As a graduate student, I read numerous papers and articles which discussed the ability of hunter gatherers and early farmers to gather information and make sense of the resources available within their world. Most of these provided useful information or perspectives, and I am glad to have read them. However, nearly all of them made the same assertion - that the observations of these people are science.
The basic assertion is that the people who are reliant on their environment to get by are extremely observant of it, and capable of making predictions regarding plants and animals, as they need to in order to survive. This ability is typically referred to as "their science", asserting that it is the equal of "western" science.
Now, don't misunderstand me. If you spend much time studying hunter-gatherers and early farmers, you will be struck by just how well honed their observational skills are. They tend to be keen observers of the behavior/tendencies of plants and animals, and they have to be in order to survive. And while observation and prediction are vital parts of science, and in these peoples we can see how the raw materials for science are present in the human brain, science itself is another thing altogether. Science makes use of observation, prediction, and the sharing of ideas amongst peers, and shares these traits with the people discussed in the documents to which I refer, but it also makes use of numerous methods intended to root out observational bias, including structured studies, peer review, regular discussion and review of findings, and vigorous debate among a huge audience regarding findings. If it lacks these elements, then it really isn't science. But that doesn't make it somehow inferior, as it serves a somewhat different purpose and therefore should be expected to be different.
When part of a scientific exercise, observation of nature carries a certain amount of baggage and intention which is different from the baggage and intention of someone who is observing for the purposes of survival. Hunter gatherers are generally not concerned with how their observations fit into broader theoretical models, such as evolution, any more than a field biologist is concerned with starving should they fail to catch their quarry. A different set of needs, assumptions, and purpose are carried by the two different types of observers, and these influence what they observe and how they observe, making their activities different, even though they share many similarities and may be in many ways complimentary.
This assertion that the activities of hunter-gatherers and early farmers is a type of science (or, as it is often formulated, "their science") appears to come from a desire to make the people being studies or described seem more intelligent or noble than is often assumed, and to put their activities on intellectual par with "western" institutions. This came, at least in part, in reaction to centuries of Europeans and their descendants viewing all non-Europeans as somehow primitive. This assertion that the activities of hunters and gatherers was intended to show that these people are not primitives, but are, rather, quite sophisticated in their interactions with their environments.
The problem is that this is essentially the imposition of a "western" model onto people who live and think in very different ways. To assert that their activities qualify as science is to impose a particular frame of reference onto them which they would not recognize as part of their activity, and is, ultimately, just as condescending as to insist that their activities are "primitive". Just because observations are sophisticated, well-made, and intelligently considered, does not automatically make them science, as science requires another rather specific set of accompanying features. Moreover, to refer to them as science is to ignore the context in which they occur, to ignore the way that the people engaged in the activities view them, and, in short, to be a poor anthropologist. Moreover, the desire to "bring them up to our level", however well intentioned, is still steeped in the notion that we as western observers must ennoble the pursuits of other people in order to make them worthwhile (or at least show them to be worthwhile), which is about as condescending an attitude as one can take.
Hunter-gatherers are not generally engaged in science, not even "their science", and that's fine. They are engaged in the necessary observation and predictive activities for their circumstances. Recognizing that they are using well-honed intellectual abilities to pursue a goal is sufficient, and it shows them to be sophisticated, intelligent, and anything but primitive. There is no need to impose an outside way of viewing the world onto them in order to accept that they are showing the very traits of intelligence that make us all human.