If you're saying that when you look at the skeletons of the early Hominoids (for example), that you can not actually visually distinguish ANY gradual transitions (a.k.a. Evolution) of skulls from 18 mya (million years ago) towards the skulls of Homo Sapiens.
Ok. …. I would like to show you skeletal evidence of gradual transitions (Evolution) of hominoids during the past 18 million years. To make things easier to visualize, I will just show you the skulls of hominoids. (I compiled all the stuff I'm about to show you from a number of different Web sites. This post is not a compilation of large sections from any one site.)
BEFORE I do that, it is IMPORTANT to look at and understand a “Tree” of the showing the Phylogenetic relationships of hominoid species that did and did not lead toward Homo Sapiens. If you are not familiar with that Tree, you will not be able to differentiate which URLs, depict skulls of species that lead toward the evolution of Homo Sapiens. Several species simply became extinct, and did not lead toward Homo Sapiens.
Evolutionary Phylogenetic Relationships (Tree) of Hominids
http://www.mnh.si.edu/anthro/humanorigins/ha/a_tree.html and (Tree)
http://www.mnh.si.edu/anthro/humanorigins/ha/alt_tree2.html and (alternate for a portion of Tree above)
http://www.mnh.si.edu/anthro/humanorigins/ha/africomp.html and (for further info)
http://www.mnh.si.edu/anthro/humanorigins/ha/robust.html (for further info).
I will begin with showing you a single Web pages that contains pictures of ONLY SOME OF THE KNOWN extinct hominoid species skulls. NOT ALL of the skulls shown on the Web page below, actually lead towards the Evolution of Homo Sapiens. Note also that, NOT ALL species of known mostly extinct hominoids are shown on the Web pages below! SEVERAL extinct hominoid species are NOT SHOWN on the Web page below, BUT WILL BE SHOWN on individual Web pages referenced further down in this post.
Front View:
http://www.amonline.net.au/human_evolution...kulls_front.htmSide View:
http://www.amonline.net.au/human_evolution...skulls_side.htmBottom View:
http://www.amonline.net.au/human_evolution...ulls_bottom.htmTop View:
http://www.amonline.net.au/human_evolution.../skulls_top.htmVirtual View:
http://www.amonline.net.au/human_evolution...kulls/index.htmBELOW IS AN almost COMPLETE LIST (as of 2/25/04), WITH URL’s to PICTURES OF SKULLS of known extinct hominid species (in chronological order from oldest to most recent) beginning 17-18 million years ago (mya) and progressing to the present time. A few species were omitted, but fossils for them can be found at:
http://www.talkorigins.org/faqs/homs/typespec.htmlPlease read the following 5 IMPORTANT NOTES.
NOTE 1: NOT ALL hominoids mentioned below are ancestors of Homo Sapiens. In other words, some of the hominoids listed below did NOT lead toward the evolution of Homo Sapiens.
NOTE2: A number of these species lived side by side, and that some dates overlap in the same, AND in differing locations.
NOTE 3: The details and pictures for the list of hominoids were compiled (by myself) from the following Web Sites (run by reputable institutions):
http://artemis.austincollege.edu/acad/bio/....evolution.html and
http://www.amonline.net.au/human_evolution/skulls and
http://www.mnh.si.edu/anthro/humanorigins/ha/a_tree.html and
http://www.talkorigins.orgNOTE 4: The evolution toward modern day monkeys, apes, and old world monkeys
is not depicted.
NOTE 5: SOME INTERESTING AND INFORMATIVE additional information is provided below for each of the species. Note also that, where tool making is mentioned, it indicates tools were found
beside the skeleton(s).
