I investigate the finch’s beak. Beak size is a trait that affects survival. Birds with small beaks are more efficient at utilizing small soft seeds whereas birds with large beaks are better at utilizing large hard seeds. Therefore, when more small seeds available, birds with small beaks would have a higher rate of survival than birds with large beaks. Via versa, when larger seeds available, birds with large beaks would live longer than birds with small beaks.
The experiments I did to see how the beak size and the bird population evolve over 300 years between Darwin Island and Wallace Island by changing some of the inputs suggested in the assignment. Four experiments were done using variance, heritability, beak size traits, and variable precipitation. Wallace Island is the control and Darwin Island is my treatment. The figures 1, 2, 3, and 4 are summaries of the inputs used in the experiments.
Figure 1 Input SummaryFigure 2 Input Summary
Figure 3 input summaryFigure 4 input summary
Figure 1 Result: By increased the beak size to 24 mm, increased the variance of the beak trait to 2.0, and reduced the precipitation to 0 on the Darwin Island to get all 100% hard larger seeds, I expect the Darwin finch’s beak two times larger than the finch’s on beak as on the Wallace Island and should have higher survival rates. Based on the regression lines, the birds’ beak size on the Darwin Island were twice larger then the Wallace Island and were able to adapt to hard larger seeds and increased the population in the rate set the variance trait.
Figure 2 Result: I decreased the beak size to 10 mm and reduced the variance of the trait to 1 as well as increased the precipitation to .82 to have more small soft seeds available on Darwin Island. I expected the birds at Darwin Island to adapt the new environment and increased the population over time. The experiment showed result that the birds with smaller beak size survive at higher rate than the Wallace Island and also increased its population.
Figure 3 Result: In the 3rd experiment, I changed the beak size on the control island to 30mm, reduced variance of trait. I also changed the precipitation of the environment too 100 to ensure there is no large hard seeds available. My expectation was that the birds would have a hard time adapting the new environment and therefore, its survival rate would be very low. As proven through the graphs shown above, on Darwin Island, the birds beak size was too small and were not able to eat large hard seeds and the birds died quickly and seemed almost went extinct.
Figure 4 Result: The last experiment, I reduced the birds’ beak size to 10mm, increased the heritability to 1 as well as variance of the trait to 1.50 and reduced precipitation to 0. I expected the birds evolved over times and able to adapt the new environment since there were smaller soft seeds available. The result showed the finch’s population increased and survival rates were higher than the Wallace Island
Figure 1 Result: By increased the beak size to 24 mm, increased the variance of the beak trait to 2.0, and reduced the precipitation to 0 on the Darwin Island to get all 100% hard larger seeds, I expect the Darwin finch’s beak two times larger than the finch’s on beak as on the Wallace Island and should have higher survival rates. Based on the regression lines, the birds’ beak size on the Darwin Island were twice larger then the Wallace Island and were able to adapt to hard larger seeds and increased the population in the rate set the variance trait.
Figure 2 Result: I decreased the beak size to 10 mm and reduced the variance of the trait to 1 as well as increased the precipitation to .82 to have more small soft seeds available on Darwin Island. I expected the birds at Darwin Island to adapt the new environment and increased the population over time. The experiment showed result that the birds with smaller beak size survive at higher rate than the Wallace Island and also increased its population.
Figure 3 Result: In the 3rd experiment, I changed the beak size on the control island to 30mm, reduced variance of trait. I also changed the precipitation of the environment too 100 to ensure there is no large hard
seeds available. My expectation was that the birds would have a hard time adapting the new environment and therefore, its survival rate would be very low. As proven through the graphs shown above, on Darwin Island, the birds beak size was too small and were not able to eat large hard seeds and the birds died quickly and seemed almost went extinct.
Figure 4 Result: The last experiment, I reduced the birds’ beak size to 10mm, increased the heritability to 1 as well as variance of the trait to 1.50 and reduced precipitation to 0. I expected the birds evolved over times and able to adapt the new environment since there were smaller soft seeds available. The result showed the finch’s population increased and survival rates were higher than the Wallace Island
