Historians and anthropologists alike dismiss the so-called "civilizational tree" (although this is the first time I've heard that particular moniker applied). As an anthropologist rather than an historian, I can speak roughly to the anthropological community's view of this concept.

During the "Age of Exploration," European travelers encountered the diversity of human cultures around the world that had largely (previously) escaped their awareness: cultures in the Americas, parts of Asia, Africa, and Australia. The framework for understanding the origins of these cultures was, at the time, Biblical in nature, and so they were largely shorehorned into that organizational / interpretive model. Lacking a decent chronological model of humanity's existence (which wouldn't really solidify until the 20th century), and observing the often significant differences in technology and social practices and traditions, these travelers often created their own taxonomic systems for the peoples they encountered, based on things like metallurgy, religious practice, foodways, and so on.

Over time, it became increasingly apparent-- not only to these travelers / amateur "anthropologists," but also to natural philosophers (employing an embryonic version of the scientific method)-- that the Biblical framework no longer was appropriate to explaining the natural world, or the diversity of humankind. The genesis (pun intended) of this was in things like massive skeletons of animals unlike anything living in the modern era, and the extraordinary variety of human culture that simply couldn't be accounted for, no matter how broadly the Bible's accounts were interpreted.

Encountering peoples using vastly different technologies-- stone instead of metal, for example-- provided Europeans with evidence for the human origin of objects they had long interpreted as supernatural in origin (flint axes / "thunderstones," for example). Here was evidence that these things not only had been made by humans, but that at some time in the past, Europe had been populated by people who made tools from stone before progressing to the use of bronze, iron, and steel. During this period, we see the initial development of basic geological and chronological concepts: Steno's Principle of Superposition, for example, which states that all things being equal, in a stratigraphic sequence, the deeper you go, the older you get; and the 3-age system developed by Christian Thomsen, who laid out the stone / bronze / iron tripartite technological chronological sequence. These were some of the earlier scientifically-minded efforts to organize the history of the world into a sequence based on observed evidence, and to derive the history of the world from depositional relationships in geological and anthropogenic sequences.

What this also did, however, was strongly imply a very concrete notion of "progress" and directionality of that progress. I.E., if Europeans had once used stone tools and now used iron, and existing cultures could be found that were using stone but had not developed iron technology, then the idea that those cultures had not progressed to the level of development of Europeans was implied.

By the 19th century, the notion of increased complexity over time, and change / evolution, was solidified with Darwin's work, cutting edge for the time. Scientists of the era, as they do today, took these innovative ideas and worked to apply them wherever they could. Not only to biological systems, but also to cultural ones. To some early anthropologists, so-called "social Darwinism" seemed to match and help explain the (limited at the time) evidence of human cultural diversity around the world. Different levels of progress, observed in the then-modern era, seemed to imply different paces of development. And if the European cultural traditions and technology were viewed as the "pinnacle" of development (as these early anthropologists did), then those at different "lower" stages of development might be viewed in some way as deficient, since they had not developed as quickly.

All of this combined to produce a school of thought that placed human cultural development along a single continuum, simple to complex, or "primitive" to "civilized." Lewis Henry Morgan developed the now hilariously backward concept of a tripartite division of human cultural evolution: savagery, barbarism, and civilization (guess who was at the top of that). To Morgan and others of his viewpoint, human cultures progressed through various technological and social changes that marked their graduation to the next level of development. Similar evolutionary sequences were developed for the evolution of religious systems (E.B. Tylor: animism, polytheism, monotheism, science).

It's important to remember that these folks were working with what they had. In many ways, they didn't know any better. This isn't Thomas Jefferson knowing full well that slavery was wrong, but keeping slaves nonetheless. This was people trying to work out ways of explaining and understanding human diversity with whatever information and explanatory framework they could devise. The fact that today we view it as extraordinarily racist and ethnocentric is in large part a product of the advancement of the discipline that people like Morgan and Tylor initiated with their own work.

And likewise, the fact that this unlineal progression was mobilized as a convenient excuse for the harm that imperialism and colonialism by the European powers caused to non-Western cultures is not really Morgan's or Tylor's or their contemporaries' faults. They were trying to apply modern scientific ideas (natural selection, adaptive advantage) to their own questions. We do the same thing today. And much like modern anthropologists' work can be misrepresented by people with a political agenda (see the legitimate research done in biological anthropology and its mis-representation by the racist proponents of things like "human biodiversity"), so too was the work of the 19th century anthropologists mis-used. (note: not to suggest that some of these folks were not also pretty racist and ethnocentric overall. That's a topic for another post, but they were in many ways, even for the era-- look up Ales Hrdlicka, for example.)

The problem is that the late 19th century folks lacked a lot of information about human cultural diversity and its historical roots, and the basic chronology of the human species. They were also not strictly anthropologists, but engaged mostly in armchair speculation.

By the early 20th century, new ideas developed in opposition to these unilinealists. People formally trained as anthropologists began to engage in actual field studies with other cultures, especially in the Americas. Folks like Franz Boas (one of the few times that the moniker "father of" is appropriate-- his ideas still inform and guide modern anthropology) began, with their fieldwork, to develop a more complete and fleshed out notion of human cultural diversity. They recognized in their work that progress is not unilineal. Technological systems are a product of human need and necessity, and of historical, environmental, and social contexts. And they are not the sole indication, or even the best indication, of cultural complexity. Boas's notion-- that each human culture is the unique product of its own unique history, which includes environment, interaction both internally and externally, and a number of other factors-- has been termed historical particularism in the anthropological literature. And for the most part, that's the way that cultural development and change is viewed by anthropologists today, albeit with updates as new information (like increasingly well-developed chronology of the human species) has dropped into place.

I have a follow-up question. I was personally well aware that today historians don't think like their 19. century collegues. However the way I see it, the history as known by most people still largely draws from a social darwinist model. Your average person doesn't exactly have much critical thought and haven't studied postmodern accounts. When you say you can't make simple value judgements and set up clear lines, an average person will think sure I can, I have much more stuff and much more opportunity avalible to me than a medieval peasent or an Amazonian tribe member. He/she is falling to judgements and biases embedded in themselves, but they can't help it most of the time.

Or put it another way, if I think back to my highschool history (a decade ago), with each new chapter I could generally expect more stuff to memorize and more complex concepts to study.

I think this issue is huge because such fundamental divide between popular and academic views on history simply can't lead to good. I can see this in my country where nationalist intepretations are popular and some people accuse historians as distorters, dogmaticists, in extreme cases outright liars and traitors, fuelling a culture of alternative facts and distrust.

How does contemporary history education tackle this issue? Are curriculums changing around the world? Will your common folk a few decades from now think in terms like todays historians?