09-22-2015, 09:53 AM
In what sense is it 400M years old? A system that's only been around for 400M years could have captured an interstellar rogue planet that's actually much older and, while it would have to survive a heavy bombardment period as the local accretion disk settled out, it could skip the molten-surface Hadean era.
That said, much faster development of complex life could all happen as a result of a single happenstance; Sex could be invented on, say, January 20 instead of November 11.
By way of explanation: We got single-celled life on Earth about 3650 million years ago. Map that to 365 days starting on January 1, and sex was invented on November 11. (We used to have an annual "Big Bang" party a couple weeks before Thanksgiving to commemorate the event). Between the origin of life and the invention of sex, only a little bit of biological evolution happened. The most significant event was the development of photosynthesis around March 30. But there were no real barriers to the invention of sex at some earlier point; the timing, as far as we know, is mainly a happenstance.
Anyway, once you get a method of genetic recombination working, evolution speeds up immensely and you can get complex life within a couple of "months."
That said, much faster development of complex life could all happen as a result of a single happenstance; Sex could be invented on, say, January 20 instead of November 11.
By way of explanation: We got single-celled life on Earth about 3650 million years ago. Map that to 365 days starting on January 1, and sex was invented on November 11. (We used to have an annual "Big Bang" party a couple weeks before Thanksgiving to commemorate the event). Between the origin of life and the invention of sex, only a little bit of biological evolution happened. The most significant event was the development of photosynthesis around March 30. But there were no real barriers to the invention of sex at some earlier point; the timing, as far as we know, is mainly a happenstance.
Anyway, once you get a method of genetic recombination working, evolution speeds up immensely and you can get complex life within a couple of "months."