Wednesday, June 21, 2017

Gen Eds 11: The First Humans

The end of my world history posts! And only after ten months.

This is part of my "General Education in a Nutshell" series. The series consists of ten subjects you might study in a general education or "liberal arts" core at a university or college. The first topic in the overall series was philosophy. This is the final post in the world history part:
1. The last post began to delve into some sensitive waters. An Archbishop named James Ussher in 1650 suggested that God created the world in 4004BC. This date fits with a fairly literal reading of the chronologies in Genesis.

However, in my last post I gave some dates from mainstream archaeology that go back further than 4000BC. Archaeologists date the walled city of Jericho back as far as 8500BC and Çatalhöyük as far back as 7000BC. These dates would require at the very least for the genealogies of Genesis to be significantly incomplete.

2. On the one hand, the fingerprints of history in Genesis coincide extremely well with the history of Mesopotamia from the previous post. We have Abraham at the time of Hammurabi. We trace him back to Ur in Sumer. And in the area of Sumer we have the beginnings of civilization. This is the area from which the ziggurat arose, like the Tower of Babel. There is evidence of a devastating flood in this area. Even Genesis points to the Garden of Eden being in the area of the Tigris and Euphrates (Gen. 2:14).

These breadcrumbs point back to about the same time as Ussher in the right region. The birth of human history is exactly where Genesis locates it--in Mesopotamia around the fourth millennium BC.

3. According to our previous post, human "history" began with the beginning of writing in the late 3000s BC in the area of Sumer. However, the current state of archaeology wants us to push back further, back to an "agricultural revolution" around 10,000BC. The current state of paleontology, which goes back beyond that point, wants to push back even further. How are we to fit these dates with the Bible?

In the last two decades, genetics has caused us even more problems. The mapping of the human genome, according to the current state of research, suggests that a common female and common male ancestor might have lived somewhere between 120,000 and 150,000 years ago in Africa. But not at the same time. [1] The current estimate is that "The DNA in current humans could not have come from a pool of fewer than approximately 10,000 humans." [2]

These theories of course are probably not in anything like their final form. We are in a dialog between Scripture and science, between possible interpretations of the Bible and possible interpretations of science. For example, John Walton's proposition is that perhaps Adam and Eve were royal representatives for a community of early humanity at some point in our early history. [3]

According to one theory, all humanity can be traced to East Africa about 70,000 years ago. According to current theory, Homo sapiens left Africa about then. So following Walton's theory, we might speculate that Adam and Eve ruled the Homo sapiens of East Africa some time before 70,000 years ago.

This of course is speculation, a discussion that hasn't hardly even started. For many, it is a conversation that should never start.

4. My goal in the rest of this post is simply to sketch out what seems to be the current dominant timeline for humanity among experts in this area at large, to do with as you will. My dates are based on Yuval Noah Harari's book, Sapiens: A Brief History of Humankind. It is a clearly secular book.

According to the current theory, a female ape had two daughters 6 million years ago. One would become the progenitor of all chimpanzees The other would become the mother of all humanity.

In this theory, about 2.5 million years ago, the genus Homo originated. This is not Homo sapiens or human beings as we are. These were animals in our genus, just as a lion and a tiger are in the same genus Panthera. According to the theory, this new genus Homo emerged from a genus of apes called Australopithecus.

Again, the current theory sees Homo sapiens emerging as a new species in Africa about 150,000 years ago. There were other "humans" around in the world at that time: Homo erectus, Homo neanderthalensis, Homo denisova. According to DNA, about 1-4 percent of Middle Eastern and European DNA is Neanderthal, and about six percent of Aboriginal Australian is Denisovan DNA.

So these "humans" would have intermingled a little, perhaps until as recently as 50,000 years ago. Neanderthals may have lasted until 30,000 years ago.

The success of these broader humans was the use of fire, going back as far as 300,000BC according to the current theory. Because humans could cook their food, they could eat all the needed food for a day in an hour, as opposed to the five hours of chewing raw food that chimpanzees need to do a day.

