The Perspective from Africa – Berhane Asfaw: Assessing Claims for the “Earliest” Homo sapiens

The Perspective from Africa – Berhane Asfaw: Assessing Claims for the “Earliest” Homo sapiens

(whooshing) (clicking) (beeping) (upbeat piano music) – [Narrator] We are the paradoxical ape. Bipedal, naked, large-brained, long the master of fire,
tools, and language, but still trying to understand ourselves. Aware that death is inevitable
yet filled with optimism. We grow up slowly. We hand down knowledge. We empathize and deceive. We shape the future from our shared understanding of the past. CARTA brings together experts
from diverse disciplines to exchange insights on who
we are and how we got here, an exploration made possible by the generosity of humans like you. (electronic music) (techno music) – Thank you very much. It’s a great privilege to share my opinion on this special topic because
in the last few years, you might have heard
repeatedly about claims made, the earliest of this, earliest of this. But my discussion is going to be focusing on the earliest homo
sapiens claims by people, by different researchers. Assessing claims of the
earliest homo sapiens needs first to evaluate the series of recent discoveries and
interpretations that figure prominently in
any current understanding of Pleistocene human evolution. For this, we need to have
the geochronological position of the fossils securely determined. Whenever somebody says that you found the earliest homo sapien, the first thing that we have to see is whether the dating is properly done, the geochronology is really there. Then after that, what you
have to do is, according to Lacruz et al., the modern
human face is distinct. That means what we have to
do first is we have to define what we are trying to say the
earliest whatever homo sapien. How do we define homo sapien? Just, you know, to use recent literature, according to Lacruz et al.
(2019), the modern human face is distinct from that of
the earliest hominid species in several important ways,
including the following: One, it is relatively small,
the face is relatively small and non-projecting, as you can see it. The face is very, very small. High, you know, big head but small face. Second, it shows a
depression, what we call the canine fossa, this is the depression. Especially the modern human face has this special
depression below the orbit. Third thing, I’m trying
to limit my description of homo sapiens. Just using certain features,
and we try to evaluate. We can use a whole suites
of morphology, or features, but for the purpose of my talk, I want to limit it just to
the face and small regions. It lacks a pronounced supraorbital torus. What we call the supraorbital
is just the eyebrow region. Homo sapiens like us don’t
have a huge browridge above our eyes. These features do not appear all at once in the fossil record, but crucial elements are already in place among
the earliest representatives of homo sapien lineage. This presentation will focus
on the hominid fossils. I’m using hominids, just only
for those who are bipedal. My hominid definition does not
include chimps and gorillas. I’m talking only about
the bipedal ones, okay? Because every since
classification used hominin. I’m not using hominin. I’m using hominid. Hominid is bipedal for me, okay? This presentation will focus
on those hominid fossils in Africa ranging
between one million years and 150,000 years. The reason why I do that is, one, they have to have to have
good stratigraphic hygiene. I use the word hygiene because
usually it is, it’s a mess. They have to be clean. You have to know exactly
where they came from. This is a word I borrowed
from Millard, 2008. It is a very important word. And the other thing is reasonably
acceptable age estimate. Because the age range
of some of the fossils that we are dealing with these days, are just enormous. But we prefer a certain age. Sometimes we prefer. It’s not because that’s the age, that is the preferred age. Which is scientifically unacceptable. Third, complete enough to make
a morphological observation to assess their taxonomic affinity. So there are so many fragments of bones, of, you know, hominid bones, ranging between one million
years and 150,000 years. But most of them are just bits and pieces. So to make this assessment, I really want to use only
those who do have mostly face, face included and the other parts. So when I choose that, there
are so few in Africa, very few. I used as base, as a
one million base level. I used the fossil that
my colleagues and myself found from Milawash, Daka. Because I am 100% sure about
its stratographic hygiene. It is clearly found from
