Scientists predict that global climate change will cause a greater increase in average temperature at higher latitudes than in the tropics. This seems like good news since most of the world's biodiversity occurs in the tropics. However, recent data suggest that a smaller temperature change in the tropics will cause a larger physiological response in organisms there than the larger temperature change will in organisms in temperate areas. Based on what you have learned about thermal niches in this chapter, propose a hypothesis to explain this result.

Video transcript

Welcome back everyone. Here's our next question. It says the number and variety of living organisms are termed biodiversity. Which of the following factors is responsible for the greatest biodiversity in tropical rainforests. Let's think about tropical rainforests and look through our answer choices. Um We can see that choice A. Says cold temperature low precipitation rate and abundant light. Well um tropical rainforests are warm with lots of rain, so cold temperatures and low precipitation rate do not characterize tropical rainforests and so A. Cannot be our answer choice B says warm temperature, intense light, high precipitation rate and abundant nutrients. These are all characteristics of a tropical rainforest and are all responsible for greatest that great biodiversity. Um When we think about that we know that the warm temperature to the higher temperature and the greater amount of water allow higher rates of metabolism. Um The high amounts of water and light um are gonna allow greater amounts of plants, greater amounts of photosynthesis producing greater amounts of food for all different sorts of animals along the food chain. Both animals that eat the plants and then their predators and the great amount of nutrients also um are part of that greater amount of photosynthesis, greater amount of plants, all providing lots and lots of production for many many different animal species to thrive to co evolve along with each other um allowing many many different organisms in this environment. Um Let's just look at our remaining two answer choices. Choice C says low light and water sorted. Um neither of these characteristic of rainforests so not our answer. And finally choice d Absence of light and excess water well, there's plenty of water, but absence of light would not be characteristic. Tropical rainforests tend to be in the tropics. In those equatorial regions, lots and lots of sunlight available, so Choice D. Not our answer. And which of the following factors responsible for the greatest biodiversity in the tropical rainforest? Choice be warm, temperature, intense, light, high precipitation rate and abundant nutrients. See you in the next video.