pi cture.
Kruger, D.J. & Nesse, R. M. (2004). Sexual selection and the Male: Female Mortality Ratio. Evolutionary
Psychology. 2, 66 - 85.
Figure 2: Composition of Excess
Male Life Years Lost by Cause
QuickTime™ and a
decompressor
are needed to see this picture.
Kruger, D.J. & Nesse, R. M. (2004). Sexual selection and the Male: Female Mortality Ratio. Evolutionary
Psychology. 2, 66 - 85.
Figure 3: M:F MR in 2000 by Age in
20 Countries
QuickTime™ and a
decompressor
are needed to see this picture.
Kruger, D.J. & Nesse, R. M. (2004). Sexual selection and the Male: Female Mortality Ratio. Evolutionary
Psychology. 2, 66 - 85.
Time to test your knowledge!
Kruger, D.J. & Nesse, R. M. (2004). Sexual selection and the Male: Female Mortality Ratio. Evolutionary
Psychology. 2, 66 - 85.
1. This study examined the M:F MR over the course
of a lifespan in ___ countries.
a)
b)
c)
d)
10
5
20
15
2. Which one is NOT a historical or cultural
influence on M:F MR?
a)
b)
c)
d)
Domestication of animals
Availability of automobiles
Availability of antibiotics
Feminism
Kruger, D.J. & Nesse, R. M. (2004). Sexual selection and the Male: Female Mortality Ratio. Evolutionary
Psychology. 2, 66 - 85.
3. From an evolutionary perspective, why do
women generally outlive men?
a) Women are not wired to take any risks at all.
b) The survival of the offspring depends more on
maternal care.
c) Culture tells males to take more risks; the fact
that males take these risks has nothing to do
with evolution at all.
d) Actually, women DON’T out live males,
males outlive females.
Kruger, D.J. & Nesse, R. M. (2004). Sexual selection and the Male: Female Mortality Ratio. Evolutionary
Psychology. 2, 66 - 85.
4. In humans, females generally have a higher
mortality rate than males.
a) True
b) False
5. The results showed that the peak of external
causes for mortality rate in males generally
occurred during young adulthood.
a) True
b) False
6. M:F MR are exactly the same in all countries
examined in this study.
a) True
b) False
Kruger, D.J. & Nesse, R. M. (2004). Sexual selection and the Male: Female Mortality Ratio. Evolutionary
Psychology. 2, 66 - 85.