Answer:
Earth might be a bit like Mars, with a very thin atmosphere and no more volcanoes or earthquakes. Then it would be very difficult for life to survive.
Explanation:
The correct answer is Birth.
The two elements that raise population size are natality—the number of people who are added to a population over time as a result of reproduction—and immigration—the movement of people into a location. Most births are to folks who are young adults or older. Even at replacement fertility levels (when each woman has approximately an average of two children), there will be more births than deaths if the proportion of young adults to older adults is higher where mortality is highest. Immigration and birth rates lead to population growth. The population shrinks as a result of death rates and emigration. A population that has a negative growth rate is one in which there are more deaths and emigrants than births.
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brainly.com/question/21290161
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<span> The amount of </span>energy<span> at each </span>trophic level<span> decreases as it moves through an ecosystem. </span>
