Question

ANT 301 Introduction to Biological Anthropology Summer 2020 size and body shape alone may have had something to do with how quickly an organism loses/gains heat. In this part of the lab, you will model the body shapes of modern humans and Neanderthals as simple cylinders. The femur length and bi-iliac breadth of the Neanderthal and the modern human have been measured and entered into the chart below. Use the instructions below to calculate the height and radius of the cylinders (4 pts). Femur Bi-iliac length width (cm) (cm) Stature or cylinder height=femur length 4 Cylinder radius-bi-iliac width X.5 Neanderthal 42 30 height (h) cm radius (6) cm Homo sapiens 37 22.5 height (h) = cm radius () = cm Now that we have the height and radius of each cylinder we are able to calculate the surface area and volume of each cylinder (answers provided below). Calculate the surface area to volume ratio for each hominoid (2 pts). Neandertal: Modern human: SA 17247 cm? VOL 119000 cm SA/VOL = SA 11256 cm ? VOL 58846 cm SA/VOL = What can you infer about climate and Neanderthal evolution through this comparison? (1 pt). a) Neanderthals are adapted to live in warm climates because they have a lower SA/VOL ratio. b) Neanderthals are adapted to live in cold climates because they have a higher SA/VOL ratio. c) Homo sapiens are adapted to live in cold climates because they have a lower SA/VOL ratio. d) Neanderthals are adapted to live in cold climates because they have a lower SA/VOL ratio.

Answer 1

The size and body shape play an important part with respect to how quickly an organism loses or gains heat. Here the body shapes of modern humans and Neanderthals are considered as simple cylinders. The femur length and bi-iliac breadth of the Neanderthal and modern human have been measured and given as below:

	Femur length (cm)	Bi-iliac width (cm)	Stature or cylider height= femur length $\times$ 4	Cylinder radius= bi-iliac width $\times$ 5
Neandertal	42	30	height (h)=$42\times 4=168$ cm	radius (r)= 30 x 5 = 150 cm
Homo sapiens	37	22.5	height (h)=$37\times 4=148$ cm	radius (r)= 22.5 X 5 = 112.5 cm

Now the surface area and volume of each cylinder are given. The surface area and volume for each of Neandertals and Modern humans are as follows:

Neandertal: SA: 17247 cm²; VOL: 119000 cm³; SA/VOL=$\frac{17247}{119000}=0.144$

Modern human: SA: 11256 cm²; VOL: 58846 cm³; SA/VOL=$\frac{11256}{58846}=0.191$

From the following observation and comparison of the SA/VOL ratio of modern human and Neanderthals, it is clearly evident that Neanderthals are adapted to live in cold climates because they have a lower SA/VOL ratio.

Animals generate internal heat in proportion to their volume, this means that larger the volume of the animal, the more heat it can produce. Now the Neanderthals have a greater volume as compared to modern humans, so they cn able to generate more heat. The proportion of heat loss externally is directly related with surface area, this means that the larger the surface area of the animal, the more it can lose. But the comparative analysis of SA/VOL ratio indicates that Neanderthals had a lower SA/VOL ratio than modern humans. This suggest that, less heat is lost relative to its volume. So they are better adapted to cold climates.

Option (d) is the correct answer.