DNA soup

"Imagine having an international potluck supper, where everyone invited is asked to bring a soup that is specific to his or her own country. In our kitchen we have several dozen bowls of soup sitting on the table. Each has a slightly different recipe, but they all come from the same source. How do we know this? Because each recipe uses as its basic ingredient impala- a species of antelope that offurs naturally only in Africa. It is extremely difficult to obtain impala meat in many parts of the worls, but it is the cornerstone of all soup recipes and it must be included. As we taste the soups we begin to detect another pattern. Some contain black pepper, while others contain salt. There are the two main soup categories, and if you don't have one you don't have the other. There are many additional variants among the soup recipes- some with fish, others with barley, a few with unusual spices you can't identify- but they are all united by the presence of salt. Similarly the black pepper recipes have a huge range of additional ingredients- thyme, berries, pork, nuts- but they all contain black pepper."

So basically, we all have the same soup base (DNA code), but as we change from region to region we each have different ingredients (genes) which make our soups (DNA sequences and our phenotypes) different.

I like this analogy of soup to show the lineage of genes. Just like the chef and the recipes analogy in DNA replication, this helped me understand what the Y-chromosome markers meant and how they were different.