1.5 Percent

What makes us human? A question society still searches an answer for. People find ways to come up with philosophical or abstract answers: our souls, our emotions, our creativity. In English class we watched a video of a gorilla supposedly communicating its life story through sign language and a girl who grew up in isolation who couldn't talk, along with an excerpt of Wall-E. People then argued for which one they thought was the most "human." After all, the gorilla conveyed communication, Wall-E showed curiosity and emotion, while the girl was at least born human. But this seems like the completely incorrect path to take to find the answer to what makes us human. This path leads to discussions with no evidence or data but simply people arguing their own opinions. If we really want to know what makes us human, lets turn to science.

Now, before I move on, I will establish a fundamental definition we must accept: that "human" equals "homo sapiens." Let me defend why this equality holds. Everything that defines us as a species, makes us human. If something not biological makes us human, than that implies some otherworldly thing exists in us. Religion builds off that assumption, that within man lives the image of God. Or some other invisible thing lies within only humans that we coincidentally can't see or even understand. I personally find that difficult to believe, especially when all living organisms have the same basic nucleotides that create DNA. Humans are made of atoms, just like everything else in the world except black holes and dark matter. So lets assume homo sapiens do not have some otherworldly thing that magically give us "human only" qualities (whatever qualities those are).

According to science, there is a 1.5% difference in human DNA than chimpanzees, which could mean up to 45 million DNA sequence mutations. It's important to remember that humans are a product of evolution. We did not magically appear and there is probably no one magical explanation for what makes us human. It's the accumulation of those 45 million DNA sequence mutations that make us human, unless that especially special invisible human "thing" exists. So here are some concrete differences. According to scientists, one major mutation is in the MYH16 gene, a distinctly human mutation, which allows the brain to be larger by having weaker jaw muscles. A larger brain may have also been influenced by humans brain to use complex tools such as the Achuelean hand axe. According to scientist Dietrich Stout, learning to use stone tools (a.k.a. learning about nature/exploring environment resources) may have allowed the brain to develop the capacity to create language. Another gene mutation plays a part in language, the FOXP2 gene (this gene underwent a mutation around the time humans are believed to have developed language). This gene mutation may have allowed humans to communicate language better. Scientists are still searching for the complete answer to what makes us human, but clearly we know there are fundamental biological differences that account for any human qualities we see.

Achuelean Hand Axe

The reason it's important to look to science when we discuss humanity is because humans seem to forget that we are biologically part of nature. We are made up of atoms and DNA just like everything else. Nature shapes who we are through DNA mutations that lead to our ability to use tools, create languages, and invent. If we take out the biological differences or dismiss them, then that means something makes us human that is not part of nature. Which would mean we are not part of nature, but science says otherwise. Nature is what created humans, through DNA mutations, natural selection, and different environments. Sure humans can try and manipulate nature through technology but the reasons humans do is because of how nature shaped us. So what makes us human? A 1.5% difference in our DNA sequence.

Further explanation of the gene mutations: http://genetics.thetech.org/original_news/news8
Interesting Nova episode exploring what makes us human: http://www.pbs.org/wgbh/nova/evolution/what-makes-us-human-pro.html