www.sciencemag.org/content/345/6192/1236828/suppl/DC1
Supplementary Materials for
Evolution of Early Homo: An Integrated Biological Perspective
Susan C. Antón, Richard Potts, Leslie C. Aiello
E-mail: susan.anton@nyu.edu (S.C.A.); pottsr@si.edu (R.P.); laiello@wennergren.org (L.C.A.)
Published 4 July 2014, Science 345, 1236828 (2014)
DOI: 10.1126/science.1236828
This PDF file includes:
Supplementary Text
Tables S1 and S2
References
Supplementary Text
Early Homo Groups: Anatomy and Constituents
The main specimens we include in each early Homo group are listed in Table S1.
Group characteristics and ranges of body, brain and dental size can be found in text Table
1 and Box 1. Here we provide additional detail on the specific features used to recognize
and affiliate key fossils to particular groups or to differentiate among groups. For the
purposes of this review we focus on the fossil record from about 2.5 to about 1.5 million
years ago.
Earliest fossil Homo:
Earliest fossil Homo is identified relative to late Australopithecus by reduced
tooth and jaw size and shape and reorganization of the palate. Later early Homo groups
reveal that there are a variety of ways in which this reorganization takes place. In the
case of the early (~2.33 Ma) palate A.L. 666-1 from Hadar, molar size reduction, small
canine root size, a relatively deep palate and posterior dental arches that are broad,
parabolic and not parallel are key features (33).
Time based on East African remains: >2.1 million years ago
1470 group:
Affiliations to the 1470 group start with the face of KNM-ER 1470, which is
anatomically similar to but much larger than the partial face, KNM-ER 62000. The shape
of the palate and arcade of KNM-ER 1470 and KNM-ER 62000 link them to mandible
KNM-ER 60000. Mandibular features and dental proportions link KNM-ER 60000 with
KNM-ER 1482. Arcade shape definitively excludes KNM-ER 1802 and the
morphologically similar Uraha 501, from Malawi, from this group (5).
Facial Shape: The facial skeleton is fairly derived but not specifically in the
direction of later Homo. The anterior face is flat, a feature that is independent of hafting.
Contributing to this flatness, the incisor and canine row is flat/squared-off and the
zygomatic processes arise relatively far forward on the face. The nasals are peaked. The
face is relatively tall, and related to this, the broad mandibular ramus (as represented by
KNM-ER 60000) sits quite high above the tooth row. The mandibular corpus is
relatively tall compared to width and the posterior mandible is much broader
(bigonial/bicondylar) than the anterior in part as a result of diverging posterior tooth
rows. As a result, the extramolar sulcus is broad.
Dentition: Lower incisor crowns are narrow with relatively short roots and the
canine root is also reduced in size compared to Australopithecus. The posterior tooth row
is relatively short due to premolar foreshortening not to molar reduction. Premolars are
relatively mesiodistally compressed and are not unduly molarized, but molars are large.
There is no third molar reduction. While Table 1 may suggest that the 1470 group has
larger molar occlusal areas than the 1813 group, dental size is not absolutely large in the
1470 group with respect to other non-erectus Homo. Apparent difference in molar size is
most likely an artifact of excluding specimens such as KNM-ER 1802, KNM-ER 1590
and OH 16 from both groups in favor of putting them in an unaffiliated non-erectus
category. However, KNM-ER 1802 cannot be placed with the 1470 group and we
2
suspect belongs to the 1813 group (see below). Such placement would obviate most
molar size differences.
Vault: Vault anatomy is preserved only in the largest specimen, KNM-ER 1470
(41). The vault is relatively rounded in sagittal view with a steeply rising frontal lacking
a supratoral gutter. There is moderate postorbital constriction. No sagittal or nuchal
cresting is apparent. Greatest breadth is at the supramastoid crest region, but the vault
walls rise nearly vertical from supramastoid gutter rather than angling medially and thus
greatest parietal breadth is only a bit smaller than greatest breadth.
Size: Both body and brain size estimates in Table 1 are skewed to the larger end of
the assemblage because only the largest specimen, KNM-ER 1470, preserves cranial
capacity and orbit size (from which body mass may be estimated). However, the
fragmentary remains affiliated with one another based on palate shape display a range of
size variation in which KNM-ER 1470 is the largest and KNM-ER 62000 the smallest (at
only about 75-80% of KNM-ER 1470’s size). Estimates of the body and brain size range
of this group suggested by these fragments is, therefore, extensive and overlaps
substantially with the 1813 group (see details in Box 1).
