The Stuff of Life

One of the oldest questions in biology is the origin of life on Earth. Over the years there have been many different hypothesis, but a general consensus is hard to come by. As a scientific community, we have figured out that the earliest replicating molecules were RNA. RNA is made of Uracil, cytosine, adenine, and guanine, which are all nucleic acids. Researcher Thomas Carell now claims that he has found the chemical reactions that would give rise to all four of these molecules. He has created these molecules using the basic elements present on an early earth: oxygen, nitrogen, methane, ammonia, water, and hydrogen cyanide. The only missing part of the chemical equation that Carell has not figured out is how to activate the four “building block” molecules to start linking up and replicate. But this is a major step, figuring out how they were created.

This information works well in a biology classroom because this process began the entire process of biological evolution. The entire spectrum of bio-diverse organisms that we see on earth today all came from these couple reactions. Knowing what the building blocks are and how they were created allows students to try and fill in the missing information. What phenomenon could have kick started RNA replication? How could RNA have evolved into DNA? An advanced high school biology or chemistry class could even take a dive into the chemical reaction that produced adenine, cytosine, guanine, and uracil from basic elements. This is very dense material, so I would have high school students use the close reading method when they are tackling this. It will require a lot of thinking and digesting so it fits well into the idea that thinking underlies reading.

Incorporated Standard: (5-PS1–4) Conduct an investigation to determine whether the mixing of two or more substances results in new substances.

(HS-LS1–1) Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins which carry out the essential functions of life through systems of specialized cells.

https://www.sciencemag.org/news/2016/05/rna-world-inches-closer-explaining-origins-life