Exercise 65

Different varieties of the bright tropical flower Heliconia are fertilized by different species of hummingbirds. Over time, the lengths of the flowers and the form of the hummingbirds’ beaks have evolved to match each other. Below are data on the lengths in millimeters of two varieties of these flowers on the island of Dominica. Exercises 65-69 use these data.

238

Heliconia caribaea Red
37.40	38.07	38.87	40.66	41.93
37.78	38.10	39.16	41.47	42.01
37.87	38.20	39.63	41.69	42.18
37.97	38.23	39.78	41.90	43.09
38.01	38.79	40.57
Heliconia caribaea Yellow
34.57	35.45	36.03	36.66	37.02
34.63	35.68	36.11	36.78	37.10
35.17	36.03	36.52	36.82	38.13

Table 5.46: Thanks to Ethan J. Temeles of Amherst College for providing the data. His work is described in Ethan J. Temeles and W. John Kress, Adaptation in a plant-hummingbird association, Science, 300 (2003): 630-633.

Question 5.95

65. Make stemplots of the lengths of each of the two varieties (red and yellow). Briefly describe the overall shape of the two distributions.

65.

As can be seen from the following stemplots, lengths of red flowers are somewhat right skewed with no outliers; lengths of yellow flowers are reasonably symmetric, also with no outliers. For the stemplots, values are rounded to the nearest tenth.

A13