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This week we learn about the ancestral connection of H. antecessor, the age of Kabwe, have a published juvenile H. naledi, and a 2 million year old H. erectus in the cradle!
I'm going to try summarize why this rocks! (Or is at least partially fossilized).
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I'm going to try summarize why this rocks! (Or is at least partially fossilized).
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The most important question is, of course:
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H. erectus is the easiest one to start with. Maybe. We learn in school that H. erectus is when we start seeing larger brained, possibly running/hunting, all over Eurasia and Africa, larger bodied Homo. But the scientific consensus is... well... complicated.
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This is primarily because H. erectus, as a "species" is highly variable in terms of when they lived, where the earliest specimens are found and even in terms of brain and body size.
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Some of the earliest finds are found in Eurasia. This includes the Dmanisi hominins (in Georgia, dated to 1.8 mya). If you consider evidence for erectus to include stone tools, some have argued their presence in China super duper early (2.1 mya).
(5/n) https://ui.adsabs.harvard.edu/abs/2018Natur.559..608Z/abstract
(5/n) https://ui.adsabs.harvard.edu/abs/2018Natur.559..608Z/abstract
And here we have a H. erectus juvenile, dated to 2mya, not just "in Africa", but in South Africa! That's the whole other side of Africa, at a super duper early date too!
(6/n) https://www.nationalgeographic.com/science/2020/04/fossil-skulls-rewrite-stories-ancient-human-ancestors-homo-erectus-paranthropus-robustus/
(6/n) https://www.nationalgeographic.com/science/2020/04/fossil-skulls-rewrite-stories-ancient-human-ancestors-homo-erectus-paranthropus-robustus/
As the article says, near this time we have Au. sediba, P. robustus and other hominin cousins which appear more ape like in cranial morphology.
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The article says: "Regardless of which of these species emerged first, one thing is clear: Over a million years later, only Homo erectus still walked the Earth."
BUT at 300 kya - 1.7 million years later - H. naledi is hanging around in caves!!!
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BUT at 300 kya - 1.7 million years later - H. naledi is hanging around in caves!!!
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When it comes to cranial morphology, H. naledi shares a lot of features with erectus, but has a very small brain. And, nearby naledi, but not associated directly, are pretty dope stone tools.
What happened to erectus?
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What happened to erectus?
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The naledi peeps have argued that naledi could have made these tools, and that the assumption they didn't is based primarily on the fact that we're all size-ist towards smaller-brained hominins. Coz, let's face it, otherwise naledi seems pretty... interesting.
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Why they interesting? Coz they're found deep in a cave with no evidence for a skylight to fall through, and almost no other animal bones.
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And then, also dropping like a @Beyonce album, is this:
(12/n) https://www.nationalgeographic.com/science/2020/04/puzzling-skeleton-reveal-ancient-human-relative-homo-naledi-grew-up/?fbclid=IwAR0IfaDXyUMa7B446uXIlCj1hBDzeVuP9yr4l3vg400o_P07mYGWZP39u5g
(12/n) https://www.nationalgeographic.com/science/2020/04/puzzling-skeleton-reveal-ancient-human-relative-homo-naledi-grew-up/?fbclid=IwAR0IfaDXyUMa7B446uXIlCj1hBDzeVuP9yr4l3vg400o_P07mYGWZP39u5g
This is a juvenile naledi. And juveniles are cool because they tell us SO MUCH about the way an animal (or hominin) grows. And finding their bodies is so rare!
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We are really interested in the fact that human children take so long to grow up. This has been hypothesized to allow us time to "learn how to be human".
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To understand this, two things need to be done:
1) Find out the comparative age of the individual.
2) Find out the ACTUAL age it died.
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1) Find out the comparative age of the individual.
2) Find out the ACTUAL age it died.
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The authors argue this:
"If H. naledi matured as fast as earlier hominins... then DH7 died between the ages of 8 and 11 years old. If H. naledi matured more slowly like modern humans and Neanderthals, however, DH7 would have died between 11 and 15 years old.