NOTE: 6: A few species were omitted, but fossils for them can be found at:
http://www.talkorigins.org/faqs/homs/typespec.html=====================================================
=====================================================
A brief Anthology of Hominoids From 17-18 million years ago (mya), with
URL’s to a Skull of each Species
==========================================================================================================
Species: Proconsul Heseloni
Skull:
http://www.amonline.net.au/human_evolution...s/proconsul.htmSpecies: Proconsul Africanus
Skull:
http://www.toyen.uio.no/palmus/galleri/mon...nglish/x527.htmNOTE: 1 additional Proconsul species existed, but I don’t have pictures for it.
(Walker et al 1983, Nature 305:525-527)
• 18-17 mya
• Kenya
• skull, forelimb, hand, foot; 800 fossils exist; 9 complete skulls; skeletons from babies to adults
• quadrapedal
• brain size 154-181 cm3
• extreme protruding jaw
• 2 additional Proconsul types existed and varied in size from each other.
Species: Kenyapithecus (a.k.a. Kenyanthropus platyops )
Skull:
http://www.modernhumanorigins.com/wt40000.html(McCrossin and Benefit 1993, PNAS 90:1962-1966)
• 14 mya
• teeth, skull, arm, foot bones
• 36 kg.
• thick enamel
• could move arms above head; ancestor to Gorilla, Pan, Homo
Species: Otavipithecus namibiensis
Skull:
AND
BOTH identified on Web Page:
http://www.ivry.cnrs.fr/deh/gommery/gommery.htm(Conroy et al 1992, Nature 356:144-148)
• 13 mya
• Namibia
• jaw fragments and mandible
• thin enamel
• weighed 14-20 kg.
• lived 10 years
Species: Dryopithecus laetanus
Skull:
Jpg used on Web Page:
http://webs.sinectis.com.ar/mcagliani/dryopith.htmJaw:
http://fossils.valdosta.edu/fossil_pages/f...ls_ter/p16.html (Moya-Sola and Kohler 1996, Nature 370:156-159)
• 9.5 mya
• Europe
• powerful arms with wide range of motion, large hands, short legs
• possibly related to Pongo or African Great Apes
Species: Oreopithecus bambolii
Skeleton:
http://www.toyen.uio.no/palmus/galleri/mon...nglish/x616.htm(Kohler and Moya-Sola 1997, PNAS 94:1747-1750)
• 9-7 mya
• Italy
• believed to be bipedalback arches forward, knee is vertically aligned, big toe extends out 90 making movement slow
Species: Sivapithecus indicus
Skull:
http://www.amonline.net.au/human_evolution...ivapithecus.htm10 - 7 mya approximately
Northern Pakistan, north-west India
Species: Orrorin tugenensis
Bone Fragments:
http://www.modernhumanorigins.com/lukeino.html6.2-5.65 myr
North Africa
bipedalism is not particularly clear
Species: Ardipithecus ramidus
Skull:
http://www.modernhumanorigins.com/ara-vp-1-129.html http://www.msu.edu/~heslipst/contents/ANP440/ramidus.htm(White et al 1994, Nature 371:306-312)
• 5-4 mya
• Ethiopia
• shares hominid features such as: v-shaped canines, large molars, incisors, and premolars
Species: Australopithecus anamensis
Skull:
http://www.modernhumanorigins.com/kp29281.html http://www.modernhumanorigins.com/kp29283.htmlhttp://faculty.vassar.edu/piketay/evolution/KNMKP.htmlAND
http://www.mnh.si.edu/anthro/humanorigins/ha/africomp.html(Leakey et al 1998 Nature 393:62-66; Leakey et al 1995 Nature 376:565-71)
• 4 mya
• Kenya
• skull, two lower jaws, upper jaw, lower face, upper and lower thirds of tibia,
• teeth share characteristics of both chimps and hominids
• share tibia with hominids; share lower jaw with chimps
Species: Australopithecus bahrelghazali
Jaw:
http://www.modernhumanorigins.com/kt12-h1.html3.0 and 3.5 mya
Chad, Africa
Species: Australopithecus afarensis
Skull:
http://www.amonline.net.au/human_evolution...a_afarensis.htm AND
http://www.mnh.si.edu/anthro/humanorigins/ha/africomp.html(Kimbel et al 1994 Nature 386:449-451)
• 3.5 - 3.0 mya
• Ethiopia
• bipedal, massive skull, large canines, long toes, long forearms, looked like chimpanzee
• brain size 1/3 modern human
• both large and small bones found; sexual dimorphism?
