3 Answers

Well according to the bible, God created all the plant life. The plant life would have created it's own seed. Or aliens could have brought seeds from their planet and dropped them here. You decide which answer works best for you :)

Great question, I would look to the subject of Geology for the answer.

Can you imagine if every detail of every living thing were in the Bible? It would be bigger than War and Peace!!

The answer is not yet known, but some think life arrived from another planet via a meteorite, some belive it arose from the hydrothermal vents in the sea, other that Dawin was correct when he spoke of 'warm pools' on land.

Creationists ( i.e Republicans and Muslims) think life arose in 6 days as per the Book of Genesis about 6,000 years ago.