The article seems to be making the point that the concept of memory lies on a spectrum, with the tree having a memory of having had a branch is at one end of th

The article seems to be making the point that the concept of memory lies on a spectrum, with the tree having a memory of having had a branch is at one end of the spectrum. The ant colony stuff is somewhere in between. In many senses what they are speaking of is what we refer to as "culture," as in things that are learned and passed down. When a memory of a path to a food source is passed down, it is simply because the senior ant walked the path while another followed. The senior ant wasn't consciously "teaching" the younger one so much. Regardless, all of these things lie along a spectrum.