Believe it or not, all of us are related! Although many people might find this unbelievable, science proves that all living beings on earth are related to each other based on mathematical and genetic grounds, if you dig up enough of history.
In 2013, Peter Ralph from USC Dornsife which is a university in Southern California utilized a unique methodology to study human evolution. He made use of mathematics, statistics, and data analysis of genomic data to deeply study human demographics and evolution. Together with Graham Coop, a geneticist at the University of California, Ralph presented DNA-based evidence to prove that somewhere down the hierarchy, every earthling is related to each other.
In an interview with phys.org, Ralph explained the science behind this phenomenon in a very interesting manner. Every living being has two parents. This suggests that the ancestor-count for each individual becomes twice every year. Basic mathematical calculations show that ten generations ago, every individual had 1000 ancestors. Twenty generations ago, each individual had a million ancestors, and so on.
But the most interesting part is that when we get to 40 generations in the past, which is the time of Charlemagne, the ancestor-count reaches a trillion. Now, this is a problem. At this point, the number of ancestors exceeds the number of people. From this observation, we can arrive at the conclusion that the majority of those ancestors must be the same person.
To better understand this, consider a family tree. Initially, it appears as a normal tree, while the branches double with every new generation. However, it doesn’t take a long time for the branches to crash into one another. When this happens, the branches resemble a web-like tapestry. This is what happens when distant cousins get married and share a set of distant grandparents. In other words, most people in Western Europe are unknowingly tying the knot with their 30th cousin.
This study was published in 1999 by Joseph Chang, a Yale statistician. He states: “All individuals who have any descendants among the present-day individuals are actually ancestors of all present-day individuals”. In simple terms, this study draws the conclusion that all of us must share a common ancestor.
The genetic research carried out by Ralph and Coop is mainly focused on Europe, and they succeeded in solidifying Chang’s declarations. Ralph stated that how closely or distantly two people are related can be identified by the length of a shared DNA sequence. Therefore, we share the longest DNA sequence with our parents. The length of the DNA sequence shared with our grandparents is half as long as the one share with parents, and so on. In conclusion, when the ancestors become more distant, the chunk of shared DNA becomes shorter.
Isn’t it mindblowing to know that all humans are related to each other? Let us know your thoughts in the comments.