I'm in a spot (not a block) with my work in progress, so I've taken a couple of hours off to do some gardening, read the local paper, have a cup of tea and write this post.

If group members have time, they may be able to help me with their interesting opinions.

My book is about the first year of human colonisation of an exoplanet, five light years from Earth. I am proceeding very carefully with the concepts involved in setting up a human colony. I won't go into detail, because it's not exactly pertinent to the question I am about to ask. The planet in question is a "terra nullius". It is a little like Mars, with hardly any life on it, apart from bacteria.
However, the bacteria are stimulated by the human arrival and begin moving towards intelligent life. (I know, I'm collapsing millions of real-time years, but I'm allowed because this is SciFi and speculative.)

My question is: Seeing what is happening to the bacteria, what can the human colonists do? Should they abandon the colony and leave the bacteria alone to follow a natural evolutionary course?