Which of the following was the average beak size of the finches on the island of Daphne Major in 1976?

Asked by lucylu242

Discuss which characteristic you anticipate will be most significant in allowing the finches to survive in the new dry environment.

Your answer:

In the Summers of 1976 and 1978, on the island of Daphne Major, Peter and Rosemary Grant collected as many birds as the could, in both 1976 before a drought hit and in 1978 after a severe drought.

They measured the beak size of each medium ground finch, and tallied up how many birds of each had beaks that size. E.g. in 1976 one bird had a 7.5 mm beak depth, while the same year, 3 birds had a 10.25 mm beak depth.

Two graphs show the beak depths (in mm) of the finches that did not survive the drought, and of the finches that did survive the drought on the island of Daphne Major.

Image transcription text

Beak Depths of 50 Medium Ground Finches That Did Not Survive the Drought LO Non-survivors - - Mean = 9.11 mm Standard Deviation (s) = 0.88 Number of Birds W 10.25 10.5 10.7 11.25 18.5 11.75 Beak Depth (mm) Beak Depths of 50 Medium Ground Finches That Survived the Drought 10 Survivors = =Mean = 9.67 mm Standard Deviation (s) = 0.84 7 Number of Birds 6 5 7.75 8.75 10.25 10.5 10.78 1 1 11.25 11.5 11.75 Beak Depth (mm)

Compare the two graphs of the beaks of the finches that did and did not survive the drought

What trend can you observe about average beak depth?

Your answer:

The next two graphs show the beak depths (in mm) of the offspring in 1976 and 1978, a total of 100 medium ground finches, on the island of

Daphne Major, before and after the drought.

Make some observations about the trend of the two graphs by considering these questions.

• Tell what factor is counted each year. 
• Which two beak sizes were most abundant in the birds before the drought?
• Which beak size was most abundant in the offspring of birds that did survive the drought?

Use your observations, together with the two graphs, to make a comparison about the average beak size for the population of medium ground finches before and after the drought.

Your answers:

Peter and Rosemary Grant recorded data from over 1000 different finches. However, the graphs show data regarding only 100 individuals of a population. Suggest some the advantages and disadvantages of using this data set.

Your answer:

After the drought another set of data showed that the surviving finches had slightly longer wings and slightly larger bodies. Yet, Peter and Rosemary Grant stated that the trait that made the difference for the survival of the population was beak depth. Explain this statement.

Your answer:

After analyzing data compare it to your expectation? 

Your answer:

In 1983, it rained ten times more than normal. The island was overrun by vines that covered even the cactus. This changed vegetation caused the larger seeds became scarce. 

In this scenario, predict which beak shape will have an advantage for finches to eat and, therefore, to survive and reproduce?

Your answer:

Make a prediction about the average beak size in the population of medium ground finch in the year immediately after a very rainy year, compared to the years right after the drought occurred.

Your answer: