Some people in the magical world value muggles. Many ignore them and live in their own worlds. Few even look down upon muggles and treat them like vermin. Whatever the case may be, it is undoubtable that muggles have some knowledge on science and biology that we wizards and witches simply do not have. What muggles call modern genetics may just be the key to proving the theory of magical ancestry. 

First, to understand this lesson, one must first understand what modern genetics are. Modern genetics are the study of DNA inside of our bodies that create traits for us. These traits are also known as genes, and it is these genes that influence our traits like hair or eye color. These genes have dominant or recessive alleles. For each trait in your body, you will have two alleles for it. You have 46 chromosomes in your body, but only 23 in gamete cells. That is because when gamete cells meet it will make a 46-celled offspring. Because only half of the chromosomes are passed down from each parent, that leads to only one allele for each trait being passed down. Two more good vocabulary words are homozygous and heterozygous. Homozygous is when someone has two of the same alleles, and heterozygous is one of each. So someone’s eye color allele may be Ee, meaning it would be the dominant allele. All of this muggle biology nonsense may just prove magical ancestry. 

So how is magic passed down? In what some people would call a “pure-blood” family, the offspring are somehow guaranteed to be a witch or wizard. If a wizard or witch were to marry a muggle and have a child, it is unclear if the offspring would be magical or not. However, in a “no-mag” family, an offspring may still have magical capabilities. So how is this possible?

Before trying to prove alleles and all that, one must first discover if having magic is the dominant or recessive allele. To save time from tests and all of that, it is clear that being a witch or wizard is the recessive allele. So to look at an allele standpoint, being a muggle will be known as M and being magical will be known as m.

To make this more simple, it is best to eliminate squib’s from the equation for now. Because of this we will be assuming absolute dominance, or saying that if a dominant trait is present in offspring then they will portray the dominant trait. We will be testing this using a Punnett Square, or an idea that the alleles will cross in a four by four table finding the new pairs of alleles. 

So let's begin testing with pure bloods. To be magical, one must have an allele pair of mm. So if two pure bloods are marrying, the test-cross of alleles would be mm x mm. This would have a 100% rate of having a magical offspring, proving how pure-blooded families like the Malfoy’s always have a magical child. This is why wizards will often marry between themselves, forcing the offspring to hold magic. 

As for a half-blood, there are a few possibilities. One parent must be a witch or wizard, making their allele pair mm. As for the other parent, they must be a muggle, making theirs MM or Mm. Because we are assuming absolute dominance, a muggle can have a Mm allele pair and will still be a muggle because the M covers up the m. So the cross would have to be either mm x MM or mm x Mm. In the case of mm x MM, the offspring will either be a muggle or squib. To quickly touch on a squib, this would be a Mm pair but would not assume absolute dominance. Because of not assuming absolute dominance, they would still have some magical power but not as much as an absolute dominant wizard or witch. If it is mm x Mm, the offspring can either be a muggle, squib, or magical. That just comes down to if the pair is Mm (squib or muggle) or mm (magical) and if assuming absolute dominance. 

As for a muggle born, this is where it gets interesting. If both parents are muggles, then the allele pairs must be MM or Mm. Even if it is a squib, that does not affect the situation. If either one parent is MM, then the offspring cannot be a magical being. However if both parents are Mm, then there is a 25% chance that the offspring will hold magic. There is also a 50% in that match who will have an Mm offspring, which can lead to more muggle born wizards. 

So for those who believe muggles are useless, here is a whole article on how they are not. This may be confusing to some of you who have not yet studied biology, but I may write a series of articles explaining this in more depth. This is a very surface level article without diving into the depths of genetic variations or more, but I tried to keep it simple. This is a very complex theory that has now been revealed that I am coining the Magical-Genetic Theorem.