Diversity of Life

Life on earth is made up from many different species. So many that we do not even know of them all. From the smallest single organism cell to Homo sapiens, we are all composed of small building blocks. 2000 years ago Aristotle created Taxonomy, a way to classify plants and animals to help us understand the many different species on earth and where Homo sapiens fit into this concept.

There are one and a half million species on the earth, some currently living but most already extinct and many more not even classified nor even found yet. The fist attempt to classify each species was by Aristotle 2000 years ago. His classification started with Kingdoms. He split everything up in two classifications: Plants and Animals, then in to three sub categories, water, land and air. Plants were grouped by their stems. This was a good start but Carl Linnaeus created more extensive classifications by morphological features (DNA structures). DNA structures connect all living things. Linnaeus created five kingdoms: Plants are autotrophs that produce oxygen. Animals are multi celled, heterotrophic, move voluntarily and breathe oxygen. Fungi are saprophytes that feed off other sources like athletes foot fungus. Monera are split in half between bacteria like what you have on your hands or in your stomach. Archaea are cells that feed off of salty and acidic substances like what you would find on mars and Protista, which have a true nucleus like an amoeba. We Homo sapiens fall into the animal kingdom (Greunke, 2009).

Living things are composed from cells. Cells increase in size, number or both. Some continue to grow their whole existence and some have an adult size where they stop growing. Living things are able to reproduce, respond to stimuli, and move when they interact with the environment. Evolution shows that living things can evolve over time to better adapt to changes, providing those changes do not wipe out a species. Humans are the best example of how a living thing can grow, change, reproduce and evolve (Greunke, 2009). The biggest issues the world faces now is the fact that humans have evolved and reproduced to the point of excessive