Many species of animals on islands are larger than related species on the mainland. Scientists hypothesize that this phenomenon, called island gigantism, evolved in response to the scarcity of competitors and predators on islands. Reduced competition and predation allows species to exploit more resources and frees them from the need to hide in small refuges. The graph shown here compares the average carapace (shell) length of mainland and island tortoises. Summarize the results, then use the data to predict whether the surface area to volume ratio is higher in mainland or island tortoises.

Video transcript

Welcome back. Let's look at our next problem. It says the surface area to volume ratio is important to explain the relationship between the structure and function of various processes such as the diffusion of oxygen to cells or blood and heat transfer via conduction. Given the following information on surface area and volume, identify which animal needs to work harder to maintain body warmth. When we think about maintaining body warmth and service arian volume will surface area, It's going to be associated with heat loss. That's because the surface area is where the animal's body will come into contact with the external environment and its heat can be dissipated when we think about volume that's gonna be associated with heat generation, the animal's metabolic processes generating heat within the animal's body. So when we think about hanging on to that heat that's generated inside the body, the animal that will have to work harder will have more surface area oops, compared to volume. And if we're looking at the surface area to volume ratio, we talk about dividing surface area by volume. To get that ratio. So the higher this ratio since greater surface area compared to volume, it makes it harder for the animal to work to maintain its bodily heat. We know that the animal that needs to work harder will have the highest surface area to volume ratio. So let's go ahead and look at our chart where were given four different animals, Elephant camera zebra and seal and were given their surface area and volume. So we'll just ride along. Under here. We'll divide the surface their bible the volume. To get that ratio for elephant 22 divided by 11, we get a ratio of 2-1 For the Camel 13.2 divided by 3.3. It's a ratio of 4 - one. For the zebra 8.1 divided by 2.7. That's a ratio of 3 to 1. And for the seal 2.2 divided by 1.1 is a ratio of 2 to 1. So when we look at for our highest ratio, we see that that's found in the camel At 4-1. So our answer choices. Choice C. Camel. The camel has the highest service area to volume ratio and therefore needs to work the hardest to maintain its body warmth. See you in the next video.