Microevolution consists of small-scale changes in a
population over a shorter period of time. These changes are observed in one or
a few genes and can lead to phenotypes responsible for the survival of the
population. Examples of microevolution can be seen in the appearance of
drug-resistant bacteria and pesticide-resistant insects. These resistances are
derived from the characteristic large population and short lifecycles of the
species.
Here’s how it works. Let’s take a look at drug-resistant bacteria.
Within a population, there are some bacteria that had genetic modifications on
one or a few genes that resulted in their resistance to antibiotics. When the
population is exposed to antibiotics, the normal bacteria die while the
resistant kind survives and reproduces. Eventually, the entire population is
composed of drug-resistant bacteria, which spreads into new settings.
As bacteria are exposed to different antibiotics, resistance to such may emerge and create superbugs (which are resistant to multiple antibiotics). This shows the importance of being treated with antibiotics as directed and only when needed, as well as washing and sanitizing your hands frequently, and handling food properly.
References:
Evidence for evolution (article). (n.d.). Retrieved February 03, 2021, from https://www.khanacademy.org/science/biology/her/evolution-and-natural-selection/a/lines-of-evidence-for-evolution
Examples of microevolution. (n.d.). Retrieved February 03, 2021, from https://evolution.berkeley.edu/evolibrary/article/side_0_0/microexamples_01#:~:text=Pesticide%20resistance%2C%20herbicide%20resistance%2C%20and,to%20several%20kinds%20of%20antibiotics.
How antibiotic resistance happens. (2020, February 10). Retrieved February 03, 2021, from https://www.cdc.gov/drugresistance/about/how-resistance-happens.html
Resisting our drugs. (n.d.). Retrieved February 03, 2021, from https://evolution.berkeley.edu/evolibrary/article/0_0_0/bergstrom_03
Protect yourself from superbugs. (2020, March 20). Retrieved February 03, 2021, from https://www.mayoclinic.org/diseases-conditions/infectious-diseases/expert-answers/superbugs/faq-20129283
Great info! Do you think we'll ever come up with a way of combating bacteria without them eventually growing resistant to our methods? I heard somewhere that brass is a natural killer for microbes, but I don't know how it compares to modern chemicals, or if they can become resistant to it. Thoughts?
ReplyDeleteHi Victoria,
ReplyDeleteI've learned about this a few times but I've never seen such a great description that wasn't filled with unnecessary info that also had a simple, easy to understand picture. You really made the whole concept of antibiotic resistance click in my mind so thank you! One question I had while reading this was: How did the antibiotic resistance first occur in those original few genes? Was it just by chance that the correct genes that the bacteria needed to survive just so happened to be mutated, or did something else cause the mutations?