Sixty-five million years ago the dinosaurs went extinct. Extinction of species on Earth is a normal phenomenon. As some species evolve, others die out. When discussing extinction, it’s important to know the difference between an extinction and a mass extinction. There have been five big mass extinctions since the beginning of Earth.
1. Ordovician
2. Devonian
3. Permian- most dramatic
4. Triassic
5. Cretaceous- most famous (dinosaurs)
So, what makes these 5 “mass extinctions?” Mass extinctions occur when hundreds of species are going extinct; not just a few. Within the conservation biology field, we refer to the “background extinction rate” to determine whether extinctions that are occurring are considered mass extinctions. The background extinction rate (normal/sustainable) is 1-10 species going extinct annually. Mass extinctions are when the rate significantly exceeds these numbers. The 5 mass extinctions listed above were filed under this term because of the sudden loss of hundreds of species. Today, we are losing species at a rate 100-1000 times the background extinction rate, which makes us literally living in the 6th mass extinction. Let that sink in.
Hundreds of species are going extinct so fast and most people don’t even know that the 6th mass extinction is literally occurring every day as you go to work, school, and run errands. You know what’s even more sad? Unlike the other 5 mass extinctions, this one is caused by humans.
There are many factors as to why species go extinct. Here are the top ones:
1. Habitat Loss
a. Habitat degradation
b. Habitat fragmentation
2. Invasive Species
3. Over Exploitation
4. Disease
5. Climate Change
a. Intensified extreme events (tropical storms, wildfires)
b. Rising sea levels
6. Pollution
a. Air pollution
b. Water pollution
c. Light pollution
d. Noise pollution
7. Intrinsic factors (determined by species)
a. population size
b. habitat preferences
c. reproduction
d. genetics
How to decrease extinction effects by addressing the above factors:
1. Habitat Loss
a. Don’t destroy habitats (logging, burning, etc.). Do so sustainably.
b. Don’t support companies that contribute to logging and deforestation (ex: don’t support companies that wipe out a huge habitat just to expand their company).
2. Invasive species
a. Become educated on what species near you are considered invasive
b. Follow rules set by conservationists in preventing transfer of species (ex: zebra mussels)
3. Over Exploitation
a. Know what’s sustainable and what’s not
b. Don’t support or engage in the hunting of endangered species (ex: hunting safaris in various African countries)
4. Disease
a. Donate/support zoos and other wildlife health organizations that focus on disease transfer
5. Climate Change
a. Limit your carbon emissions
i. Eat less meat
ii. Support eco-conscious companies (even if it may be more expensive)
iii. Take advantage of renewable energy
iv. Carpool
v. Use city-busses instead of your own car
vi. Limit over-consumption
b. Support climate activists in governmental roles
i. Voting
ii. Promoting politicians in an educational way
iii. Join environmental/conservation organizations
c. Become educated on what climate change is, why it is occurring, and how it is causing species extinctions
i. Read scientific peer-reviewed articles
ii. Don’t believe everything you see on social media or hear on the news. Media targets specific audiences that are biased.
iii. Ask questions if you don’t understand. Don’t assume things.
d. Be an active member of a scientific field
i. Study environmental science, environmental policy, sustainability, climatology, geology, conservation biology, ecology, zoology, etc...
6. Pollution
a. Take advantage of renewable energy
b. Limit usage of products that emit unnecessary greenhouse gases
c. Don’t support companies that are big polluters
i. Oil industries avoid with electric transportation
ii. Factories buy from local small companies
iii. Online delivery services; be careful how much you order packages online and. have food delivered (this is increasing the need for frequent transportation, which isn’t always sustainable)
d. Turn lights off when not in use
e. Engage in petitions that urge stores to turn off all (or at least reduce) the lights when closed
f. Support anti-pollution companies
i. Example: 4Ocean
g. Limit Plastic waste
i. Limit single use plastics
ii. Straws, lids, cups, condiment cups, plastic bags, plastic silverware, etc...
For more information about the 6th Mass Extinction, check out this book by Elizabeth Kolbert
References
BioInteractive, hhmi. (n.d.). Retrieved from https://www.biointeractive.org/classroom-resources/seed-dispersal-and-habitat-fragmentation
Brickman, J. (n.d.). Learning the Causes of Extinction. Retrieved from https://www.scholastic.com/teachers/lesson-plans/teaching-content/learning-causes-extinction/
Cherwin, K 2019, Zoology 360: Extinction of Species, lecture notes, University of Wisconsin- Madison, delivered fall semester 2019.
Department of , C. H. and the G. (2019). Retrieved from https://www.chg.gov.ie/heritage/climate-change/