Natural Selection and the Evolution of Darwin’s Finches

Another excellent resource from HHMI for teaching evolution and classification: students basically classify 13 of the finch species on the Galapagos and learn about how they came to be how they are along the way.

I’m looking forward to using this in between my evolution and taxonomy units to give students an idea of the thought process scientists go through in classifying a new species, or even a group of new species.

Check it out here.


Yeast Balloon Lab

This is a fun yeast lab that can be used to teach about Fungi in a Taxonomy unit, or to teach about anaerobic respiration in the Cellular Respiration Unit, or just  as a simple introduction to inquiry:

Fungi yeast balloon lab

It focuses on how much CO2 yeast produce in environments with different amounts of sugar in them. My students generally found that the yeast produced the most CO2 for 1mL and 5mL of sugar solution.

To make it inquiry-based:

  • have them first complete this lab, and then ask them the question: what else could affect the rate of yeast CO2 emission?
  • I would suggest leaving the amount of yeast the same, and then changing either the amount of sugar (make the measurements more specific), the amount of sunlight, or the temperature of the water

Thoughts and Tips:

  • students need to know how to make a wet mount slide prior to this lab
  • it’s best if this is done during a lab block (80-ish minutes)–it will take them about 30 minutes to set up, and then they’ll have 40 minutes for data collection
  • pre-heat the water for the yeast to about 90C so that the students can get started with the lab straightaway
  • have the students heat up the water as they’re stirring the sugar in to get more of it to dissolve

From the Students:

“I have never done any labs in my past years in science and it felt like an actual experiment was occurring and it was a very interesting topic”

“It was cool to see something blow up with touching it”