These white dots pulse slowly on my scanner sometimes, on various planets. They will show for about 1 second, then not show for a few. I took the picture underground as at this particular moment there were a lot showing, but they also appear above ground as well.
I have tried to track them, they are usually a long way away. The only time I have been "successful" is when I found a structure of some sort, but I cannot be sure the dots actually mean "structure is here," as other times I have tried to track them and have seen nothing.
I'm starting to think that they are life-forms, but do not have enough data to corroborate.
Also, no, they are definitely NOT waypoints.
Best Answer
I just answered this as part of my answer here, but I'll rework it for you, since your question is sufficiently different than the linked one.
When you use the Analysis Visor, it will show three things:
These indicate creatures that you have already scanned.
These indicate creatures that you have not yet scanned.
From my experience with the game so far, the white dots do indeed appear to be creatures. They only stay for a few seconds, presumably so that creature finding isn't an easy task, since the reward for 100% is so high. The game does not seem to be intuitive enough to tell you if you (from a distance) if you have scanned them or not. However, the closer you get to a dot, it will turn green or red depending on what you've done for that species.