DNA vs Space – a beauty pageant

We invest a ton of resources trying to understand space. Understandable considering that it pays off in more ways than you can count. Understanding space (and all aspects of reality) is part of our human desire and need to know things. Most importantly though, it gives pretty pictures! Look at the picture below. It represents the universe at an age of 1/14 of what it is today. Translating that to human years (if today is a really old person) would be about 6 years of age, or more exactly 0.4 to 0.8 out of a total of 13.8 billion years.

Figure 1. The Universe at 400 million years (click for more information).

Look at the picture below. It might not be as colorful and pretty. But it is kind of gorgeous. It represents small stretch of DNA, which if extended (uncoiled, and pulled really hard) is about 0.3 mm in length. Translating that to human years is harder, but it is about twice as thick a human hair.

DNA genes illustration
Figure 2. Our DNA, part of which are the same as what it was 3.6 billion years ago (click to go to interactive source).

So what are we looking at? This is the free and publicly available, 18th version of what we think is the human genome. The scale bar at the top shows 10 mega-base pairs i.e. 10 000 000 ACTG. Underneath the scale bar you can see a bunch of abbreviations representing genes, where their length in proportional to number base pairs. Genes are the equivalent of chapters in a cookbook. But instead of containing recipes for food, they contain the recipes for making proteins. I have highlighted three genes. The TAS1R2 gene is the recipe for making one part of the receptors that detect sweet taste on our tounges. Cats have actually lost this receptor in the course of their evolution, making sweets about as interesting as potato peals to them. Next to it you will find the cryptically named ALDH1A1 genes. This has the instructions to make a protein that is part of the family of enzymes responsible for breaking down alcohol. Without these proteins, getting drunk would be a dangerous and long-term affair. Finally to the far left, is the NBL1 gene, part of the awesomely named cerberous protein family. These proteins regulate the shape of our bodies, and more specifically head formation during embryo development. So which of the two pictures is prettier? Well its like comparing to pineapples to oranges. They are different.

They cover different scales. One covers the macro, the light years of distances and aeons of travel. The other covers the micro, the infinitesimal spaces where genes reside. At the same time they are actually extremely similar. They both give us hints about the distant past. The space picture represents the universe at its childhood, while the DNA schematic has hints of its childhood. Meaning? Few proteins are really unique. They all share common ancestors if you trace back long enough, and different version are found in different organisms. So really, some parts of our DNA are probably identical in both us and in the first living organism (with DNA).

More importantly though, they represent the pinnacle of human technology: the investment of huge resources, the collaboration among different nations, and our curiosity, crystallized.

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