Simple Genetics
Many thanks to Neville Collins for these articles.
Simple Explanation of Genetics
Many people seem have trouble understanding the basic principle of genetic inheritance because it is usually expressed in a complicated way. I shall try and explain it in a simple way
If you mate a green budgie to a blue budgie you will get a green bird that is split to blue because green is dominant. This bird is described as green/blue (the slash “/” means split The part before the slash is the visible part, after the slash are the hidden genes)
If you mate two green/blue birds together you will get greens that are not split, greens that are split and blues.
It works like this:
Male Green/blue
Female Green/blue
The chicks take half from each parent
So the 1st chick takes the green from the male and the green from the female, it is a green that is not split. (Green/Green)
The 2nd chick takes the green from the male and the blue from the female, it is a green bird that is split to blue (Green/Blue)
The 3rd chick takes the blue from the male and the green from the female, so it is also a green bird split to blue (Green/Blue) (green being dominant)
The 4th chick takes the blue from the male and the blue from the female, so it is a blue bird. (Blue/Blue)
Each of these 4 chicks represents 25% of the clutch so we can expect 25% green, 50% Green/blue & 25% blue (Note: They will come in random order and you may get several of 1 type before you get any of another)
The green birds that are split will look exactly the same as the green birds that are not split but when you breed them you will get a different result
This pattern works exactly the same with any dominant mutation paired with a recessive mutation
Example: with Spangles which are dominant to normal (you wouldn’t usually refer to them as split but remember that they got 1 part from each parent)
Male Spangle/Normal
Female Normal/Normal
1st chick – Spangle/Normal
2nd chick – Spangle/Normal
3rd chick – Normal/Normal
4th chick – Normal/Normal
%50% Spangle, 50% Normal
example: Greywing which are recessive to Normals
Male Greywing/Greywing
Female Normal/Normal
1st chick – Normal/Greywing (Normal being dominant)
2nd chick - Normal/Greywing
3rd chick - Normal/Greywing
4th chick - Normal/Greywing
100% Normal/Greywing. These birds all look normal but because they are split to greywing if they are mated to another bird that has greywing genes they will produce greywings
The sex linked mutations work a bit differently.
If this is any help to anyone then I’ll try and explain the sex linked mutations, the dark factor, combined mutations and double factors some other time.
If you mate a green budgie to a blue budgie you will get a green bird that is split to blue because green is dominant. This bird is described as green/blue (the slash “/” means split The part before the slash is the visible part, after the slash are the hidden genes)
If you mate two green/blue birds together you will get greens that are not split, greens that are split and blues.
It works like this:
Male Green/blue
Female Green/blue
The chicks take half from each parent
So the 1st chick takes the green from the male and the green from the female, it is a green that is not split. (Green/Green)
The 2nd chick takes the green from the male and the blue from the female, it is a green bird that is split to blue (Green/Blue)
The 3rd chick takes the blue from the male and the green from the female, so it is also a green bird split to blue (Green/Blue) (green being dominant)
The 4th chick takes the blue from the male and the blue from the female, so it is a blue bird. (Blue/Blue)
Each of these 4 chicks represents 25% of the clutch so we can expect 25% green, 50% Green/blue & 25% blue (Note: They will come in random order and you may get several of 1 type before you get any of another)
The green birds that are split will look exactly the same as the green birds that are not split but when you breed them you will get a different result
This pattern works exactly the same with any dominant mutation paired with a recessive mutation
Example: with Spangles which are dominant to normal (you wouldn’t usually refer to them as split but remember that they got 1 part from each parent)
Male Spangle/Normal
Female Normal/Normal
1st chick – Spangle/Normal
2nd chick – Spangle/Normal
3rd chick – Normal/Normal
4th chick – Normal/Normal
%50% Spangle, 50% Normal
example: Greywing which are recessive to Normals
Male Greywing/Greywing
Female Normal/Normal
1st chick – Normal/Greywing (Normal being dominant)
2nd chick - Normal/Greywing
3rd chick - Normal/Greywing
4th chick - Normal/Greywing
100% Normal/Greywing. These birds all look normal but because they are split to greywing if they are mated to another bird that has greywing genes they will produce greywings
The sex linked mutations work a bit differently.
