Bird Beak Lab

Part 1: Analysis
In the bird beak lab, we came to the same conclusion as Darwin did: individuals who have "better" traits, or traits that are more suited to the environment, leave behind more offspring. We simulated 4 different types of birds' beaks with a spoon, a binder clip, a pair of tweezers, and a pair of scissors. The goal was for each bird to pick up as many pieces of "food" (rubber bands, macaroni, toothpicks, paper clips). We saw evidence that individuals with better traits leave more offspring when the tweezers-beaked bird had a total of 18 chicks, the highest among all other birds. A possible explanation for this could be that their beaks were more adept at picking up food. Another of Darwin's conclusions was shown true in our lab: the fact that populations gradually start to look more like the "winners", or individuals with the better traits. The tweezers chicks made up 37% of the population. An explanation for this is that the tweezers chicks collected more food and had more offspring.


Conclusion:
In this lab, we asked the question: if natural selection occurs in a population, how do changes in selective pressures affect the evolution of that species?  We also simulated a drought in this lab, where the drought wiped out all the seed pods (toothpicks). The toothpicks were removed from the birds' supply of food. Theoretically, this would affect only the birds who relied on the seed pods as a source of food. We found an increase in the tweezers chicks' population and the spoon chicks' population, who did not rely on the seed pods as a staple source of food. The scissors chicks' population stayed constant. This data support our claim because the birds did not rely much on the toothpicks for food, therefore the drought did not affect them much.

When we simulated the seed pod drought, our data somewhat contradicted the expected results. We hypothesized that the binder clip chicks' population would increase or stay constant, since it was the only type of bird that had never consumed the seed pods. Instead, the binder clip chicks' population decreased. This was probably due to an error. The binder clip required the user to apply a decent amount of pressure in order to operate it and pick up the food. When doing the back to back trials, using the binder clip became tiring. This error caused the population to decrease, instead of staying the same or increasing. In the lab as a whole, each bird beak was operated by a different student, and each student would have a different skill level in terms of picking up the food. This might have caused certain populations to be too high or too low. Due to these errors, in future experiments I would recommend students switching "bird beaks" in order to make the lab more objective and maybe finding an alternative for the binder clip, because of the finger pressure that is needed to use it.

This lab was done to demonstrate the concept of natural selection, and how every population will have winners and losers. From this lab I learned how natural selection would works in an ecosystem, and I now understand the concept better. Based on my experience from this lab, I can better understand why certain traits are more dominant in certain populations.