What was the spark that, billions of years ago, kickstarted the process of evolution that has brought us life as we

Question: What was the spark that, billions of years ago, kickstarted the process of evolution that has brought us life as we know it today?
- Keywords:
  evolution,
  life,
  start,
  trigger
Asked by amber4 to Amy, Karen, Sarah, Vijay, Will on 8 Jun 2012. This question was also asked by meg123.
- Sarah Martin answered on 8 Jun 2012:
  
  Hi Amber!
  
  There’s a great video on the origin of life here:
  
  Enjoy!
  
  Sarah
- Karen Reed answered on 8 Jun 2012:
  
  Wow that’s a BIG question – I’m not sure if anyone really knows how life started, but we know it all started with single cells and they came about because the conditions were just right to allow things to clump together and (I assume) survive better together than apart.
- Amy Birch answered on 9 Jun 2012:
  
  I don’t think I can beat Sarah’s video, David Attenborough can explain it much better than me! 🙂

Question: What was the spark that, billions of years ago, kickstarted the process of evolution that has brought us life as we know it today?