one million years ago, based on Argon/Argon dates, and the stratography is clearly labeled. So it is with this understanding between one million and 150,000 years ago, within the lineage in Africa,
the African landscape, there were hominids that
evolved from Homo erectus, or whatever you call Homo ergaster. Some people prefer that. There are hominids of the lineage. These different populations
of hominids evolved incrementally through time,
incrementally through time. That means they add features every time. Adding features that lead
towards Homo sapiens. The advanced features
may not be manifested in all populations at once, but the Homo sapenization of the lineage has continued through time. So I see the lineage, it’s not, didn’t appear,
meaning the Homo sapiens package did not appear at once. It is a process. It’s increased characters through time. That’s what I see in the fossil record. Then my base, the top is what
I used is Homo sapiens idaltu. This is another one, which I’m 100% sure about its stratographic hygiene. Which is between 150 and
160,000 year boundary. And the age is undisputible. So the morphology, it has
clear Homo sapiens morphology, which we’ll go through it later. So the Homo sapiens
lineage may have originated around 500,000 years ago or earlier. So using this, their features,
the hominids may be treated in three groups or stage. Early, middle, and late stage. This is an arbitrary boundary
that I try to break them. The earliest, from the complete ones, which has part of the face. Which is the morphological
feature that we are manifested early in the lineage is
from Elansfontein/Saldanha. The age between 700 to 400,000
years ago, based on fauna. Recent faunal work suggested
older than 600,000. Maybe from 600 to one million. Browridge is, this is what
we call the browridge. The browridge is very
thick and undifferentiated. Undifferentiated means, in Homo sapiens, the middle part, which we
call the supercilliary part is a little bit thick. And the lateral part is thin. But Elandsfontein or Saldanha,
it’s thick media-laterally, which is a very primitive feature. The occipital torus is not strong. And that is common to all Africans. African, even African Homo erectus, they all have similar
kind of, we cannot use it, but what else do we use? The frontal is less constricted. This is the beginning
of Homo sapienization. The frontal part, this
part, is not constricted. In the earlier parts, in the
earlier groups in Homo erectus, this is, the lateral part
of the most lateral age of the browridge is very
wide, compared to the frontal. But in this Elandsfontein, the frontal is not very constricted. This is even less constricted, even than that of Broken Hill. This feature is more
advanced than Homo erectus. This is a beginning. And the cranial capacity is 1250 cc. It’s much bigger than Homo erectus. Much bigger than Homo erectus. That means brain expansion has started. This is a train going toward Homo sapiens. Okay, then the associated
tools, still Acheulian. That is the kind of tools that we have been seeing
with Homo erectus. Let’s go to the next group. This is Bodo. Bodo is the skull found
in the Middle Awash, in the area that I have been
working in the last 30 years. Age, 600,000 based on Argon/Argon dating. Cranial capacity is exactly
the same as Elandsfontein or Saldanha, 1250 cc. Much bigger than Homo erectus. The Homo erectus is under 1000 cc. That means the brain
has started expanding. Expanding, which is a direction that we see going towards Homo sapiens. High and arched temporal squama. When you see this region, in Homo erectus, it forms like almost like a straight line. But in these guys, it forms like an arch, it’s an advanced morphology. Supraorbitals differentiated,
meaning the lateral part is thin and the medial part is thick. This is a kind of morphology
that we see in Homo sapiens. So that means it’s they
are adding morphology going towards Homo sapiens. The associated tools are
Acheulian, like Homo erectus. But the morphology is changing. Unfortunately, the occipital
part is not preserved. What about Broken Hill? Age, unknown, we don’t know. Klein correlated the fauna
of Olduvai, Upper Bed Two through Bed Four. That age range is between 1.78 to 490,000. You can put it anywhere. But the temporal squama
is arched, like Bodo. It’s an advanced Homo
sapienization that we see. The upper scale of the
occipital, which is this one, is relative to the lower scale, it’s big. That is also an advanced feature. Frontal is transversally expanded. This is what we call the frontal. Unfortunately, it’s still primitive, because he don’t have a forehead. We have a forehead, which makes us different
