Brain/Body size

The dataset below contains data by species. Brain Weight is in grams, Body Weight is in kilograms. Data from "Data Analysis, an Introduction", by Jeff Witmer.


"Brains" <-
structure(list(Species = structure(c(7, 11, 12, 19, 24, 25, 26, 
34, 37, 8, 3, 20, 30, 6, 36, 23, 15, 9, 18, 28, 32, 35, 39, 14, 
31, 38, 27, 5, 4, 21, 2, 13, 10, 17, 22, 33, 29, 1, 16), .Label = c("African.elephant", 
"baboon", "barracuda", "bat", "blue.whale", "brown.trout", "canary", 
"catfish", "cheetah", "chimpanzee", "crow", "flamingo", "grey.monkey", 
"greyhound", "grizzly.bear", "horse", "human", "lion", "loon", 
"mackerel", "mole", "mouse", "northern.trout", "ostrich", "pheasant", 
"pigeon", "porpoise", "raccoon", "rhinoceros", "salmon", "seal", 
"skunk", "squirrel", "stork", "tiger", "tuna", "vulture", "walrus", 
"wolf"), class = "factor"), Brain = c(0.848, 9.3, 8.05, 6.12, 
42.11, 3.289, 2.694, 16.24, 19.6, 1.84, 3.83, 0.64, 1.257, 0.57, 
3.09, 1.233, 233.9, 2.449, 106.7, 40, 10.3, 302, 152, 105.9, 
442, 1126, 1735, 6800, 0.936, 1.16, 140, 66.6, 440, 1377, 0.551, 
3.97, 655, 5712, 618), Body = c(0.0171, 0.337, 1.598, 1.53, 
123, 0.625, 0.282, 3.35, 5.27, 2.894, 5.978, 0.765, 3.93, 0.292, 
5.21, 2.5, 142.88, 22.2, 28.79, 5.175, 1.7, 209, 29.94, 24.49, 
107.3, 667, 142.43, 58059, 0.028, 0.0396, 7.9, 4.55, 56.69, 74, 
0.0177, 0.183, 763, 6654, 461.76), Class = structure(c(1, 1, 
1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3), .Label = c("bird", 
"fish", "mammal"), class = "factor")), .Names = c("Species", 
"Brain.WT", "Body.WT", "Class"), row.names = c("1", "2", "3", 
"4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", 
"16", "17", "18", "19", "20", "21", "22", "23", "24", "25", "26", 
"27", "28", "29", "30", "31", "32", "33", "34", "35", "36", "37", 
"38", "39"), class = "data.frame")