AC,
if only Australians wgould start ehating ‘roo and wallaby we’d be a healthier nation and the land would be less degraded.

Extinction is natural.
One species can grow to dominate a region, and push another out of existence.
Those who see this as normal are quite right.
The problem for us is that the human species has been far too clever at surviving.
It has thus overpopulated the planet.
It is now necessary to reassess our use of the planet's resources.
We need to take from it what we need to survive, and take only that.
And, where possible, replace and replenish what we use.
Otherwise, we will simply eat ourselves out of house and home.
And should this happen, we will be relegated to some distant part of history?
I wonder which amimal would rise in mumbers to take our place?
I doubt it would be a plant

Ipso Fatso wrote "I wonder which amimal would rise in mumbers to take our place? I doubt it would be a plant.

Rest assured. Any animal which took our place would not be a plant.

Well I've never understood why people don't just make more species if they're so concerned about the number of species declining.

But the other thing I've never understood is why people keep saying, as Ipso Fatso has just said, that the world is overpopulated. What do they actually mean by this? The global average living standards are higher now than at any other time is history. We produce more food now than at any other time in history. Indeed food production is so high that I remember reading years ago that the number of obese people on the planet now outnumbers the hungry. So why do people think that we're overpopulated?

Dear thinkabit,

We are overpopulated because we are using up the resources of the world faster than they can be replaced. There is also an unequal distribution of resources. While many people are obese, many are also going hungry. We cannot continue our present rate of consumption and reproduction. It is unsustainable. Crunch time is coming, and it will be most unpleasant.

davidf: "We are overpopulated because we are using up the resources of the world faster than they can be replaced."

But that doesn't mean that we are overpopluated. To give you an hypothetical example why not: consider Mary, who has a small desk top gold fish tank with a single fish in it. Now Mary has accidentally purchased ten tons of fishfood flakes to feed the fish. So here the gold fish is consuming a finite resource (the 10 tons of food) faster than it can be replaced (Mary is never going to buy more) but it is NOT overpopulated because it will die of old age before it runs out of food. It is the same with us humans- we do use up resources but due to the fact, that we a) can recycle and b) can swap to other resources for most stuff, the rate we inexhaustibly consume resources is a non-issue since a human can only live about a century. If in the deep, deep future we do begin to run out of some critical resource, we can simply adjust our population by breeding less and let our population naturally decrease in size due to death by old age.
But we are nowhere that point yet, because there is no evidence that there exists any non-substitutable critical resource is or that will about to enter into short supply within a human's life-time. (In fact, humanity deciding to deliberately reduce our global population realistically probably won't ever need to happen- because machines will have evolved to completely replace humans before then. They already are starting to replace humans in first world countries. Birth rates in first world countries are plummeting because society doesn't need human labour so much anymore since machines can do a lot of the work. Machines are the next phase in the evolution of what's traditionally labelled "life" on the planet.

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