When the Earth was much younger it was not covered in life like it is today, which made it hard for the little bit of life there was to spread out. 

Living things like to take up residence in places that are abundant in the things they need to survive and difficult to digest rocks were not high on the list of survival needs. 

That was the case until giant fungi came along and changed everything, making life on land possible and forever changing the face of the planet. 

Check out this extremely interesting and informative video from PBS Eons and then let me hear your thoughts in the comments section below!