Overpopulation is already a problem. And I've talked about it a lot with friends and family.
Here's the thing though. A lot of scientists believes we'd reach overpopulation by the year 2000. However, they failed to take in to consideration agricultural research etc. Now we genetically manipulate harvests and animals in to producing more food in the same span, thus making it possible for a larger population to survive on pretty much the same harvest.
This is something scientists often make progress in, and as we speak, research is also being done on cloning food in order to produce more of it. If you could grow meat that is not attached to an animal and a laboratory, and also speed up the growing process, you could provide a lot of people with food, that might eventually not only cost less to produce, but also require less energy to produce. One kilogram of meat requires 15000 litres of water to produce, and a handful ton of food, for the, say, cow to reach an agreeable size to then slaughter.
Additionally, every step in the food chain lose 90% of the total energy produced just to power itself. A nice comparison is cars, where 90% of its total energy consumption is used to cancel out the effect of gravity, friction and air pressure (or whatever its called). This is why the food chain rarely exeeds 4 steps, as the energy provided from the food in the end is minimal, and why the animals at the top pf the food chain is rarely used as a food source by another animal.
That is why if everyone would be vegeterians, the earth could support almost 10x the population it could currently support, simply because vegetables provide us with more energy then meat do. However, that theory is slightly flawed, as this would also mean we as humans would need to spread out over a larger area, and thus we would be unable to grow enough food to support our entire population.
If we could scientifically clone our food, and produce it that way, then we could support a much larger population. However, it requires a significant amount of progress, as it is currently extremely cost inefficient to clone food. Not only that, it is also somewhat unethical, and most consider it morally wrong. There's also the issue of whether it would taste the same or not. Would you pick up a pack of cloned meat over normal meat if you went out shopping?
Anyway, nature have many ways of preventing a population of ANY animal to become too large. Ants have a special type of fungus that infects the ants and is capable of making a whole hive extinct.
When a population of an animal becomes too large, it also makes it more prone to infections and diseases. When we're close together, it increases the risk a pandemic will strike and kill us, as many people together means it have more places to spread, especially if it is airborne. More people also means it have more possible hosts to mutate in and become more dangerous and deadly. This is especially the case as we spend a lot of time close together with animals.
HIV, for example, originally developed from a monkey-virus called SIV. SIV in and by itself is rather harmless to humans, but as a new possible host were introduced to the mix, it mutated and became HIV. The virus itself is pretty much exactly the same, but has evolved to infect a new host. As most animals don't live in as large groups as we do, and the fact that most species are older then us, the viruses and the host have evolved to compliment each other nicely. It is not beneficial for a virus to kill its host, as it it requires a host to live, and spread to new hosts. Most animals, trhourh evolution, have a immune system capable of handling the diseases, but we as humans don't. So when a disease mutate and infects us humans, it is far more deadly to us then it is for the animal it originated from.
SIV and HIV, for example, have kind of a suction cup that floats around inside it. When it reaches a cell, it attaches to it, and attracts the other suction cups to hook on to the cell as well. It then sends it RNA inside of the cell, and the cell is then infected. Some other bacteria and virus work in a more subtle way, and sinks together. When it reaches a cell, it moves in close to it, which causes the cell to protect itself by building a kind of bubble around itself, which also happens to surround the virus. It then proceeds to turn itself inside out, which sends a lot of tis own RNA inside the cell.
Others take a more simple approach and just pumps the RNA inside the cell, like a reverse mosquito.
Either way, my point is, with a larger population, it gives various diseases time to evolve and adjust, and thus kill a larger population.
The second way nature controls population is through homosexuality. While there's not a lot of strong evidence towards it, there is evidence that show heavily populated areas have a larger homosexual population. While it can be due to other reasons, such as homosexuals from other parts of the country move there to more easily find a partner, it is still interesting.
The last reason, which almost exclusively apply to humans, is that there's no real natural selection. Heart diseases such as stroke are genetically passed on to kids, which means a larger and larger population are born with, or are more prone to get, heart diseases which causes them to die prematurely. As there's evidence that show some forms of cancer are genetically passed on to kids as well, such as breast cancer, a larger part of the population will develop these types of cancer. And as there's no natural selection to prevent these genes from being passed onwards, humans "devolve" in a way, which can be seen as a kind of population control. However, due to medical breakthroughs, these no longer kill us at a rate they should, so we've found our own way around it. It is still a form of population control, only one that don't work due to our intelligence.
:dur:
I sometimes think bringing a child into this world (as cliché as it sounds) WOULD be cruel.