Postcrania: Postcranial traits and proportions are unknown given the current lack
of affiliated postcranial remains.
Time based on East African remains: 2.09-1.78 million years ago
The 1813 group
Affiliations start from the face of 1813, which is anatomically similar to that of
OH 13 and KNM-ER 1805, both of which also retain a mandible. The anterior palate of
1813 also links to the OH 65 palate – however, the latter specimen is substantially larger
with some shape differences and scaling studies may indicate whether these are of
importance when additional specimens are available. Unlike the 1470 group,
mandibular/arcade shape is consistent with that of KNM-ER 1802 and UR 501; however,
because this shape is relatively primitive this consistency does not dictate identity.
Nonetheless, the most parsimonious explanation would be that there are two groups of
non-erectus early Homo and that KNM-ER 1802 and Uraha 501 affiliate with the 1813
group.
Facial Shape: The facial skeleton is fairly primitive and relatively prognathic
compared to the 1470 group. The anterior palate is rounded and more projecting (the
incisors and canines do not form a flat row across the front of the palate) and the
posterior tooth rows are more parallel (less diverging) and relatively narrow (5).
However, the face lacks features seen in the face of Australopithecus including facial
pillars and a glabellar prominence and while more prognathic than the 1470 group is less
so than Australopithecus (41). Additionally, the nasals are more peaked. The mandibles
of the 1813 group also tend to have corpora that are more similar in their height and
width than the 1470 group, which tends to have fairly tall corpus heights for width.
While no complete rami are present, the partial rami would suggest that the extramolar
sulcus is not as broad and probably that the bicondylar/bicoronoid breadths are not as
great compared to arcade breadth as in the 1470 group, which would also partly follow
from the more parallel and narrow posterior arcades.
Dentition: Anterior dental size is somewhat more primitive than the 1470 group
with larger lower incisor crowns and canine roots. There is no third molar occlusal area
3
reduction. Although Tables 1 and S2 show that some specimens have smaller M1s than
KNM-62000 of the 1470 group, the apparent differences in group means/ranges are likely
an artifact of specimen inclusion (see discussion of KNM-ER 1802 above). Molar and
premolar size is reduced relative to the condition in Australopithecus.
Vault and Base: The vault is rounded in sagittal view with a frontal that shows a
continuous posttoral sulcus. There is moderate postorbital constriction. Cresting is
apparent in some individuals. Greatest breadth is low in the supramastoid region, but the
greatest breadth at the parietals is only marginally smaller. The cranial base is shorter
than in Australopithecus and the mandibular fossa is more derived than that genus, but
both lack the specific traits of H. erectus.
Size: Both body and brain size estimates in Table 1 are skewed to the smaller end
of the assemblage because only the smallest specimens, KNM-ER 1813 and 1805,
preserve capacity and orbit size (from which body mass may be estimated), and because
the associated postcranial remains, OH 62, are also from a small individual. However,
the fragmentary remains affiliated with one another based on extrapolation from KNMER 1813’s anatomy display a range of size variation. OH 65 is the largest and about 15%
larger than the next largest, OH 13. The body and brain size range of this group as
suggested by these fragments should have a larger maximum size than exhibited by the
more complete specimens and overlap substantially with the 1470 group (see details in
Box 1).
Postcrania: Evidence of relatively strong humeral to femoral cross-sectional
properties in OH 62 have been used to argue for a substantial arboreal component to the
locomotor repertoire of this group (134).
Time based on East African remains: 2.09-1.44 million years ago
H. habilis:
Currently, only the type specimen is affiliated with this nomen. On the basis of
dental anatomy, OH 7 can be excluded from H. erectus. However, taphonomic damage
to the mandible renders its arcade shape unknown. As a result, the crushed and distorted
OH 7 mandible cannot be definitively affiliated with either group of early Homo.
Parsimony would suggest that its reconstruction will yield a match to one of the
previously described early Homo groups and that the name, H. habilis, would then apply
to either the 1470 group or the 1813 group.