from Homo erectus. But this guy, even though his big brain, but no frontal yet. But still transversally
expanded, it’s big. It’s a Homo sapienization that we call. Cranial capacity is a little bit bigger than Bodo and Saldanha. Now you can see, the
brain keeps expanding. The other features are not there. What about Ndutu, from
Tanzania, from Ndutu beds? Age estimates about 400,000 years old. See discussion in Millard. There’s so many discussions about the age. But about the age range is about 400,000. What is important about
this is cranial capacity, and though it is small, maybe a female, because there is a sexual difference between males and females, 1100 cc. Looks smaller than Bodo,
Broken Hill, and Saldanha. But it has more Homo
sapien features than them. The occipital is not flexed. You can see it from here. It’s an open occipital. In Homo erectus, it is flexed. But this one is really open. Especially the backside
is almost vertical. Has a post-canine fossa, something that we have never seen before either in Bodo, Saldanha, or Broken Hill. It is this part. We Homo sapiens have a
depression right here, which we call the post-canine fossa. So that is Homo sapien
character at that stage. The associated tools, still Acheulian. So the brain size is much
more than Homo erectus. The occipital has changed
towards Homo sapiens, vertical occipital, the
upper scale, canine fossa, the most important part is developed. And the torus, is still thick. It shows a little bit of differentiation, but still the lateral part is very thick. It’s a mosaic evolution
that we see in these groups. What about LH 18 Ngaloba,
again from Tanzania, from the Ngaloba beds. The age, Hay (1987) reported
age of the fossil for LH 18 in the marker tuff, probably
greater than 128, 29,000 to greater 132,000. Certainly less than 990,000. Millard (2008) reported
an age less than 490,000. Now you can see how messy the dating is. My assumption is an age of 400,000. This is just an assumption. Maybe, an age of 400,000
may be acceptable. Cranial capacity, 1367,
it’s big cranial capacity. Occipital, you can see
the back of the skull, open with no torus. That is also an advanced feature. Post-canine fossa is visible, like the one I showed you in Ndutu, it has a post-canine
fossa, which also presents in modern Homo sapiens like us. Okay, what about Florisbad
from South Africa? Based on ESR dates, the age best estimate is 329 to about 189,000 years. See Millard in 2008. Has a canine fossa, look at this. This depression is called a canine fossa. Short face, typical for Homo sapiens. But the earlier forms,
especially like Ngaloba, the face is still big, even
though it has canine fossa. That means (alarm rings),
everything did not come together. Everything did not come together. Okay, the frontal is very
steep, has developed frontal, steep frontal, a forehead. The anterior surface of the
zygomatic forms 90 degrees. This one is 90 degrees. That is typical Homo sapien. What about Jebel Irhod? Long and low cranium,
continuously thick browridge, these are primitive morphologies. Cranial capacity is 1450 cc. That’s more than average,
even for modern humans. (laughter) Okay, convex frontal, but still low, convex frontal, still low. Browridge is thick mediolaterally,
which is very primitive. Occipital moderately angled. Short face. The anterior surface of the zygomatic forms 90 degrees, which
is typical Homo sapiens. The dates of Jebel Irhod evolved from, it’s an evolution of
dates, now you can see. When it was first published,
it was 40,000 years old, 1968. Then 160,000 in 1991. And 300,000, 2017. This is an evolution of dates. I suggest to redate other sites
like Florisbad and others. For whatever worth it may be. If we redate, they may also
evolve in that direction. What about Omo? The Omo Kibish skulls, there are two different kinds of skull. This is Omo One, and this one is Omo Two. Omo One is very advanced,
typical Homo sapiens, Steep frontal, occipital
morphology, very Homo sapiens-like. Omo Two is very archaic in
occipital and frontal profile. They may not belong to the same group of evolutionary status. Omo Two is less advanced, and may belong to ancestral lineage of Omo One. It may belong to a different
contemporary populations. It may, if they are from the same horizon. Based on taphonomic evidence, they may not be contemporaries. Even though they are published
to be as contemporaries, for interpretation, it’s misleading. If we can confirm it, it’s an evidence by itself
for two different populations, one advanced population, the
other, primitive population, to live side by side. But based on our observation,