They were not particularly spectacular in comparison to other predators out there. In fact, some speculate that tools may have developed so that humans could break into bone to eat after the more skilled predators were done eating off all the meat from a kill.

There are no longer any other humans other than Homo sapiens. We apparently eliminated the others, according to the "Replacement" theory.

5. Some then suggest that the real point of origin for humanity as we know it took place about 70,000 years ago in East Africa. Yuval Harari calls this moment the "Cognitive Revolution." According to the current theory, some Homo sapiens had left Africa about 100,000BC for the Middle East, but they had not managed to compete against the Neanderthals, who actually had bigger brains.

But something changes in between 70,000 and 30,000BC, on this theory. Harari calls this chapter, "The Tree of Knowledge." Unlike Neanderthals, so the conjecture goes, Sapiens trade over long distances. Sapiens can coordinate with larger groups than small bands. Most importantly, Sapiens can imagine--they can construct realities like founding stories and legal fictions. They can not only talk about what is. They can talk about what could be.

6. In this theory, these Sapiens were all hunter-gatherers. They did not live in any one fixed location. They traveled to find food where they could. They ate on the spot what they could.

The next revolution, according to Harari, is the "Agricultural Revolution." This is when Sapiens transitioned from being a mostly hunter-gatherer species to becoming a farming species. In one place he mentions 12,000BC, but in another he suggests 9500-8500BC.

"Wheat and goats were domesticated by approximately 9000BC; peas and lentils around 8000BC; olive trees by 5000BC; horses by 4000BC; and gravevines in 3500BC" (77). "By 3500 BC the main wave of domestication was over" (77-78). "By the first century AD the vast majority of people throughout most of the world were agriculturalists" (78).

The rest is history. Agriculture tied down people to locations. Locations prepared the way for cities. Cities expanded the number of people in one place. Once the number moves into the hundreds, we need writing. We need bureaucracy. We need administration. We need collective imagination. We need to control violence. We need to organize warfare.

Here endeth world history.

Next Week: Chapters 1-8 of Sapiens

[1] E.g., Sequencing Y Chromosomes Resolves Discrepancy in Time to Common Ancestor of Males versus Females

[2] Both Tremper Longman III (vi) and Scot McKnight pass this idea along (xi) in Adam and Genome: Reading Scripture after Genetic Science. These are faith-filled biblical scholars who believe in the inspiration of Scripture but also feel the need to take science seriously in the name of truth. See also the faith-filled scientist, Francis Collins, The Language of God.

[3] The Lost World of Adam and Eve: Genesis 2-3 and the Human Origins Debate.


Jennifer Brien said...

"According to the current theory, a female ape had two daughters 6 million years ago. One would become the progenitor of all chimpanzees The other would become the mother of all humanity."

Kinda-sorta, but confusing. At some point no later that that, there was a female who was direct ancestor in the maternal line to both chimps and humans, but her daughters and many other individuals living at the same time would also have been ancestors of both.
We are also the descendants of countless females whose line ended only in sons.

Ken Schenck said...

Thanks for the clarification!

Martin LaBar said...

An ambitious project, but well done. Thanks.

John Roth said...

The field of human origins is changing so swiftly that anything in book form is woefully out of date. The split between the lineages leading to modern chimpanzees and modern humans probably took place over many generations and many tens of thousands of years; it would be impossible to trace it back to any specific individuals.

The out-of-Africa migration between 50 and 70 thousand years ago is only ancestral to non-sub-Saharan Africans. The history within Africa is much more complex and very poorly understood. The out-of-Africa migration also mixed with Neanderthals and an even less understood group called Denisovans, leaving a few percent of DNA from each.

When our lineage acquired behavioral modernity (that is, became essentially human) is an extremely contentious topic, especially since it had to have happened long enough ago to account for the essential similarity between Africans and non-Africans. That rules out anything that happened after the out-of-Africa migration.