Evolutionary Darwinian Medicine
Evolutionary (Darwinian) Medicine
“Nothing in biology makes sense except in the light of evolution” –Theodosius Dobzhansky
Proximate vs. Ultimate Questions
Biological causation: proximate vs. ultimate explanations
Physiology, genetics, biochemistry, etc. generally concentrate on * proximate causation
“What” & “How” questions
Ultimate causation: How evolutionary processes (natural selection; adaptation) and evolutionary history shape traits
“Why” questions
Traits have both types of causes—a complete biological explanation requires analysis of both
Examples: Childbirth, obesity, high blood pressure and asthma/allergy
The Big Picture: Hominid Origins
What are the key features that define us as humans & when did they …show more content…
Malthus (1766-1834)
An Essay on the Principle of Population
Human population size can’t increase indefinitely because of limited …show more content…
Defenses
2. Infectious Organisms & Evolutionary Arms Races
3. Novel Environments
4. Genes
5. Compromises
6. Constraints & Evolutionary Legacies
1. Defenses
Not actually causes but evolved defenses; can be confused with manifestations of disease
e.g., pain, fever, cough, nausea, vomiting, sneezing, anxiety, morning sickness
Decisions on when to block these defenses7
Evidence that fever (rise in the set point of the body’s thermostat) is an adaptation
Speeds up immunological reactions and reduces reproductive rate in many pathogens
Fever is adaptive against some pathogens
Lizards: move to warmer locations to increase body temperature
Humans: Some evidence that fever is adaptive against colds (rhinovirus) and syphilis
But fever has costs (e.g., metabolic & cell damage)
Bad idea to always suppress fever; very high fever can be bad
Reducing fever generally does not lead to faster recovery times or increased comfort while sick “Fever, as a mechanism that activates the immune system to cure us of the pathogen, is a defense, a tool on our side, and the best way to control an illness is to leave the fever alone, at least some and perhaps most of the time.” - Zuk
“Nothing in biology makes sense except in the light of evolution” –Theodosius Dobzhansky
Proximate vs. Ultimate Questions
Biological causation: proximate vs. ultimate explanations
Physiology, genetics, biochemistry, etc. generally concentrate on * proximate causation
“What” & “How” questions
Ultimate causation: How evolutionary processes (natural selection; adaptation) and evolutionary history shape traits
“Why” questions
Traits have both types of causes—a complete biological explanation requires analysis of both
Examples: Childbirth, obesity, high blood pressure and asthma/allergy
The Big Picture: Hominid Origins
What are the key features that define us as humans & when did they …show more content…
Malthus (1766-1834)
An Essay on the Principle of Population
Human population size can’t increase indefinitely because of limited …show more content…
Defenses
2. Infectious Organisms & Evolutionary Arms Races
3. Novel Environments
4. Genes
5. Compromises
6. Constraints & Evolutionary Legacies
1. Defenses
Not actually causes but evolved defenses; can be confused with manifestations of disease
e.g., pain, fever, cough, nausea, vomiting, sneezing, anxiety, morning sickness
Decisions on when to block these defenses7
Evidence that fever (rise in the set point of the body’s thermostat) is an adaptation
Speeds up immunological reactions and reduces reproductive rate in many pathogens
Fever is adaptive against some pathogens
Lizards: move to warmer locations to increase body temperature
Humans: Some evidence that fever is adaptive against colds (rhinovirus) and syphilis
But fever has costs (e.g., metabolic & cell damage)
Bad idea to always suppress fever; very high fever can be bad
Reducing fever generally does not lead to faster recovery times or increased comfort while sick “Fever, as a mechanism that activates the immune system to cure us of the pathogen, is a defense, a tool on our side, and the best way to control an illness is to leave the fever alone, at least some and perhaps most of the time.” - Zuk