Which of the following statements about human populations in ind...

Question

Which of the following statements about human populations in industrialized countries is incorrect?
a. Birth rates and death rates are high.
b. Average family size is relatively small.
c. The population has undergone the demographic transition.
d. The survivorship curve is Type I.

Accepted Answer

Welcome back. Here's our next question. What kind of survivorship curve does a human population in an industrialized nation exhibit. And we have our choices of type one, Type two, Type three, or insufficient information to predict. Well, let's recall from our content videos, survivorship is the ratio of individuals of a species that survive at each age as opposed to those that don't. And so a survivorship curve is a graph where we plot the number or proportion of individuals, um sanda the jewels that survive until the following year, over time or over the age of the individual. So I type one curve, I'll do in blue here, looks like this And type one. So that indicates a relatively high rate of survivorship, a low rate of death in early and middle age with a rapid dropping off as we get to old age. So high survivorship in early and middle age with a drop in old age. And this is characteristic of species like humans and monkeys, apes that have relatively few offspring over the course of our lives, and the parents take good care of their offspring, allowing a large number of them to survive and then just dying off of old age. So we can eliminate choice. D because we definitely have enough information, since our types are sort of characteristic of different species. We know we have humans, and even more so we know our human population is in an industrialized nation, industrialized nations generally have relatively good health conditions and that results in relatively low infant and child mortality. So even more. So that confirms that our curve should show high survivorship in early and middle age. So we can say that we expect our correct answer to be Type one for our human population are healthy human population. But let's just be thorough and go through our other types to be sure choice B is Type two. Type do just looks like a straight diagonal line. It's not quite straight there. Here we go. And that is characteristic. That means we have a sort of constant ah rate of survivorship drop over a lifetime. So there's no precipitous time where you have a higher mortality, just the number of them surviving go steadily down regardless of age. There's no specific dangerous time. And that's characteristic of species like songbirds and some lizards. So not applying to our humans. Choice C. is type three and type three I'll do here in black. Type three here involves a rapid drop in survivorship at the beginning of life with this sort of leveling off Once you pass that time. So sort of constant good rate of survivorship once you pass this little bottleneck at the beginning. So type three, you have low survivorship in early age and relatively well not high, but you know, no drops and survivorship. So relatively constant past early age past that bottleneck and this kind of curve is characteristic of species like frogs, fish, other aquatic mammals are animals where they just lay massive numbers of eggs have massive numbers of offspring, tons of them die, get eaten. Other things happen to them, but once they survive that vulnerable early age, you have this relatively good survivorship until, you know, they get too old. So Type three is definitely not our curve for humans here, so we can eliminate that. And we are confirmed. That are correct. Answer is Type One as the survivorship curve for a human population in an industrialized nation. Thanks for watching. See you in the next video.

Watch next