• most likely ancestor is Australopithecus anamensis
Species: Australopithecus africanus
Skull:
http://www.amonline.net.au/human_evolution...a_africanus.htm http://www.modernhumanorigins.com/taung.html AND
http://www.mnh.si.edu/anthro/humanorigins/ha/afri.html(Clark and Tobias, 1995 Science 269:521-524)
• 2.8 - 2.3 mya
• South Africa
• smaller canines, less projecting muzzle,
• brain size 525 cm3
• sometimes bipedal, sometimes arboreal…possibly two species?
• not descendant of Australopithecus afarensis
Species: Australopithecus garhi
Skull:
http://www.modernhumanorigins.com/bou-vp-12-130.html2.5 mya
Central Africa
Species: Paranthropus aethiopicus
Skull:
http://www.mnh.si.edu/anthro/humanorigins/ha/aeth.htmlhttp://www.modernhumanorigins.com/wt17000.html2.5 - 2.7mya
East Africa
Species: Paranthropus boisei (formerly australopithecus boisei)
Skull:
http://www.amonline.net.au/human_evolution...ls/p_boisei.htmhttp://www.modernhumanorigins.com/oh5.htmlEastern Africa
2.3 - 1.2 mya
Cranial capacity : 450 - 550cc
These hominids may have used stone tools
Species: Paranthropus robustus
Skull:
http://www.mnh.si.edu/anthro/humanorigins/ha/rob.htmhttp://www.modernhumanorigins.com/sk48.html(Susman 1988 Science 240:781-784)
• 2 – 1.2 mya
• opposable thumb, small brain, large teeth
No tool use
Species: Homo rudolfensis
Skull:
http://www.amonline.net.au/human_evolution...rudolfensis.htmEastern Africa
2.4 - 1.9 mya
Cranial capacity : 750 - ca 800cc
There is some evidence that Homo rudolfensis made and used stone tools
Species: Homo habilis was a different species that lived alongside Homo rudolfensis.
Skull:
http://www.mnh.si.edu/anthro/humanorigins/ha/hab.htmlEastern Africa
2.4 - 1.9 mya
cranial capacity of 680cc
Species: Homo georgicus
Skull:
http://www.talkorigins.org/faqs/homs/d2700.htmlDiscovered in 2001 at Dmanisi in Georgia.
Estimated age is 1.8 million years.
It consisted of a mostly complete skull, including a lower jaw (D2735) belonging to the same individual. (Vekua et al. 2002, Balter and Gibbons 2002)
At around 600 cc, this is the smallest and most primitive hominid skull ever discovered outside of Africa. This skull and two others discovered nearby form a near-perfect transition between H. habilis and ergaster.