Size and Postcrania: OH 7 preserves two parietals from which a loose estimate of
cranial capacity is 680 cc, which is consistent with any of the early Homo groups. The
specimen also retains hand elements that cannot be presently compared with either group
but which have been used to infer that the individual retained a significant amount of
arboreal behavior in its locomotor repertoire. These inferences differ from those for H.
erectus and are consistent with those made for the 1813 group (134), although they may
also be consistent with the 1470 group, for which we lack positively affiliated postcranial
remains.
Time based on OH 7: 1.84 million years ago.
Unaffiliated non-erectus early Homo:
A number of specimens that can be assigned to Homo on the basis of various
craniodental features, lack the specific arcade anatomy to be definitively assigned to one
4
or the other non-erectus Homo group. As noted above, these include some specimens
that we consider likely to be affiliated with the 1813 group, such as KNM-ER 1802 and
Uraha 501. These also include specimens for which we make no prediction due to
missing anatomy, such as OH 16 (which has relatively narrow lower incisors but does not
retain palatal or mandibular structures and has a relatively large canine root) and KNMER 1590 and 3732 – both of which have relatively large vaults (and in the case of 1590
also maxillary teeth), but which lack palatal or other facial anatomy to affiliate them
definitively. It should be noted that the inferior face of KNM-ER 3732 may be plastically
distorted. The exclusion of these three from both groups substantially influences our
understanding of molar size in the groups as well as cranial capacity.
Postcrania: A number of isolated postcranial limb elements cannot be affiliated with
any certainty to either of the non-erectus Homo groups. In the past the large size of some
of these has been used to argue for their inclusion with the large cranium KNM-ER 1470
– however, this seems unwarranted given the great size overlap present in the facial
remains of both groups.
Early H. erectus:
Affiliations start from the type specimen for the species, Trinil 2, and work
outward from this to other Asian and African specimens, including the Dmanisi remains.
Substantial size variation exists within and across regions, with Dmanisi being the
smallest population known to date. Given the time period of interest to this review, we
have focused on the early African and Georgian remains, as detailed in the text and
tables.
Face: The face lacks the derived anatomy of the 1470 group being less tall and
lacking the squared off anterior palate. The rounded anterior palate and large incisors are
more similar to the 1813 group; however, H. erectus has a more derived, broader and
parabolic arcade. Bigonial/bicondylar breadth, is not as great as in the 1470 group. The
mandible is more gracile than in the 1813 group and has a narrow extramolar sulcus
unlike the 1470 group. The ramus is probably not as tall as in the 1470 group.
Dentition: Canines are more reduced than in Australopithecus or the 1813 group
as are the premolars (but the premolars are not narrow as in the 1470 group), and unlike
both groups of non-erectus Homo, H. erectus shows third molar occlusal area reduction.
Molar cusp apex position is also placed closer to the outer margin of the tooth.
Vault and Base: The vault is more angular in sagittal and posterior view than nonerectus Homo due in part to a series of variably expressed cranial superstructures (e.g.,
bregmatic and sagittal keeling, angular and occipital tori, and supraorbital tori). Some of
these scale with overall cranial size (as proxied by endocranial volume). A continuous
supraorbital torus and posttoral sulcus are present or incipient and a frontal trigone is
often present. There is moderate postorbital constriction. Greatest breadth is low in the
supramastoid region, and the posterior view is heptangular rather than rounded. The
mandibular fossa is relatively less mediolaterally elongated, the cranial base is more
flexed, and there is angulation between the petrous temporal and tympanic not currently
known in early non-erectus Homo.
Postcrania: Substantial portions of the postcranial skeleton are known for two
African individuals with cranial affiliations to H. erectus, the subadult KNM-WT 15000
and the adult KNM-ER 1808. Both are relatively large individuals. Postcranial remains
5
of non-african H. erectus are known from Java, China and Georgia. These reveal
regional variation is size and perhaps body proportions that follow general ecogeographic
patterns. They also suggest a unique antero-posterior flattening and mediolateral
broadening of the proximal femora, which may relate to use. Cross-sectional proportions
suggest that H. erectus humeri are relatively less strong compared to their femora than is
the case in the 1813 group (133), perhaps reflecting the loss of a substantial arboreal
locomotor component to their behavior.
Time based on East African remains: 1.89-0.90 million years ago
6
Table S1: Main fossil specimens attributed to earliest or early Homo by species group in this paper. Most isolated teeth, mandible
fragments, postcranial fragments and specimens younger than 1.5 Ma are omitted.
