what are some ways that the size of a population can increase or decrease?

Answer 1

increase- high birth rate, low mortality rate, immigration
decrease - low birth rate, high mortality rate, emmigration

Answer 2

yes, increase by the increase of food and nourishment , decease in predators, enough space, and so on for a population boom. it can decrease in a change of enviornment (introduction of an alien/foreign species, climate change) or a natural disaster like an earth quake. a decrease/increase can occur with the actions of humans (usually a decrease and somethimes extinctions)

Answer 3

well it will generally increase if every (or the majority) couple has more than two children- it will decrease because of disease, famine, plagues, epidemics, etc... and of course it will decrease (as I believe it is supposed to for the first time maybe ever) if every couple (again, majority) has less than two children. Especially now where women are so career and money driven, they start families later in life and are limited by time as to how many children then can successfully bare

Answer 4

a population tends to increase when their mortal enemies are eliminated. lately humanity has eliminated so many natural phenomena that we are in excess of seven billion and still snowballing. science is becoming omnipotent and one would think 'that's a good thing"....yeah? well if mother earth were entitled the ability to state an opinion, i'd say she'd beg to differ. we are a dire strain on our own existence, if you will.

now as for reduction of population; war, and disease seem to be the biggest perpetraters in that department. wouldn't you agree?

Answer 5

Wars
Natural disasters
Trojan profalactic company burns to the ground
The "Pill" researchers find it dangerous to use and recall everyone of them.
Stock market crash. serious! People lose their jobs on a large scale and a baby boom results from it.
Chinese government decides not to limit families on births they can have?
Last but not least. Followers of the Lord decide to all convert to being of Catholic religion!

Answer 6

Depends if you mean locally or globally.

Local - Job market can crash - population migrates to other cities
Job market can expand - more people move in

Enivroment becomes poluted - people move out
Enivroment becomes developed - people move in

Global - birth - death
new medical research - extends lives
new chemical posions - deletes lives

Answer 7

way to increase population : allow us mexicans to buy Coronas with our foodstamps.
**but i'm not sure why'd you want that sir.**

way to decrease population : give us mexicans Coronas with secret birthcontrol drug

basically the world's size is in us mexican's hands....

Answer 8

that would be birth and death as the two main ways. Migration, people moving in and people moving out.

Answer 9

births, deaths - naturally
wars, migration (coming in and going out)

Answer 10

the government controlling money is the sole biggest reason,