Wizarding Genetics
Ever wondered how magical genetics worked? This is a guide that should help you understand. *This isn't mine and all the original research is linked in the bibliography
Last Updated
05/31/21
Chapters
4
Reads
1,185
Phenotypes In Harry Potter
Chapter 2
The stuff covered in this chapter is simple and has almost nothing to do with magic, it simply looks at the physical appearances of certain families in the wizarding world to familiarize the student with genetic terms and information.
The Weasley Family
It is said that the entire Weasley family has red hair and freckles. We will look at genetic information on these two traits.
Freckles
There are two possible phenotypes for freckles, has freckles or doesn't.
A genotype for freckles is indicated by two alleles in the freckle gene. The possible alleles using the first letter of the trait “f” are:
F (dominant) = Has Freckles
f (recessive) = No freckles
| Genotype | Phenotype |
| FF | has freckles |
| Ff | has freckles |
| ff | no freckles |
Red hair colour is recessive to brown colour.
| Genotype | Phenotype |
| RR | Brown hair |
| Rr | Brown hair |
| rr | Red hair |
Example 1:
Mom has freckles, Dad does not and both have a homozygous genotype.
Mom: FF
Dad : ff
| F | F | |
| f | Ff | Ff |
| f | Ff | Ff |
Example 2:
Both Mom and Dad have freckles but are both heterozygous
Mom: Ff
Dad: Ff
| F | f | |
| F | FF | Ff |
| f | Ff | ff |
Now onto the Weasley family
Using the information we have gathered we can infer the genotypes of Molly and Arthur Weasley for these two traits.
All Weasley children have freckles and red hair—100% probability.
Possible genotypes for their red hair (recessive trait) and freckles
(dominant trait) are: rr only for red hair and Ff or FF for freckles.
Both parents have rr
| rr | rr |
| rr | rr |
| Ff | Ff |
| Ff | Ff |
| FF | FF |
| FF | FF |
In this section we will advance just a bit, finding the possible genotypes of the Potters and the possible genotypes of Harry' children when he marries Ginny Weasley.
Harry has dark hair like his father and his mother has red hair.
| Name | Phenotype and Genotype |
| James Potter (father) | Dark hair (Rr or RR) |
| Lily Potter (mother) | Red hair (rr) |
| Harry Potter (son) | Dark hair |
| rr | rr | |
| R | Rr | Rr |
| r | rr | rr |
| r | r | |
| R | Rr | Rr |
| R | Rr | Rr |
Harry marries Ginny, what are their possible genotypes?
Harry = Rr
Ginny = rr
| r | r | |
| R | Rr | Rr |
| r | rr | rr |
