Digging in sediments in northern China, evidence has been gathered by scientists suggesting that complex life-forms emerged much earlier than they had previously thought.

• Aevidence has been gathered by scientists suggesting that complex life-forms emerged much earlier than they had  
• Bevidence gathered by scientists suggests a much earlier emergence of complex life-forms than had been  
• Cscientists have gathered evidence suggesting that complex life-forms emerged much earlier than  
• Dscientists have gathered evidence that suggests a much earlier emergence of complex life-forms than that which was  
• Escientists have gathered evidence which suggests a much earlier emergence of complex life-forms than that