> 2.1 Ma
Non-erectus Homo
UR-501a
A.L. 666-1
KNM-WT 42718
1470 Group
Craniodental
KNM-ER 1470
KNM-ER 1482
KNM-ER 1801
KNM-ER 60000
KNM-ER 62000
KNM-ER 62003
Postcranial
None
East Africa
Equivocal
KNM-BC 1
1813 Group
East Africa
H. habilis
South Africa
Equivocal
Sts 19
Stw 151
2.1 to 1.5 Ma
Unattributed Nonerectus Homo
H. erectus
South Africa
Non-erectus Homo aff. H. erectus
KNM-ER 1501
KNM-ER 1813
KNM-ER 1805
KNM-ER 3735
KNM-ER 42703b
OH 13
OH 24
OH 62
OH 65
OH 7
KNM-ER 1590
KNM-ER 3732
KNM-ER 3891
KNM-ER 819
KNM-ER 1483
KNM-ER 1802
OH 16
KNM-ER 730
KNM-ER 820
KNM-ER 992
KNM-ER 1808
KNM-ER 3733
KNM-ER 3883
KNM-ER 42700
KNM-WT 15000
OH 9 b
OH 12b
Daka b
KGA 10-1 b
?Stw-53c
Stw-80
SK 27
SK-847
SK-15b
SK-45
OH 62
KNM-ER 3735
OH 7
OH 8
KNM-ER 1472
KNM-ER 1481
KNM-ER 3228
KNM-WT 15000
KNM-ER 1808
None
None
a – may be younger than 2.0 Ma
b – is or may be younger than 1.5 Ma
c – may be older than 2.0 Ma
7
Table S2: Details of comparative brain, tooth, and body size of Australopithecus and Homo. These data are the basis for text Table 1.
A. sediba
(S. Africa)
A. africanus
(S. Africa)
A. afarensisa
(E. Africa)
1470 groupb
(E. Africa)
1813 groupb
(E. Africa)
420 (MH 1)
571 (Stw 505)
485 (Sts 5)
443 (MLD 37/38)
385 (Sts 60)
410 (Sts 71)
550 (444-2)
485 (333-45)
400 (162-28)
750 (1470)
510 (1813)
580 (1805)
595 (OH 24)
660 (OH 13)
420
454-461 (15.9)
478 (15.7)
--
6.9 (MH1)
8.7 (MLD 43)
6.5 (MLD 6+23)
8.4 (Sts 24)
8.16 (Sts 52)
Mean (CV)
--
8.0 (12.5)
7.1 (198-17ab)
8.4 (200-1a)
8.1 (293-3)
8.6 (333x-20)
8.6 (333x-4)
9.7 (444-2)
8.4 (486-1)
8.4 (LH3)
8.4 (8.5)
I1 labio-lingual, Wood #
--
6.9 (MLD 18)
5.9 (Sts 24)
6.6 (Sts 52b)
-5.1 (MH1)
6.5 (8.1)
7.1 (MLD 11)
7.0 (MLD 23)
6.4 (Sts 24)
7.2 (Sts 52)
7.7 (LH2)
7.6 (333w-58)
7.3 (333w9a,b)
7.5 (4001a)
7.2 (444-2)
6.9 (582-1)
7.4 (4)
7.6 (486-1)
6.7 (198-17ab)
7.3 (200-1a)
8.1 (249-26)
8.2 (333x-2)
6.6 (417-1d)
7.6 (481-1)
7.8 (LH 3)
Brain size cc
(specimen #)c
Mean (CV)
Dental size
(specimen #)d
I1 labio-ling, Wood #186
248
Mean (CV)
I2 labio-lingual, Wood
#189
Unattributedb
non-erectus
Homo including
H. habilis
(E. Africa)
630 (OH 16)
680 (OH 7)
1470 group
& 1813 group
&
unattributedb
(E. Africa)
Previous 3
columns
combined
H. aff.
erectus
(S. Africa)
Early H.
