Earth in the Goldilocks position.

[Leo-Bloom]

Clearly the Earth is just in the right orbit, neither too hot or too cold, for life to have developed.
How much nearer to the Sun, or further out, would have meant no life on Earth?

[Clanad]

Only 4% closer or 1% further (Michael Hart, "Habitable Zones about Main Sequence Stars," )

[rov1200]

I see now that even the intelligent fraternity admit that life is too complicated to be an accident or even to have come from evolution.

Its called the 'third way' or intelligent design but in this case not god like.

[fo3nix]

By Goldilocks position, I assume you mean where it is 'just right' for life on Earth.

But this is incorrect.

It happens to be 'just right' for this type of life.

Closer to or further from the Sun, it could still sustain life, just not quite as we know it.

[wildwood]

I am with fo3nix. There is life on Earth that lives at over 100� C. around geyser/hotpool outlets (even on the ocean bottoms) and also in subzero temperatures around the Poles.

Mammals and birds couldn't stand much of an temperature difference, but some other life can and would evolve to fill ecological niches.

[jake-the-peg]

Estimates of 5% may be misleading because they are based on the "Goldilocks zone" for this planet as it is now. Such a zone for any planet may be much much wider.

Remember that the long term carbon cycle of a planet has a major effect. Mars is no longer geologically active and is now much colder than it once was.

Remember too that without the natural Greenhouse effect the average global temperature would be 25 degrees below.

James Lovelock's Gaia hypothesis (http://en.wikipedia.org/wiki/Gaia_hypothesis)
suggests that organisms can have an active role in maintaining the climate of a planet to be suitable for themselves.

This originally met with a lot of skepticism not least from Richard Dawkins. Lovelock then came up with the "Daisy World" mode showing how in principal a feedback mechanism of this type might work. http://en.wikipedia.org/wiki/Gaia_hypothesis#D aisyworld_simulations

Which satisfied these objections.

Because organisms evolve as the planet's climate evolved an Earth in a different position might have resulted in very different life forms, or different life forms that affected the climate in a different manner to bring about a climate similar to the one we have now