Bird Beak Lab

1. Graphs

2.  Part 1 Analysis

Individuals with better traits leave more offspring. The evidence for this is that in part 1 graph the tweezer beak had the highest number of chicks, eventually making up 39% of chicks. This is because the tweezer beak was able to collect more food. If they able to collect more food then there would be more offspring.

Populations begin to look more like the winners. The evidence for this is that the tweezer chicks  can collect more food, therefore, the offspring will survive. They “win” by getting food is competitive in nature. If more of the offspring survive, then the population of chicks will look like the tweezer chicks.

3. Part 2 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 found that the organisms, in this lab birds, with better traits that allow them to get more food survive and leave more offspring. In our lab the chicks that were able to get more food, the tweezers chicks and the scissors chicks, made up a larger percentage of chicks (39% , and 27% respectively) . In part 2, when faced with the avian flu,  the tweezers and the scissors have the highest amount of offspring because they were able to collect more food. This relates to Darwin’s principle as his conclusion was that the organisms with the highest fitness would survive and pass on their genes to their offspring, leading to evolution of the species for organisms with the best traits.

While our data supported the hypothesis, the possible errors could have been due to the hands of students being tired or some students being quicker than others. This would lead to a disadvantage/advantage of getting food, this would alter the results because it's not based on the beak shape. Instead of using our hands, the lab would be improved by using a more uniform motion, like using shovels with different shapes. Also I would recommend that one student try out all of the different beaks instead of making different students using different beaks.

This lab was done to demonstrate the effects of selective pressure on the evolution of a species. From this lab I learned that the organism that has the best trait for the environment will have more offspring and pass on their genes, especially when faced with selective pressures that cause competition. This helps me understand the concepts of evolution and natural selection and how competition plays a role. Based on my experience from this lab, I can also think about how animals today have evolved in the world today and what traits make them best adapted, especially in environments heavily affected by humans.