Question

11. You discover a new population of ashy geckos on the Dry Tortugas that have emigrated from southern Florida. You collect the genetic data in the table below for the enzyme cytochrome oxidase (cox), shown in the table below. a. What are the allelic frequencies for the Dry Tortugas population? b. What are the population’s genotypic frequencies? c. Is this population in H-W equilibrium? d. Offer an explanation (1-2 sentences) for your answer to 11c.

gecko #	Sex	cox genotype
1	M	c1c2
2	M	c1c1
3	F	c1c1
4	M	c2c2
5	F	c2c2
6	F	c1c1
7	M	c2c2
8	M	c2c2
9	F	c1c2
10	M	c1c1

Answer 1

The table in the question can be re- writtern as

Alleles	No. of Individuals
C1C1	4
C1C2	2
C2C2	4

A total of 10 Ashy jeckos on Dry Tortugas.

a) Allelic frequency of C1 = Total number of geckos with allele C1/ Total number of population

= 5 /10

= 0.5 (p)

( In genotype C1C2 half will be C1 nad half will be C2. sine there are total of 2 C1C2, one is C1 and 1 is C2. So 4 + 1 = 5)

Allele frequency of C2 = Toatal number of Jeckos with allele C2 / Total number of individuals

=5/10

=0.5 (q)

b) The genotypic frequency of C1C1 is p^2. ie., 0.5*0.5 = 0.25

The genotypic frequency of C2C2 is q² ie., 0.5 *0.5 = 0.25

The genotypic frequency of C1C2 is 2* p * q = 2*0.5*0.5

=0.5

c) Here, multiplying the genotypic frequency with that of total nuber of jeckos we get,

C1C1 = 0.25 * 10 = 2.5 = 2 ( As number of organisms are always expressed as whole number). But in actual 4 jeckos are observed with C1C1.

C2C2 = 0.25 *10 = 2.5 =2. But here also in observed data there is 4 jeckos with genotype C2C2.

C1C2 = 0.5 * 10 = 5 ; Whereas the observed number is 5.

Since the Observed and Expected values doesnot match, we can conclude that the population of Ashy Jeckos on dry Tortugas is not in Hardy- Weinberg Equilibrium.

d) The reasons for not obeying Hardy- Weinberg Equilibrium may be due to factors like, Small size of the Jecko population, Genetic drift, Migration, Mutation or may be due to the absence of random mating.