erectusb
(E. Africa/
Dmanisi)
-
586 (10.5)
655 (5.4)
629 (12.2)
-
546 (D4500)
638 (D3444)
655 (D2282)
690 (42700)
727 (OH 12)
775 (D2280)
804 (3883)
848 (3733)
909 (WT 15000)
995 (Daka)
1067 (OH 9)
--
8 (OH 65)
8.2 (OH 16)
7.2 (OH 39)
7.7 (1590)
Previous 3
columns
combined
9.4 (15k)
8.2 (OH 29)
7.6 (D2700)
--
--
7.7 (6.5)
7.78 (5.6)
5.4 (60000)
--
6.6 (OH 7)
7.0 (OH 16)
Previous 3
columns
combined
All = 8.4 (10.9)
E. Africa = 8.8 (9.6)
---
-6.1 (1813)
7.3 (OH 65)
6.8 (4.2)
7.0 (A.L. 666-1)
8.2 (808)
8.0 (OH16)
5.8 (OH 6)
6.3 (13.1)
Previous 3
columns
combined
All = 787 (20.2)
E. Africa = 863 (15.9)
6.0 (820)
6.9 (992)
E. Africa = 6.45 (9.9)
8.5 (15k)
8.1 (OH 29)
6.9 (D2700)
8
7.8 (LH 6)
Mean (CV)
--
6.9 (4.9)
7.5 (7.5)
--
6.7 (12.7)
7.2 (15.2)
7.1 (13.8)
I2 labio-lingual, Wood
--
8.2 (MLD 18)
6.9 (Sts 24)
7.9 (Sts 52b)
6.7 (LH2)
8.2 (333w-58)
7.7 (4001a)
8.8 (444-2)
8.7 (437-2)
8.0 (MAK VP ½)
6.6 (60000)
--
7.4 (OH 7)
7.6 (OH 16)
Previous 3
columns
combined
7.0 (820)
7.0 (992)
8.3 (WT 15000)
7.4 (D2738)
Mean (CV)
--
7.7 (8.6)
8.0 (9.6)
--
--
7.5 (1.9)
7.2 (7.3)
1548 (MH1)
1620 (MLD 6+)
1750 (Sts 1)
1690 (Sts 17)
1920 (Sts 21)
1760 (Sts 24)
2030 (Sts 28)
Areas not provided as
the published values
are taken differently
than those for other
taxa
1850 (62000)
1560 (1813)
1770 (1805)
1790 (oh 24)
1640 (oh 13)
1675 (42703)
2010 (OH 16)
2090 (1590)
Previous 3
columns
combined
All = 7.4 (8.2)
E. Africa = 7.4 (10.1)
1560 (D2282)
1700 (D2700)
1490 (WT 15000)
1770 (807)
--
1795 (8.5)
--
1850
1687 (5.6)
2050 (2.8)
1798 (10.1)
1450 (MH1)
1310 (MH2)
1650 (MLD 18)
2070 (MLD 2)
1620 (MLD 40)
1470 (Sts 24)
1666 (Sts 52)
1950 (Sts 9)
1690 (Stw 1)
Areas not provided as
the published values
are taken differently
than those for other
taxa
1460 (60000)
1755 (1482)
1835 (1801)
1500 (OH13)
1880 (OH 16)
1820 (OH 7)
1950 (1802)
1830 (1801)
1920 (UR 501)
1590 (1502)
1410 (OH 37)
1440 (3734)
1610 (1508)
1470 (1507)
1740 (1506A)
1590 (WT 42718)
Previous 3
columns
combined
All = 1630 (7.8)
E. Africa = 1630 (12.1)
1380 (7.2)
1731 (11.9)
--
1683 (11.7)
--
1630 (14.2)
1631 (13.2)
1767 (MH1)
2040 (MLD 6+)
2260 (MLD 9)
2180 (Sts 12)
1960 (Sts 17)
2170 (Sts 22)
2700 (Sts 28)
Areas not provided as
the published values
are taken differently
than those for other
taxa
2016 (62000)
2020 (OH16)
2570 (1590)
[1940] (A.L. 666-1)
Previous 3
columns
combined
--
2218 (11.7)
--
--
1640 (1813)
1730 (1805)
1890(OH24)
1810(OH13)
1833 (42703)
1880 (OH
65)
1797 (5.3)
2177 (15.8)
1933 (13.1)
Areas not provided as
the published values
are taken differently
1790 (60000)
2100 (1482)
1680(OH13)
1840 (1805)
2460 (OH16)
2110 (OH7)
Previous 3
columns
#251
1
M area, Wood #213
Mean (CV)
M1 area,
Wood #289
Mean (CV)
2
M area, Wood #225
Mean (CV)