If this is any help to anyone then I’ll try and explain the sex linked mutations, the dark factor, combined mutations and double factors some other time.
Many thanks Neville and we look forward to more of your simple genetics.
The Dark Factor
A Simple Explanation of the Dark Factor
I shall attempt to explain how the dark factor works without going into any complicated reasons
All budgies have a dark factor rating. It is either 0, 1 or 2. This affects the base colour regardless of what mutation the birds are
0 dark factors appear as sky blue or light green
1 dark factor appears as cobalt or dark green
2 dark factors appear as mauve or olive
If you pair two birds with 0 dark factors together the chicks will also have 0 dark factors. It doesn’t matter whether they are both sky blues or both light greens or one of each
If two birds with 1 dark factor are paired together the result will be 50% 1 dark factor, 25% 0 dark factor and 25% 2 dark factors
If two birds with 2 dark factors are paired together all the chicks will also have 2 dark factors
If a 0 dark factor bird is mated to a 1 dark factor bird the result will be 50% with 0 dark factors, 50% with 1 dark factor
If a 1 dark factor bird is mated to a 2 dark factor bird the result will be 50% 1 dark factor, 50% 2 dark factors
If a 0 dark factor bird is mated to a 2 dark factor bird the result will be 100% 1 dark factor chicks
Mutations like albinos, lutinos, greys and others where the dark factor rating may not be visible still have a dark factor rating but it might be only possible to tell what it is by breeding.
e.g. If a mauve cock bird (2 dark factors) was mated to a lutino hen and the chicks were all dark greens and/or cobalts (1 dark factor) it would prove that the lutino’s dark factor rating was 0. If however the chicks were a mixture of cobalts, mauves, dark greens and olives, the lutinos rating would be 1 dark factor. If they were all mauves & olives her rating would be 2 dark factors.
Mating a bird with 2 dark factors with a bird with any other rating can not possibly produce chicks with 0 dark factors. Also mating a bird with 0 dark factors with a bird with any other rating can not produce chicks with 2 dark factors. This means that a sky blue cannot have a mauve parent and an olive can not have a light green parent.
All budgies have a dark factor rating. It is either 0, 1 or 2. This affects the base colour regardless of what mutation the birds are
0 dark factors appear as sky blue or light green
1 dark factor appears as cobalt or dark green
2 dark factors appear as mauve or olive
If you pair two birds with 0 dark factors together the chicks will also have 0 dark factors. It doesn’t matter whether they are both sky blues or both light greens or one of each
If two birds with 1 dark factor are paired together the result will be 50% 1 dark factor, 25% 0 dark factor and 25% 2 dark factors
If two birds with 2 dark factors are paired together all the chicks will also have 2 dark factors
If a 0 dark factor bird is mated to a 1 dark factor bird the result will be 50% with 0 dark factors, 50% with 1 dark factor
If a 1 dark factor bird is mated to a 2 dark factor bird the result will be 50% 1 dark factor, 50% 2 dark factors
If a 0 dark factor bird is mated to a 2 dark factor bird the result will be 100% 1 dark factor chicks
Mutations like albinos, lutinos, greys and others where the dark factor rating may not be visible still have a dark factor rating but it might be only possible to tell what it is by breeding.
e.g. If a mauve cock bird (2 dark factors) was mated to a lutino hen and the chicks were all dark greens and/or cobalts (1 dark factor) it would prove that the lutino’s dark factor rating was 0. If however the chicks were a mixture of cobalts, mauves, dark greens and olives, the lutinos rating would be 1 dark factor. If they were all mauves & olives her rating would be 2 dark factors.
Mating a bird with 2 dark factors with a bird with any other rating can not possibly produce chicks with 0 dark factors. Also mating a bird with 0 dark factors with a bird with any other rating can not produce chicks with 2 dark factors. This means that a sky blue cannot have a mauve parent and an olive can not have a light green parent.
Many thanks Neville.