Omo Two is very primitive. You can see. It’s an isolated surface find. No associated archeology like Omo One. Cranium is low and massive, very low. You can see the front is very flat. And occipital is very
flexed, unlike Omo One. Frontal is low, weakly keeled,
a strongly angled occipital. Cranial capacity is very big,
typical Homo sapiens type. Broad, unconstructed frontal. Parietal is bulged and expanded. And it was a surface find, not associated with strong tools. So we think, based on this evidence that we observed on the fossil, note the polished, eroded supraorbitals. They are polished and eroded. And the polish is also
on the temporal surface. This is at highly polished. So these features may suggest
hydraulic transportation of the skull by paleo-Omo
River or its tributaries. So I think they are not contemporaries. And this is very good information to take into consideration. Herto, let’s see. Small face, tacked under the brain case. Small face, tacked under the brain case. Non-projecting midface,
the midface not projecting. It’s only the lower part of the face looks a little bit projection. It’s a very, you know, kind
of primitive character. Anterior surface of the zygomatic, this area forms a vertical orientation. This vertical orientation,
typical with Homo sapiens. Has a post-canine fossa, that is something of
the Ndutu and Florisbad and Jerbal Irhad, okay? Inferior border of
zygomatic joins 90 degrees, typical of Homo sapiens. A steep frontal, that is major mark of Homo
sapiens, steep frontal. Browridge differentiated
into medial and lateral. The lateral part is thin and
the medial part is thick. It’s typical of Homo sapiens. Occipital is open and flexed. Long vault, but still has
some primitive characters. So what do we learn from
the Middle Pleistocene fossil record in Africa? The Homo sapiens lineage emerged early, maybe by 500,000 years ago. And earlier groups between 500,000 and one million
years ago, Daka and Buya between those times, may represent the last common ancestor
with the Neanderthals. The changes observed through time includes brain expansion, that we
have seen from Saldanha time, parietal bulging, that we
observed also Saldanha time, occipital less flexed,
that is that we have seen in at least by Broken Hill. Facial profile advanced and smaller, that is what we see next by Ndutu time. Brain getting bigger and frontal keeps, frontal convex but still low. That is what we see in Jerbal Irhad. Browridge reducing, occipital more open. Steep frontal, smaller face, that is the third stage that we have seen. This is what we see in idaltu and still with some primitive features. Then, where do we go? The first stage, there’s one stage, that’s the brain expansion
that we have started in the earlier parts. And the second stage, then we have seen a little
bit of facial change, like the first emergence
of the facial morphology developing post-canine fossa. And the third stage, superior expansion and lateral part of
the browridge thinning. This is a sequence that
we have seen through time. Then at which stage of the lineage do we claim the earliest
Homo sapiens status for a hominid? It’s unfortunate, we use that terminology. And I think it is misleading. So it is an arbitrary term
that we use, the earliest. And the easiest thing to do is we find a Homo sapiens at 160,000. We find a Homo sapiens at 400,000, but the earliest is a
misleading terminology, I think. Thank you very much. (applause) (dramatic music)

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5 thoughts on “The Perspective from Africa – Berhane Asfaw: Assessing Claims for the “Earliest” Homo sapiens

  1. Because we know about time and numbers we think we know sooo much … BUT …. we can’t see 25 million years for what it is . The expanse of time is so great that we can’t really understand . Our minds concentrate and focus on relative time . That I believe is why people think we were made and not evolved . Like the commenter on my comment below . It’s hard to look back down the tunnel of time depending on IQ you may never really fully understand

  2. A very interesting talk. It is worth reading the paper of Lacruz et al that he mentions, “The Evolutionary History of the Human Face,” for more nice images of skulls. It also discusses a mechanism for the differentiation of facial morphology, bone deposition and resorption. I expect that new insights from evo-devo will soon give more insight into the lineages involved in early and late sapienization.

  3. Great talk! It seems indisputable that different lineages of hominids, showing archaic and modern human characteristics, evolved alongside in Africa.

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