M2 area, Wood #317
1858 (MH1)
1720 (MH2)
All = 7.83 (10.6)
E. Africa = 8.3 (3.4)
1560 (D211)
1500 (D2738)
1390 (WT 15000)
1370 (992)
1330 (820)
1450 (730)
1780 (806)
1610 (OH 22)
1810 (OH 51)
All = 1533 (11.3)
E. Africa = 1534 (13)
1560 (D2282)
1860 (3733)
1500 (WT 15000)
1560 (1808)
1630 (D2700)
All = 1622 (8.7)
E. Africa = 1640 (11.8)
1420 (D211)
1510(WT 15000)
9
than those for other
taxa
Mean (CV)
1789 (5.5)
2390 (1802)
2730 (UR 501)
2000 (OH 37)
1650 (3734)
2130 (2597)
1900 (1506)
1790 (1507)
combined
1380 (D2738)
1630 (992)
1510 (730)
1990 (806)
All = 1573 (14.1)
E. Africa = 1660 (13.7)
1945 (11.3)
1760 (6.4)
2128 (16.2)
2043 (15.8)
Previous 3
columns
combined
Previous 3
columns
combined
--
Body Mass orbit estimates
--
27/29 (Sts 71)
28/22 (Sts 5)
--
46/51 (1470)
35/31 (1813)
30/36 (OH 24)
--
95% CI Range
Kappelman/Aiello
--
18-38/26-36 (Sts 71)
19-40/19-27 (Sts 5)
--
34-70/43-63
24-50/
22-31(1813)
21-43/
29-42 (OH 24)
--
predicted value by specimen in
kg from Kappelman/Aiello
(specimen #)
Mean of Predicted
values
Kappelman/Aiello RMA
Body Size
Body Mass kg /Femur length
(specimen #)e
(1470)
--
57/58 (3883)
59/65 (3733)
59/-- (WT 15000)
40-58/48-72
(3883)
41–85/54-82
(3733)
--
--/25
--
--
33/34
--
37/36
--
36 (MH 2)
32 (MH 1)
45/434 (Stw 99)
41 (Stw 443)
41 (Stw 311)
38 (Sts 34)
38 (Stw 389)
34 (Stw 25)
33 (Stw 392)
33 (TM 1513)
30 (Stw 102)
30/276 (Sts 13, 34)
28 (Stw 347)
23 (Stw 358)
34 (19)/--
50/382 (333-3)
48 (333x-26)
46/375 (827-1)
45 (KSD-VP-1/1)
43 (333-7)
41 (333-4)
40 (333-w-56)
34 (333-8)
28/281 (288-1)
27 (129a)
--
--/315 (OH 62)
64 (3228)
50/401 (1472)
57/396 (1481)
32 (OH 35)
31 (OH 8)
Previous 3
columns
combined
57 (SK-1896)
53-58(SK 2045)
[30](SKX 10924)
Mean of
33 (9)/-40 (20)/
--44 (31)/
44 (32)/
[43](32)
body mass (CV)/
346 (16)
398 (1)
371 (13)
femur length (CV)
a
A. afarensis specimen numbers are Afar Locality (A.L.) numbers unless otherwise indicated.
b
Numbers without a prefix are KNM-ER numbers. WT numbers are KNM-WT. OH are Olduvai Hominid. D are Dmanisi.
c
Endocranial capacity for: A. sediba (4); A. africanus (121); A. afarensis (122); and individually for Homo following primarily (38) as well as (6, 29, 44, 49).
d
Dental measurement definitions indicated by (41) and these and most data from (38); A. afarensis from (132); A. sediba as above; Newer Homo data not in (41) follow (3, 29, 133).
e
Body mass estimates follow data sources in (8, 21, 58). Femur length CVs are raw values not corrected for dimensionality.
41.5-86/-- (15k)
58/86
68 (736)
63/485 (1808)
54/456 (OH 28)
51/429 (WT 15000)
51/432 (OH 34)
49 (Dmanisi large)
41 (Dmanisi small)
40 (Gona)
All = 52 (20)/450 (9)
E. Africa = 55 (19)/
450 (9)
10
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