Many people regard the rapid population growth of developing coun...

Question

Many people regard the rapid population growth of developing countries as our most serious environmental problem. Others think that the growth of developed countries, though slower, is actually a greater threat to the environment. What kinds of environmental problems result from population growth in (a) developing countries and (b) developed countries? Which do you think is the greater threat? Why?

Accepted Answer

Hi everyone. Here's our next question. It says which the following can lead to population regulation. Well, let's recall from our content video what that term means and that is those are factors that limit population growth. So we imagine, say, a population of rabbits which as we know, can breed very rapidly produce tons of offspring. But there are factors that will eventually regulate that population. The rabbits will not keep multiplying until they take over the entire world. Um They're going to run into something that causes their population growth to decline. And so let's look at our answer choices for what these factors might be keeping in mind. That choice D. Is all of the above. So there's a chance that all of our answers could be correct choices says competition. While competition for resources can absolutely limit population growth. If our rabbits, for instance, eat up all of the grass in their environment, they will begin to die off from lack of food. So I'm just going to markets correct. Since we have the all of the above choice. But that's definitely something that can be a factor choice. B. Is diseases, diseases also are things that can limit population growth. The disease begins to spread among the population and cause individuals to die off before they can reproduce. That will limit population growth. At this point, I can go ahead and say that my answer choice must be the all of the above, since I've already got more than one correct answer but to be thorough here, we'll look at Joyce see which is wild fires and wildfires definitely can limit population. Wildfire come through can actually kill individuals. It also could destroy their habitat um leading them to die off or decline in population. Um It is good to note here as we look to these factors, that factors in population regulation kind of come in two varieties or flavors, I'll just put them up here and those are density dependent factors and density independent factors, density dependent factors affect the per capita growth rate differently depending on how dense the population is. Um So and these tend to be biotic factors having to do with living organisms and their interactions. So in our example here competition and diseases are density dependent. Competition for resources will have a greater effect on the per capita growth rate. The more dense the population is because you have more individuals in a smaller space competing for the resources in that area. As individuals die off, there's a less dense population, there's less competition for those resources. So there'll be less effect on the growth rate, diseases also density dependent as disease will spread more quickly in a very closely packed population. Whereas as individuals die off spread out, there will be less chance for disease to spread. The other is density independent. Um These affect the per capita growth rate regardless of how dense the population is. Um And an example, the example here is a wildfire doesn't matter if there's a ton of money is in an area or very few Um wildfire will is going to affect that population um, regardless. And these tend to involve the physical environment like a wildfire or we can think of the dinosaurs and the asteroid doesn't matter how dense the dinosaur population is. Um, the asteroid will affect them. And another note I put here is they don't have corrections. And that means as we discuss the density dependent factors as the population growth declines due to this, whatever this factor is, you will see that factor affect them less and the population can rebound. So disease spreads through a dense population individuals die off that population is less dense, more spread out. The disease will kind of come to a halt as it can't spread so easily anymore. Whereas density independent factors don't have these corrections since it doesn't matter how few individuals you have, they can still be affected by that wildfire by that asteroid. And so density independent factors can kill off an entire population in some cases. So just a little note about those two types of population regulation, but again, which the following can lead to population regulation and the answer is choice. The all of the above see you in the next video

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