…or Mommy, where did Finntroll come from?
Everybody knows Vikings are cool—cooler than pirates, maybe—but I doubt that many people outside the underground metal scene know much about Viking metal. I’ll get into that soon, but first we need to talk about Vikings. We are going to use genetics to trace humankind’s prehistoric route from Africa to Scandinavia and beyond. Then we will see if we can do something similar with Viking metal. It won’t be scientific but it will be close enough for rock & roll.
Geneticists have recently started analyzing how differences between genes in different populations can show how people migrated across the planet. They have sorted hundreds of thousands of people into groups based on these differences. Then, knowing where those people live or where their recent ancestors lived, they can figure out how we have moved around.
Let’s go (back) to high school for a little while. We need to remember a few things before we can get into the cool stuff. I am going to skip the stuff we don’t need to know here. A good place to look for more info is in this Wikipedia article.
The smallest chunk of genetic material is a nucleotide. You can think of a nucleotide as a letter. The four nucleotides are abbreviated G, C, A, and T. See, even scientists think of them as letters. Nucleotides pair up. G pairs with C. A pairs with T. Nucleotides are also called bases so a pair of nucleotides is called a base pair.
String a number of base pairs together and you get a gene. A gene contains enough information to tell your body how to make a specific protein. Proteins do things for you. Each protein does a different thing.
String a bunch of genes together and you get a DNA molecule. The DNA molecule twists up into structure called a chromosome. Chromosomes also come in pairs. If you, the reader, are a human you have 46 chromosomes in 23 pair.
I would like to pretend you are female because it makes this illustration simpler. If you identify with that Who song “I’m a Boy,” you can go back to being male soon.
Each egg cell you produce will contain only 23 chromosomes—not 46. That’s exactly how you want it. If an egg cell “gets lucky” (hopefully with a sperm cell from another consenting adult), it will combine with the sperm’s 23 chromosomes to create an embryo with a total of 46 chromosomes.
So how does your body decide which 23 of your 46 chromosomes go into the egg? It wimps out and includes material from all 46. The chromosomes are in pairs, right? Each chromosome in your egg cell contains a mixture of segments of DNA from each chromosome in your corresponding pair. The mixture is different in different egg cells. If you were into hip hop a few years ago, you might call this mixing “chopped and screwed.”
Take any of your chromosome pairs as an example. One chromosome came from your mother and contains a mixture of DNA from her parents. The other chromosome came from your father and likewise, it contains a mixture of DNA from his parents. Your egg cells therefore will contain a mixture of DNA from all four of your grandparents. The same thing will be true of any sperm that happens to fertilize your egg.
The end result is that (most) DNA gets really mixed up after just a few generations. It’s too mixed up to be of use here. Luckily, there are two exceptions.
You can be male again now. Turn off your Ray Lamontagne CD and listen to some AC/DC if you need help with the transition.
When you create sperm only 22 of your 23 chromosome pairs are “chopped and screwed.” Only one of your last chromosome pair is passed on and it is passed on pretty much exactly as you got it from one of your parents. This final chromosome is the one that determines gender. Some of your sperm will have the chromosome you got from your father. Sometimes this is referred to as a Y chromosome because it looks like a Y. The rest will have the one you got from your mother. It looks like an X.
Males have one X and one Y chromosome and either one could end up in a sperm cell. Females have two X chromosomes so no matter what they will pass along an X chromosome. The DNA on the X chromosome in each egg is a mixture of the DNA from the mother’s two X chromosomes.
Since you are male, your daughters will receive an almost perfect copy of your X chromosome. Your X chromosome came from your mother. Remember that when she made her eggs, the X chromosome that would become your was a mixture of your mother’s two X chromosomes. It went through the same mixing process described above, so it’s not useful for our purpose here.
It is important to understand that your sons will inherit a Y chromosome that is almost exactly like your paternal grandfather’s Y chromosome. His Y chromosome was almost exactly like his father’s father’s father’s father’s Y chromosome. I say “almost exactly” because the DNA copying process isn’t perfect and errors are made. This is also very important and I will discuss it in more detail later.
So even though I have no idea when I last hugged my dad, we are connected by this DNA thread that leads through all our male ancestors back into prehistory. Women are better at bonding anyway, but is this one way they are ripped off? NO! They have a similar DNA link but it’s even cooler. I’ll get into that in a future post. I promise that when I explain it you will think I made it up.