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Test your knowledge of human evolution! I’ve provided a few facts related to some of the most fundamental topics discussed by anthropologists. Some of these ideas have been mentioned in my previous videos, so let’s see if you’ve been paying attention…

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Here are 5 things you should know about human evolution.

1. Our Closest Relatives: Chimps or Bonobos?

Charles Darwin himself suspected that we share a common ancestor with great apes [1]. Most people have now heard that we are about 98% similar to chimpanzees genetically. This is based on a study published in 2005 that compared the genomes of chimpanzees to humans [2], essentially confirming what Darwin hypothesized over a hundred years ago.

But, many people are unaware of our relation to another species of ape - the bonobo. Bonobos are similar to chimps. Physically, they are indistinguishable from the untrained eye. Socially, they are very different. Chimpanzees live in male-dominated, territorial groups and often display aggressive behavior to settle disputes within the dominance hierarchy. Bonobos on the other hand live in female-centric groups, that are less hierarchical.  Moreover, they opt to solve their problems with sex rather than aggression.

Given these two contrasting social worlds, which species are humans more related to? We are equally related to both. How so? Simply, chimpanzees and bonobos split into different species after we split from the common ancestor to all three of us. 

One of my college professors used a great analogy to describe this sort of speciation. She compares it to a train. At the first train station, one ape species hops on. That ape is the common ancestor to all three species. Then, 5 million years ago, some of them got off at the next stop. They evolved into the human lineage while the rest of the species stayed on the train. At the next stop, 2 million years ago, the rest of the apes got off and split into two populations and settled in different locations. They in turn evolved into bonobos and chimpanzees separately. 

So, at the time of our leaving, there was no distinction between chimps and bonobos. We are equally genetically similar to both. What are the implications of this considering their opposites in sociality? It suggests that we have the capacity for both chimp-like aggression and bonobo-like egalitarianism.

2. The Earliest Evidence of Anatomically Modern Humans

The mysteries of our origins are largely the reason for so many of us getting into the fields of anthropology and archaeology. And just when we think we have solved some of those mysteries, we are reminded of our ignorance. The date and location of the oldest Homo sapiens is an example of this. 

For years, it was believed that our species originated in either east or southern Africa sometime between 100,000 and 200,000 years ago. We now know that those locations and time ranges are inaccurate. The earliest evidence we have of anatomically modern humans actually comes from North Africa, in Morocco, and dates to approximately 300,000 years ago [3]. 

Many of the archaeological discoveries we find are due to things like construction projects that inadvertently expose unidentified sites. This site was no different. Mining operations unearthed human fossils in Jebel Irhoud, Morocco in 1960. Ever since, archaeologists have been tasked with researching these finds. The most recent discovery encompassed an adult skull and mostly facial bone fragments. Analysis of the size and shapes of these bones show that they are more closely related to that of modern Homo sapiens than those of more archaic species like Homo erectus or Neanderthalensis.

The research team performed thermoluminescence dating to determine this age of 300,000 years. 

3. Homo sapiens And Neanderthals Interbred

Homo sapiens was not always the only human species on the planet. For many years, our ancestors shared the earth with other human forms. Homo neanderthalensis, or the Neanderthals, was one of these other species. They were shorter, stockier, and mostly resided in the northern latitudes of Europe and Asia. 

It is believed that the Neanderthals went extinct around 35,000 years ago. Considering that we have evidence of Homo sapiens as far back as 300,000 years ago, there was a span of roughly 250,000 years where these two species could have come into contact with one another. And they certainly did by 70,000 years ago, once Homo sapiens were migrating out of Africa into the Middle East and Europe.

What did this contact look like? Was it brutish and war-like or peaceful and cooperative? We may never know exactly, but evidence suggests that Sapiens and Neanderthals were often more than just friends. They were mates.  

In 2010, Richard Green and colleagues performed a genome sequence on Neanderthal remains, comparing it to that of living humans. They concluded that modern humans outside of Africa carry approximately 1-2% Neanderthal DNA [4]. This strongly suggests that interbreeding between early modern humans and Neanderthals occurred and that we carry their genes in us today.

4. Culture Evolves Too

Just as the biological human form has changed over time, so too has our culture. No culture is completely static. Each consists of minor and major alterations that accumulate over time. Given enough of these modifications, a new culture may emerge that is sufficiently distinct from its predecessor to be considered unique.

Importantly, cultural evolution is not a linear process. Societies don’t evolve from “barbaric” to “civilized” on a measurable scale. Rather, much of what influences a culture’s evolution is relative to its environment. The adoption of thick, heavy clothes for example is something more relevant to groups of people in colder climates. 

Religions and belief systems can also change the trajectory of a group’s cultural traits. Influenced by Zen Buddhism’s focus on simplicity and the present moment, haiku poetry captures fleeting moments of nature and human experience with brevity and depth.

One study has shown how music, an artistic cultural trait, evolves. Researchers looked at how folk melodies change over time. They found that these changes are consistent with analogous principles that underlie genetic evolution [5]:

Put simply, notes that are more rhythmically important are less likely to change, just as genes that are more fundamental to an organism are generally more stable and mutation-resistant. 

5. Earliest Evidence Of Controlling Fire

Speaking of culture, one of our species' earliest innovations was the control and use of fire. We don’t know the exact moment when this ability was realized by some archaic human, who just so happened to strike together the two types of rock necessary to manifest a spark. That being said, we can approximate when and where some of the earliest uses of this novel technology occurred.

While it is still debated, some of the earliest evidence we have of humans using fire comes out of Wonderwerk Cave in South Africa [6]. Wonderwerk Cave is situated within the Kuruman Hills of northern South Africa and is known to have been occupied by various human populations throughout prehistory.

Not all of these species were Homo sapiens. Homo erectus, a precursor to Homo sapiens is believed to have occupied this cave. This is supported by the presence of stone tools, called the Acheulean industry, which are often attributed to Homo erectus. Archaeologists recovered plant material and bones from a layer of soil that also included these Acheulean tools, suggesting they date to around the same time. They date this layer to about one million years ago.

After taking samples of these remains and subjecting them to microscopic analyses, the researchers concluded that there is evidence of burning. One reason, among others, why they suggest that this was a controlled burning and not a wildfire is because the temperatures did not reach wildfire levels. The temperatures did not surpass 700 degrees Celsius, which would be congruent with the suggested “light plant material” that would have been used to fuel the fire.

Conclusion

Those were five facts about human evolution that you should know. There are plenty more, so if you enjoyed this video let me know with a like and a comment, and I’ll surely make some more! Also, make sure you click that subscribe button to get notified when I post future videos. 

Lastly, feel free to leave any topic suggestions in the comments below. I want to keep making videos you guys love, so I need as much feedback as I can get!

References:

[1] Darwin, C. 1871. The descent of man, and selection in relation to sex. London: John Murray.

[2] Chimpanzee Sequencing and Analysis Consortium. 2005. “Initial sequence of the chimpanzee genome and comparison with the human genome.” Nature 437(7055):69-87.

[3] Hublin, JJ., et al. 2017. “New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens.” Nature 546:289–292. 

[4] Green, R., et al. 2010. “A draft sequence of the Neandertal genome.” Science 328(5979):710-722.

[5] Savage, P., et al. 2022. “Sequence alignment of folk song melodies reveals cross-cultural regularities of musical evolution.” Current Biology 32(6):1395-1402.

[6] Berna, F., et al. 2012. “Microstratigraphic evidence of in situ fire in the Acheulean strata of Wonderwerk Cave, Northern Cape province, South Africa.” PNAS 109(20):E1215–E1220.

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