The process in which new species develop from earlier forms.

Normally occurs slowly, most often in response to a change in a species’ environment.

The process in which new species develop from earlier forms. Normally occurs slowly, most often in response to a change in a species’ environment. Life is thought to have evolved from just a few unicellular organisms three billion years ago.

The process in which new species develop from earlier forms. Normally occurs slowly, most often in response to a change in a species’ environment. Life is thought to have evolved from just a few unicellular organisms three billion years ago. Evolution happens through ‘changes in the frequency of alleles in a population’ – some alleles do better than others.

The process in which new species develop from earlier forms. Normally occurs slowly, most often in response to a change in a species’ environment. Life is thought to have evolved from just a few unicellular organisms three billion years ago. Evolution happens through ‘changes in the frequency of alleles in a population’ – some alleles do better than others. Freq. of an allele = occurrence of that allele total number of alleles

Suppose a gene pool were to contain 50 individuals.

30 – Aa, 10 – AA and 10 – aa

Suppose a gene pool were to contain 50 individuals. 30 – Aa, 10 – AA and 10 – aa For the A allele it occurs 30 times from Aa

Suppose a gene pool were to contain 50 individuals. 30 – Aa, 10 – AA and 10 – aa For the A allele it occurs 30 times from Aa The A allele also occurs 20 times from AA (2x10)

Suppose a gene pool were to contain 50 individuals. 30 – Aa, 10 – AA and 10 – aa For the A allele it occurs 30 times from Aa The A allele also occurs 20 times from AA (2x10) The occurrence of the A allele is now 50 ( )

Suppose a gene pool were to contain 50 individuals. 30 – Aa, 10 – AA and 10 – aa For the A allele it occurs 30 times from Aa The A allele also occurs 20 times from AA (2x10) The occurrence of the A allele is now 50 ( ) There are 50 individuals with two alleles so that the total number of alleles is 100 (50x2)

Suppose a gene pool were to contain 50 individuals. 30 – Aa, 10 – AA and 10 – aa For the A allele it occurs 30 times from Aa The A allele also occurs 20 times from AA (2x10) The occurrence of the A allele is now 50 ( ) There are 50 individuals with two alleles so that the total number of alleles is 100 (50x2) Frequency of the A allele = 50/100 = 0.5

1.Suppose a gene pool were to contain 60 individuals. 20 were BB, 30 were Bb and 10 were bb. Calculate the frequency of the B allele. 2.A gene pool has 120 individuals. 60 were Aa, 20 were AA and 40 were aa. Calculate the frequency of the A allele.

Sometimes the recessive allele is bad because it makes the individuals phenotypically inferior in some way.

Remembering we have 50 indiv. = 30 Aa, 10AA, and 10 aa

Sometimes the recessive allele is bad because it makes the individuals phenotypically inferior in some way. Remembering we have 50 indiv. = 30 Aa, 10AA, and 10 aa If all the 10 individuals that showed this allele died or were forced to leave the population then:

Sometimes the recessive allele is bad because it makes the individuals phenotypically inferior in some way. Remembering we have 50 indiv. = 30 Aa, 10AA, and 10 aa If all the 10 individuals that showed this allele died or were forced to leave the population then: Numerator is found from the Aa indiv. (30x1) = 30 a alleles

Sometimes the recessive allele is bad because it makes the individuals phenotypically inferior in some way. Remembering we have 50 indiv. = 30 Aa, 10AA, and 10 aa If all the 10 individuals that showed this allele died or were forced to leave the population then: Numerator is found from the Aa indiv. (30x1) = 30 a alleles Denominator is found from the 30 Aa individuals + the 10 AA individuals (30x2 + 10x2 = 80) – total alleles.

Sometimes the recessive allele is bad because it makes the individuals phenotypically inferior in some way. Remembering we have 50 indiv. = 30 Aa, 10AA, and 10 aa If all the 10 individuals that showed this allele died or were forced to leave the population then: Numerator is found from the Aa indiv. (30x1) = 30 a alleles Denominator is found from the 30 Aa individuals + the 10 AA individuals (30x2 + 10x2 = 80) – total alleles. The frequency is now 30/80 = – evolution is operating because there has been a change in allele frequencies.

Sickle-cell anaemia – red blood cells form a sickle shape. These abnormally shaped cells cause severe muscle pain and in extreme cases, death.

Cystic fibrosis – carried by 1 in 20 pakeha. The affected individual secretes abnormally thick mucus. This affects both their digestive and respiratory systems. In the lungs it provides a thick breeding ground for bacteria.