Take a look around you. What do you see? Are you in a room with other people? Or maybe you’re home alone with your dog or cat? Look a bit harder, and you might notice some ants crawling on your kitchen sink. Use a microscope, and you can see protozoa and bacteria. The world is teeming with life, and we’re all related somehow. The first phylogenetic tree was based on Darwin’s theory of evolution. As technology advanced and genetic sequencing became common, modern-day scientists improved and rearranged the phylogenetic tree.
The Alphabet We Share
What’s the first clue that all living things come from the same ancestor? The answer is written in our genomes. Literally. From ants to blue whales, every cell contains instructions on what to do, when to self-destruct, and how to make another organism. The language that these instructions are written in is the same in all living things. Four nucleotides make up trillions of strands of DNA. By looking for patterns in these nucleotides, scientists can figure out who is more closely related to whom.
Conserved Proteins and Enzymes
Some cell functions are so essential that the proteins and enzymes used in these processes are more or less the same. For example, DNA replication happens in all cells. Enzymes like DNA polymerase are found in all living things. Even giant viruses, such as the mimivirus, have instructions to make polymerase. By looking at how similar our polymerase is with another organism, scientists can figure out how closely related we are.
Phenotype vs. Genotype
When scientists first tried to classify living things, they looked at physical appearances. This is what’s known as phenotype, the physical results of genes. But not all genes have a phenotype; some genes quietly lurk in the background. Darwin’s phylogenetic treeclassified living things into three categories, Bacteria, Archaea, and Eukarya. This tree was also rooted, showing common ancestors. But as technology advanced, humans realized just how little we know, and the art of classifying organisms is continuously changing. This led to the unrooted phylogenetic tree, where only the relationships are shown between organisms.
The Biggest Big Picture
Humans tend to get caught up in all the little details of life. And yes, life is indeed full of petty annoyances. But if you ever want to step back and take in the small role you play on this planet, then all you need to do is study a phylogenetic tree. Our necklaces are a friendly reminder that not only are you not alone on this planet, but distant relatives are everywhere. Purchase one for yourself or make it a gift. It’s perfect for evolutionary biologists, bacteriologists, philosophers, and geneticists.
written by Science with Evie