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"If H. naledi matured as fast as earlier hominins... then DH7 died between the ages of 8 and 11 years old. If H. naledi matured more slowly like modern humans and Neanderthals, however, DH7 would have died between 11 and 15 years old.
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That's a wide age range, so the next step is to find the actual age of death by, essentially, counting the rings of enamel in the teeth. This is slow work, but is currently in the process of being done.
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If naledi is maturing slowly like humans... what would this mean about our interpretation of their "sophistication"?
(I'm not answering this one, just being unnecessarily suggestive).
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(I'm not answering this one, just being unnecessarily suggestive).
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But HOLD ON ONE MINUTE! Before you start getting too big for your britches, did we all forget Kabwe, a large brained hominin from Zambia?
When was this guy around?
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When was this guy around?
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Well, according to new research, also around about 300kya...
(20/n) https://podcasts.google.com/?feed=aHR0cDovL3d3dy5uYXR1cmUuY29tL25hdHVyZS9wb2RjYXN0L3Jzcy9uYXR1cmUueG1s&episode=ZTBhNjMyOWEtODRlYi00YjM2LWJiOGEtMjFkMThhNDcxNDJh&hl=en-ZA&ved=2ahUKEwjqmpnQhszoAhUF3xoKHaSyAdEQieUEegQIAhAE&ep=6
(20/n) https://podcasts.google.com/?feed=aHR0cDovL3d3dy5uYXR1cmUuY29tL25hdHVyZS9wb2RjYXN0L3Jzcy9uYXR1cmUueG1s&episode=ZTBhNjMyOWEtODRlYi00YjM2LWJiOGEtMjFkMThhNDcxNDJh&hl=en-ZA&ved=2ahUKEwjqmpnQhszoAhUF3xoKHaSyAdEQieUEegQIAhAE&ep=6
So now we have hominins of all different brain sizes living in Africa for a long long long time. What were they all doing? Were they just keeping their distance? Were they best buds?
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Just like Europe with it's hobbits and Denisovans and Neanderthals, running around causing havoc to Middle Pleistocene models, Southern Africa was like Middle Earth!
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But what about us? Who are we more closely related to? Where did we come from?
Now, I'm definitely not answering this question, but the awesome thing about advances in ancient molecular analyses, is that we are getting closer to the truth.
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Now, I'm definitely not answering this question, but the awesome thing about advances in ancient molecular analyses, is that we are getting closer to the truth.
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DNA doesn't always preserve the best, but by studying the molecular sequence of proteins, researchers were able to look at H. antecessor to try figure out, well...
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For context, antecessor is the earliest hominin in Europe. If we pretend Georgia isn't in Europe, of course. Some have argued it's an early Heidelbergensis, or a European H. erectus.
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'“We see that antecessor falls as a sister group—close, very close—to the branch that leads to us,” Cappellini says.'
This means that who antecessor is, they close to our shared granddaddy or grandma with our faves: Neanderthals and Denisovan.
(26/n) https://www.sciencemag.org/news/2020/04/mysterious-human-ancestor-finds-its-place-our-family-tree
This means that who antecessor is, they close to our shared granddaddy or grandma with our faves: Neanderthals and Denisovan.
(26/n) https://www.sciencemag.org/news/2020/04/mysterious-human-ancestor-finds-its-place-our-family-tree
We have so many hominins running around the landscape, and it's so easy to get tied back into that argument of "who are responsible for us". I think, though, that we need to try forget about the tree-like analogy for our ancestry.
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Once again, that analogy of the braided stream is probably far more apt. Even if lineages diverge, the potential for them to come back together was possibly around for a long long time.
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And while we learned a LOT more this week, there is still SO MUCH MORE to learn. I hope this helped put things (as I understand it) into context.
Stay safe!
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Stay safe!
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