Anthro: FINAL EXAM
Adaptation
Both a process and a type of trait
Process whereby genetic changes occur over many generations in a population as a result of natural selection.
A process in which a genetic based trait increases in frequencies due to it being beneficial. it allows an individual to survive and reproductively successfully
Important note: this advantage is connected to a specific environment, which means if the environment changes, so does the advantage (adaptation)
Also the trait that results from these genetic changes
Adaptations can come from both the process and the result
Due to our ancestors we can exhibit these adaptations even if we don’t live in the area that adaptation came from. (Due to alleles (multi generational changes) passing from ancestors to generations)
Acclimatization
Long term changes that occur within one’s lifetime in response to environmental stress.
Developmental acclimatization: changes in organ or body structure during the growth of an organism. (Due to stress)
Usually permanent changes
Physiological acclimatization: physiological change that occurs over days or months (Response to stress)
Usually temporary. If the stressor goes away so does the change.
Acclimation
Short term physiological response to an environmental stress
Ways our bodies respond in the moments. This can occur quickly. For example, a person getting on a plane. Their breathing may begin to be deeper to get oxygen in the body.
Homeostasis
Maintenance of an equilibrium of various metabolic functions in the body
The chemical composition of the fluids in our body, body temp. Homeostasis helps maintain these things in our bodies.
Cold Responses
Acclimation
Increased metabolism
Shivering
If not fixed, things like frostbite and hypothermia can occur
Physiological acclimatization
Further metabolic increase
Increased red blood cell count
Vasoconstriction: In the face of extended cold, out blood vessels may constrict and move inwards in the body to conserve heat. (Help preserve core body temp) (both vasoconstriction and vasodilation occur)
Note: Vasodilation is
Cycling of heat to and from extremities (“hunting response”)
Adaptations
More compact body form
Shorter appendages
Rounder head shape
Narrow, high nasal aperture
Epicanthic eye folds and cheek pads
Helps keep face warmer
Light skin color?
Darker skin is prone to cold easily
Also culturally adaptation
In cold responses, both Allen’s rule and Berman’s rule play a part.
Heat Responses
Acclimation
Sweating
Cools the surface of the skin and encourages air to circulate around the skin.
Increased blood circulation to skin
Helps let heat escape
Physiological acclimatization:
Decreased heart rate
Helps the body cool easier
Increase plasma in blood
Helps prevent dehydration
Increased sweating
Adaptation
Elongated bodies
Longer appendages
Longer, narrower heads
Cultural adaptation
High Altitude responses
Oxygen pressure in the air is lower and this is significant because as we move up from the sea level air pressure decreases
The effect it has is that there is less oxygen pressure in the air, which makes it hard for the body to get oxygen.
Less oxygen leads to hypoxia because there is less oxygen in the blood cells/body
The responses we get from high altitude is biological in nature to humans
Acclimation
Increased respiration
Increased heart rate
Increased hemoglobin content in red blood cells
Physiological and developmental acclimatization
Increased number of capillaries
Increased lung size
Increased production of red blood cells
Respiration rate returns to normal
Enlarged right ventricle of heart
Babies born with lower birth weight
Adaptation
Larger chest circumference
Enlarged lung volumes
Lower hemoglobin concentration in blood
Greater cardiac output to brain and uterus (during pregnancy)
Less intro-uterine growth retardation
Birth weights closer to those at sea level
Slower growth growth rates during childhood and adolescence
Decreased incidence of Chronic Mountain sickness (CMS)
A condition that occurs especially in adults and elderly after living in high altitude for an extended amount of time if you didn’t grow up in the environment. If you have CMS, May experience headaches, dizziness, shortness of breath, and severe cases memory loss/death
This condition is a lot less prevalent for people who have adapted to living in high altitude for many generations and whose bodies have adapted in order to maintain homeostasis.
Summary
Variation in human traits may reflect the environment encountered during your lifetime
Acclimation
Acclimatization
Variations may also reflect natural selection for traits that were adaptive in your ancestors environment(s)
Adaptation
Adaptation
Both a process and a type of trait
Process whereby genetic changes occur over many generations in a population as a result of natural selection.
