Variation and Stats Tests Flashcards
What are some examples of genetic features?
-Natural Eye Colour
-Hair Colour
-Blood Type
What are some examples of environmental features?
-Piercings / Tattoos
-Personality
-Language
-Sporting ability
Who are some examples of both environmental and genetic features?
-Height
-Skin Colour
What are the 2 types of variation?
-Intraspecific
-Interspecific
What is Intraspecific Variation?
Differences in characteristics within a species
What is Intraspecific Variation created by?
Mutations within a species or variation occurring during reproduction
What does this mean for species/variation if its created by variation?
-Only fittest individuals survive to breed
-This variation is acted upon by selection pressures
(Is the way evolution via natural selection operates)
What is Interspecific Variation?
Differences in characteristics between different species e.g. grizzly bear vs polar bear
What differences can be this variation due to?
Genetic or behavioural
What is continuous variation?
Variation which is smooth and falls along a line e.g. height
What is discontinuous variation?
Variation that can only be one of a few categories with no in between values e.g. blood type
How is continuous variation usually presented?
In a bell shaped curve which is the normal distribution
What is the value of normal distribution?
68.2%
What is Standard Deviation a Measure of?
How spread out the data is
What 2 things does a greater standard deviation represent?
-Greater spread of data
-Characteristic with greater variation
What can the t-test tell you?
If there is a statistically significant difference between two means when:
-sample size less than 25
-data is normally distributed
What does HO mean in relation to the null hypothesis?
No statistically significant difference
What does HA mean in relation to the null hypothesis?
Significant difference
Define Correlation.
The degree to which two variables are related
What value is a perfect positive correlation?
1
What value is a high positive correlation?
0.9
What value is a low positive correlation?
0.5
What value is no correlation?
0
What value is a perfect negative correlation?
-1
What value is a high negative correlation?
-0.9
What value is a low negative correlation?
-0.5
What does spearmen’s rank tell us?
If there is a statistically significant correlation between the measurements from the same sample (5-30 pairs of data)
What does spearmen’s rank also tell us?
If the correlation is positive or negative
