The Beaks of Finches NYSED Lab

What is the “goal” of the lab? Demonstrate how Darwin’s Finches (those that he observed on the Galapagos Islands) have adapted new beaks yet remain similar to the shared common ancestor that most likely came from the mainland.

Required Supplies for “B of F” A randomly assigned “beak” Small seed island Petri dish Large seed island Timer

Round 1 Only one seed at a time may be eaten. To be “eaten” it must land inside your stomach. If you scoop seeds or eat more than one at a time, you “choke” and vomit all of your seeds out. Average is taken from four trials, 60 seconds each.

And now, Round 1… Did you average over 13 seeds? YES NO Seeds Collected Partner #1 Trial #1 Trial #2 Partner #2 Trial #3 Trial #4 Average Did you average over 13 seeds? YES NO Go to Round 2 Increased Competition Repeat Round 1 on the “big seed” island with the same beak

Successful in Round 1? Welcome to Round 2!!! Repeat the same procedure but this time have another “bird” to compete against! Round 2 - Increased Competition Seeds Collected Partner #1 Trial #1 Trial #2 Partner #2 Trial #3 Trial #4 Average Complete the table and move on to Round 3 where there is “Increased Competition” if you average over 13 seeds.

Unsuccessful in Round 1? Did you average over 13 seeds this time? YES Go to a “large seed” island and start over (even though you have starved to death, you are resurrected) Seeds Collected Partner #1 Trial #1 Trial #2 Partner #2 Trial #3 Trial #4 Average Did you average over 13 seeds this time? YES NO Get a new “beak” and try yet again (not a possibility in nature) Go to Round 2, but with another large seed eater as competition on the “large seed” island

Successful in Round 2? Welcome to Round 3!! Increased Competition (more than 1 other bird) Repeat the same procedure but this time have even more birds to compete against! Seeds Collected Partner #1 Trial #1 Trial #2 Partner #2 Trial #3 Trial #4 Average Don’t fret. It is almost over!

Not successful in Round 2? “Here endeth the lesson…”

So, what did you learn? Birds have evolved many different mechanisms and modifications that make them more well-adapted to the environment in which they live. Structural differences (in beaks) are significant enough to make you into a new species, but you did descend from a common ancestor. The adaptations that contribute to the most success allow that individual to survive and reproduce. The adaptations that are contribute to a lack of success are not passed on since they either starve or have no “breeding rights”.

Questions: The diagram above shows variations in beak sizes and shapes for several birds on the Galapagos Islands. Using information provided in the chart, identify two birds that would most likely compete for food in times of food shortage and explain why they would compete.

2. Even though the finches on the various Galapagos Islands require different biotic and abiotic factors for their survival, these finches would most likely be grouped in the same (1) species, but found in different habitats (2) kingdom, but found in different ecological niches (3) species and found in the same biosphere (4) population, but found in different ecosystems

3. Galapagos finches evolved partly due to (1) cloning and recombination (2) migration and selective breeding (3) mutation and asexual reproduction (4) variation and competition

4. In members of a bird species living on a remote island, the greatest number of beak variations in the population would most likely be found when (1) there is a high level of competition for limited resources (2) homeostasis is limited by a severe climate (3) they have a large and varied food supply (4) they are prey for a large number of predators

5. The different tools used during the beaks of finches lab represented (1) feeding adaptations in finches (2) nest construction adaptations (3) variations in seed size (4) variations in ecosystems