Darwin’s Finches: The Right “Beak” for Evolution

Purpose:

To use various tools as analogies of finch beaks found on finches on the Galapagos Islands

Background:

The problem is, can analogies be used to provide an understanding of evolution? Darwin's finches are an excellent example of the way in which species' gene pools have adapted in order for long term survival via their offspring. The Darwin's Finches diagram below illustrates the way the finch has adapted to take advantage of feeding in different ecological niche's.

Their beaks have evolved over time to be best suited to their function. For example, the finches who eat grubs have a thin extended beak to poke into holes in the ground and extract the grubs. Finches who eat buds and fruit would be less successful at doing this, while their claw like beaks can grind down their food and thus give them a selective advantage in circumstances where buds are the only real food source for finches. The hypothesis will be if various tools representing finch beaks are used to simulate adapt- ability, then variations due to niches, survival, and competition will be made evident as an explanation for evolution.

“Small Seed Island”

Procedure:

1. Gather all necessary materials for the activity when directed.
2. Gather in groups of 4-5 and randomly assign each other a number between 1-5. Note: … evolution is random based actually on what genes the offspring receive from their parent; thus, that is the reason why you randomly need to assign each other a number. The “beaks”, which have been assigned a number prior to the lab, will then be given to you (the student, “finch”)
3. The simulation will include 2 rounds and is to address the following question, “How does a certain beak shape affect the competitiveness of a finch?” Also, the number of seeds collected is to measure “survival” of that particular finch. Keep in mind that competition “and” the availability of niches are important factors in defining different species; such as, with the finches on the Galapagos islands.
4. Answer the questions on the data sheet after each simulation.

Students finding out if they are successful on a “Small Seed Island” with the tools that they were randomly given.

Later they would “compete” for food on the “Small Seed Island” and the “Large Seed Island”

- some were surprised by the results -