Species: Homo ergaster
(formerly referred to as Homo erectus "Java Man", which is a species confined to eastern Asia)
Skull:
http://www.amonline.net.au/human_evolution.../h_ergaster.htmhttp://www.modernhumanorigins.com/er3733.html• 1.8 - 1.5 mya
• found in Africa
Cranial capacity : 800 - 850cc
• bipedal
• low, broad, elongated skull…heavy facial architecture
• post-cranial skeleton identical to modern humans
• evidence of coexistence with Homo sapiens for several thousand years
• fire (hearth), hand axes, stone flakes,
These hominids may have been hunters and made and used purpose-specific stone tools
Species: Homo antecessor
Skull:
http://www.modernhumanorigins.com/grandolina.html• 800,000 — 780,000 ya
• 80 fossils found in Spain: ribs, vertebrae, radius, patella, teeth, mandible
• bipedal…
• shared facial characteristics of modern Homo sapiens smaller canines, projecting nose and midface, sunken cheekbones
• also shared ancestral facial characteristics: prominent brow ridge, multiple roots for premolars
• simple tools found…used to scrape meat off bones
• believed to be last common ancestor to both modern humans and Neanderthal
Species: Homo erectus (sometimes now referred to as Homo pekinensis “Peking man”)
Skull:
http://www.amonline.net.au/human_evolution...s/h_erectus.htmSkull (& Body):
http://www.modernhumanorigins.com/wt15000.htmlEastern Asia
0.5 - 0.3 mya in China, 1.0 - ca.0.3 mya in Java
500,000 - 300,000 ya
Cranial capacity: 1,043cc
These hominids were hunters, made and used purpose-specific stone tools and are credited with early use of fire
Species: Homo sapiens heidelbergensis
Skull:
http://www.amonline.net.au/human_evolution...elbergensis.htm• 300,000 - 200,000 ya
• Throughout old world
Cranial capacity: 1,300cc
• heavy architecture…thick brow ridge…resembles Neanderthal
• These hominids made and used highly modified stone tools, practised co-operative hunting, may have had limited language skills and religious beliefs and may have cared for the aged and weak
Species: Homo sapiens neanderthalensis
Skull:
http://www.amonline.net.au/human_evolution...erthalensis.htm(Krings et al 1997, Cell 90:19-30)
Europe and western Asia…glacial conditions
• 300,000 - 30,000 ya
Cranial capacity: 1200 - 1750cc
• most bones of 32 individuals found in Spain; 13 individuals found in France; hyoid bone found in Israel suggesting sophisticated speech
• evolved from Homo erectus of Europe
• believed to have coexisted with Cro-Magnon
• tools, burial, care of ill, intelligent behavior,
• separate branch from Homo sapiens
• short, stocky, big faces, large front teeth
These hominids lived at a similar time as Homo erectus but in a different part of the world. They made and used highly modified stone tools, practised co-operative hunting, had limited language skills and religious beliefs and cared for the aged and weak
Species: Homo sapiens sapiens (Cro-Magnon)
Skull:
http://www.mnh.si.edu/anthro/humanorigins/ha/cromagnon.html• 120,000 ya
• Africa, Middle East, France, Spain,
• sophisticated tool kit
• advanced artwork: decorated tools, beads, ivory carvings, musical instruments, cave paintings,
• not ancestor of Neanderthal; shared common ancestor; may have coexisted or existed separately
• speech, cleanliness, burial (symbolic thought),
• physically identical to modern humans…same brain size
Species: Homo sapiens sapiens -- Anatomically modern humans
Skull:
http://www.amonline.net.au/human_evolution...s/h_sapiens.htm(Nei, 1995 PNAS 92:6720-2)
• Single African Origin Theory 125,000 ya
• divergence of the races 100,000 ya
• Theory of Alternative Regional Community races evolved independently under separate selection pressures
• brain size = 1400 cm3 = 85.4 in3
• ancestors brain doubled in size over 2,000,000 years
• tools and communication arose 2.5 mya
• religion, art, advanced language arose 40,000 — 30,000 ya
For more information about:
Skulls:
http://www.amonline.net.au/human_evolution...s/more_info.htmhttp://www.modernhumanorigins.com/hominids.htmlAnother Tree of Hominoids:
Human Evolution:
http://www.amonline.net.au/human_evolution/about.htmhttp://www.mnh.si.edu/anthro/humanorigins/ha/a_tree.htmlhttp://www.modernhumanorigins.comhttp://www.talkorigins.org/faqs/homs/specimen.html#ramidusSpecies:: (Current day) Gorilla
Skull:
http://www.amonline.net.au/human_evolution...lls/gorilla.htmAfrica
These primates have the ability to learn & conceptualize
Cranial Capacity: 450 - 600cc