Introduction
Welcome to Topic 7.8 of AP Biology: Continuing Evolution! This article will serve as a quick review of ongoing evolution and how this process takes millions of years.
Continuing Evolution: Genomic Changes & Resistance
Before we continue evolution, we need a recap on what evolution is. Evolution is the change in the genetic makeup of a population over time. Evolution is driven by natural selection and random processes. As Darwin theorised, we all came from one common ancestor, meaning that all life on Earth has evolved to get to where they are and will continue to evolve if needed.
Continuing Evolution: Examples
There are a lot of examples of continuing evolution, but here are some examples of ones covered in the AP Biology course.
- Genomic changes over time are an indicator of evolution.
- Changes in the fossil record also indicate evolution. For example, you’ve likely heard of “homo erectus” or “homo neanderthals,” both of which are closely related to humans. However, their bone structures differ slightly from ours, indicating that we’ve evolved.
- You might wonder why doctors always tell you to finish the entire bottle of prescribed antibiotics, even if you feel better. Let’s say you take half the bottle and feel better, leaving it unfinished. While you may feel better, not all of the virus or illness has been killed off. In fact, the leftover surviving bacteria is stronger and more resistant. The only surviving bacteria reproduce, leading to a population that has a higher percentage of bacteria resistant to antibiotics, and would therefore be harder to eliminate. Ultimately, the bacterial population had evolved to become resistant to antibiotics. If you had simply finished the bottle, all the bacteria would have been killed off, including the stronger ones. Finish your antibiotics.
- Why do you need to get a flu shot every year? For a similar reason, the flu virus evolves, with changes in its RNA and DNA. To address this, doctors administer slightly different flu shots every year to account for these changes.