Statistical Tests

Question 1

Chi squared equation

Answer 1

X^2 = the sum of (observed - expected)^2
/ expected

Question 2

What does the chi squared test achieve?

Answer 2

-whether the difference between observed and expected results is small enough to occur purely due to chance

Question 3

What data is the chi test used for?

Answer 3

-discontinuous variation data - raw counts

Question 4

What does the chi test determine?

Answer 4

-if the null hypothesis is correct

Question 5

What do you do with the value obtained?

Answer 5

-compare to the critical value
-if less than CR then null hypothesis is accepted as the difference due to chance is not significant

Question 6

What is the Hardy-Weinberg principle?

Answer 6

-used to estimate the frequency of alleles in a population
-see if a change in allele frequency is occurring in a population over time

Question 7

Hardy Weinberg principle

Answer 7

• p^2 + 2pq + q^2 = 1

Question 8

When is Hardy Weinberg principle accurate?

Answer 8

-when population is in equilibrium
-percentages aren’t changing from one generation to the next
-can compare to actual genotypes to tell if the population is changing

Question 9

What are the assumptions of the Hardy Weinberg principle?

Answer 9

1. Large population size
2. Random mating
3. No mutations
4. No selection pressures = no evolution