A process in which a genetic based trait increases in frequencies due to it being beneficial. it allows an individual to survive and reproductively successfully
Important note: this advantage is connected to a specific environment, which means if the environment changes, so does the advantage (adaptation)
Also the trait that results from these genetic changes
Adaptations can come from both the process and the result
Due to our ancestors we can exhibit these adaptations even if we don’t live in the area that adaptation came from. (Due to alleles (multi generational changes) passing from ancestors to generations)
Acclimatization
Long term changes that occur within one’s lifetime in response to environmental stress.
Developmental acclimatization: changes in organ or body structure during the growth of an organism. (Due to stress)
Usually permanent changes
Physiological acclimatization: physiological change that occurs over days or months (Response to stress)
Usually temporary. If the stressor goes away so does the change.
Acclimation
Short term physiological response to an environmental stress
Ways our bodies respond in the moments. This can occur quickly. For example, a person getting on a plane. Their breathing may begin to be deeper to get oxygen in the body.
Homeostasis
Maintenance of an equilibrium of various metabolic functions in the body
The chemical composition of the fluids in our body, body temp. Homeostasis helps maintain these things in our bodies.
Cold Responses
Acclimation
Increased metabolism
Shivering
If not fixed, things like frostbite and hypothermia can occur
Physiological acclimatization
Further metabolic increase
Increased red blood cell count
Vasoconstriction: In the face of extended cold, out blood vessels may constrict and move inwards in the body to conserve heat. (Help preserve core body temp) (both vasoconstriction and vasodilation occur)
Note: Vasodilation is
Cycling of heat to and from extremities (“hunting response”)
Adaptations
More compact body form
Shorter appendages
Rounder head shape
Narrow, high nasal aperture
Epicanthic eye folds and cheek pads
Helps keep face warmer
Light skin color?
Darker skin is prone to cold easily
Also culturally adaptation
In cold responses, both Allen’s rule and Berman’s rule play a part.
Heat Responses
Acclimation
Sweating
Cools the surface of the skin and encourages air to circulate around the skin.
Increased blood circulation to skin
Helps let heat escape
Physiological acclimatization:
Decreased heart rate
Helps the body cool easier
Increase plasma in blood
Helps prevent dehydration
Increased sweating
Adaptation
Elongated bodies
Longer appendages
Longer, narrower heads
Cultural adaptation
High Altitude responses
Oxygen pressure in the air is lower and this is significant because as we move up from the sea level air pressure decreases
The effect it has is that there is less oxygen pressure in the air, which makes it hard for the body to get oxygen.
Less oxygen leads to hypoxia because there is less oxygen in the blood cells/body
The responses we get from high altitude is biological in nature to humans
Acclimation
Increased respiration
Increased heart rate
Increased hemoglobin content in red blood cells
Physiological and developmental acclimatization
Increased number of capillaries
Increased lung size
Increased production of red blood cells
Respiration rate returns to normal
Enlarged right ventricle of heart
Babies born with lower birth weight
Adaptation
Larger chest circumference
Enlarged lung volumes
Lower hemoglobin concentration in blood
Greater cardiac output to brain and uterus (during pregnancy)
Less intro-uterine growth retardation
Birth weights closer to those at sea level
Slower growth growth rates during childhood and adolescence
Decreased incidence of Chronic Mountain sickness (CMS)
A condition that occurs especially in adults and elderly after living in high altitude for an extended amount of time if you didn’t grow up in the environment. If you have CMS, May experience headaches, dizziness, shortness of breath, and severe cases memory loss/death
This condition is a lot less prevalent for people who have adapted to living in high altitude for many generations and whose bodies have adapted in order to maintain homeostasis.
Summary
Variation in human traits may reflect the environment encountered during your lifetime
Acclimation
Acclimatization
Variations may also reflect natural selection for traits that were adaptive in your ancestors environment(s)
Adaptation