HA - what is adaptation?
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1
Define stress
Biological response to a stimulus that changes organism's normal/target state
2
6 types of physical stressors
Temp extremes
Altitude
Humidity
Light
Radiation
Pollutants
Altitude
Humidity
Light
Radiation
Pollutants
3
4 types of environmental stressors
Predators
Parasites
Pathogens
Deficiency/excess of specific nutrients
Parasites
Pathogens
Deficiency/excess of specific nutrients
4
3 types of social/cultural stressors
Resource competition
Mate competition
Conflict
Mate competition
Conflict
5
What factors does a stressor need to affect to cause adaptation?
Survival
Reproduction
Function
Reproduction
Function
6
Define adaptation
Adjustment in an organism enabling survival, reproduction and function
7
Difference between genotype and phenotype
Genotype = genetic sequency
Phenotype = observable characteristics
Phenotype = observable characteristics
8
Characteristics of homeostasis
Rapid
Reversible
Reversible
9
Charactersitics of acclimatisation
Modifies homeostatic response
Reversible
Phenotypic plasticity
Reversible
Phenotypic plasticity
10
Charactersitics of developmental platicity
Sensitive windows
Irreversible
Phenotypic plasticity
Irreversible
Phenotypic plasticity
11
Characteristics of natural selection
Heritable
Irreversible (at an individual level)
Irreversible (at an individual level)
12
Outline the 5 steps to a negative feedback loop
Stimulus - produces change in variable
Receptor - detects change
Input - info sent along afferent pathway to control centre
Output - info sent along efferent pathway to effector
Response - effector feeds back to influence magnitude of stimulus and returns variable to homeostasis
Receptor - detects change
Input - info sent along afferent pathway to control centre
Output - info sent along efferent pathway to effector
Response - effector feeds back to influence magnitude of stimulus and returns variable to homeostasis
13
Define acclimatisation
How an organims adapts to a change in environment
14
Characteristics of phenotypic plasticity
Relatively rapid
Reversible
Buffer genome
Reversible
Buffer genome
15
Give an example of developmental plasticity
Reduced growth in childhood as a result of acute/chronic malnutrition and/or poor health
Catch up growth possible with improvements in situation
Catch up growth possible with improvements in situation
16
When is growth most plastic in humans?
First 2 years of life
17
Humans have ________ genetic diversity
- low
- high
18
Where is modern genetic diversity highest?
Africa
19
What decreases with increasing distance from sub-Saharan Africa?
Genetic and morphological diversity
Eg. pelvic and cranial morphology
Eg. pelvic and cranial morphology
20
State 2 neutral evolutionary processes
Founder effect
Genetic bottleneck
Genetic bottleneck
21
Why does genetic and morphological diversity decrease with increasing diversity from Africa?
Serial founder effect
Genetic bottleneck
Genetic bottleneck
22
Define epigenetics
Heritable changes to gene expression without changes to the DNA base sequence
23
Outline 2 methods of creating microenvironments to increase survival
Modifying environment to suit biology - fast, flexible, potentially heritable and cumulative
Modifying biology to suit environment - natural selection, plasticity, slower, less flexible
Modifying biology to suit environment - natural selection, plasticity, slower, less flexible
24
Define ecological niche
Role of an organism in its ecosystem
Includes:
- Diet
- Predation
- Habitat
- Activity patterns
Includes:
- Diet
- Predation
- Habitat
- Activity patterns
25
Define genetic bottleneck
Occurs when population is greatly reduced in size, limiting the genetic diversity of the species
Caused by environemntal disaster, hunting to point of extinction, habitat destruction etc.
Caused by environemntal disaster, hunting to point of extinction, habitat destruction etc.
26
Define founder effect
Reduction in genomic variability
Occurs when small group of individuals becomes separated from larger population
New subpopulation has distinct traits different from the original larger population
Can be caused by geographic isolation
Occurs when small group of individuals becomes separated from larger population
New subpopulation has distinct traits different from the original larger population
Can be caused by geographic isolation
27
Difference between genetic bottleneck and founder effect
Genetic bottleneck = population sharply reduced in size by natural disaster
Founder effect = small group splits off from main population to found a colony
Founder effect = small group splits off from main population to found a colony