Apes, Apeman and Man

1
Apes, Apeman and Man

• Lee Spencer, Ph.D.
• Earth History Research Center
• Southwestern Adventist University
• Keene, TX 76059

2
Definitions

• Science is the process of formulating testable
  (i.e. reject able) hypotheses.
• Faith is the acceptance of statements,
  interpretations and/or hypotheses in spite of the
  lack of data or data that appears to contradict
  the statements, interpretations and/or
  hypotheses.
• Cosmology is the belief system explaining the
  cause for the underlying harmony in the universe.
  Examples of cosmologies include naturalism where
  natural law is self-existent and is the sole
  cause for the underlying harmony of the universe
  and variations of supernaturalism where there is
  a being above natural law.

3
Definitions (Continued)

• Creation, Evolution, Diluvialism are all
  cosmologies because they cannot be falsified
• Evolutionary senarios such as phylogenetic
  hypotheses are falsifiable and therefore
  scientific.
• Evolution cannot be falsified because even if all
  phylogenetic hypotheses are falsified, ad hoc
  statements will be invoked to prevent the
  cosmology from being falsified (such as the
  incompleteness of the fossil record)

4
Definitions (Continued)

• Supernaturalistic cosmologies include theistic
  evolution, progressive creation, and
  neodiluvialism (usually called young-earth
  creation)
• Theistic evolution is indistinguishable from
  naturalistic evolution in practice, it just
  assumes that God directed evolution

5
Definitions (Continued)

• Progressive creation proposes that God had many
  creative episodes and that the event that
  produced man is just the latest
• Neodiluvialism proposes that there was a single
  event for the creation of life a few thousand
  years ago and the geological column was produced
  by Noahs Flood

6
The Origin of Man

• The origin of man is one of the most intensely
  debated part of the whole controversy
• Beliefs on mans origin differ tremendously
  throughout the world

7
Belief Systems on Origin of Man

• For millennia, the predominately held belief was
  that man was designed and created by a
  supernatural being God
• Starting about 150 years ago, there was a shift
  to naturalism with the process called evolution
  by natural selection
• Next, compromise views like theistic evolution
  and progressive creation developed

8
Christian Beliefs on Human Origin

• The Pope recently announced that theistic
  evolution is the official church position for
  Roman Catholics
• The Baptist and Adventist position is a
  young-earth creation/ neodiluvial model
• Other denominations vary greatly in the official
  stance on the origin of man

9
Data, Interpretation and Hypothesis Testing

• First we will summarize the data relating to the
  origin of man
• Then we will examine the evolution/theistic
  evolution, progressive creation, and young- earth
  creation hypotheses and test them to the data

10
Hominoids, the Apes and Man

• Linnean classification places the apes and man
  together in the superfamily Hominoidea
• There are 3 families
• Hylobatidae (gibbons)
• Pongidae (Chimps, Gorilla, and Orangutan)
• Hominidae (Man)

• All are tailless large primates
• The Families are separated by different modes of
  locomotion

11
Family Hylobatidae the Gibbons

• The gibbon are all brachiators which mean the
  move through the forest canopy by swinging arm
  movements with the body suspended beneath the
  arms
• Also called the lesser apes

12
Family Pongidae the Great Apes

• The Pongidea include the chimpanzees, gorillas
  and orangutans
• All are knuckle-walkers which means that when on
  the ground, they perambulate quadrapedally

• The orang makes a fist and the first phalanx
  makes ground contact
• The chimps and gorilla make ground contact with
  the second phalanx

13
Family Hominidae Man

• Humans are the only living primates that are
  habitually bipedal

14
The Pongid Skull

• In the figure to the left is pictured an adult
  male gorilla skull. It can be characterized as
  having a prominent saggital crest (ridge along
  the top of the skull), a large bony orbit (eye
  socket), and a prominent brow ridge. It also has
  a large flat facial area below the orbits and a
  protruding muzzle (prognathism) with large canine
  teeth.

15
The Modern Human Skull

• Compared to the gorilla skull, the human skull
  lacks a saggital crest, has gracile orbits
  (thinner and smaller), and a short face, with no
  prognathism.

16
Fossil Hominids

• In the fossil record there are three major groups
  of bipedal primates intermediate in morphology
  between the pongids and modern man

17

• There is a gradational increase in cranial volume

18
1. Chimpanzee 2. Australopithecus africanus 3.
Homo habilis 4. Kenyanthropus rudolfensis 5-6.
Pithecanthropus erectus 7-8. P. saldensis 9.
Homo heidelburgensis 10-11. H. neanderthalensis
12. H. sapiens

• When viewed from the top, all of the skulls
  except that of anatomically modern man show a
  marked constriction just behind the orbital
  region. This constriction imparts a decide
  pear-shape to the braincase. Because the skull of
  anatomically modern man is inflated in the
  frontal area and has gracile orbits, the overall
  shape of the skull is more ovoid than pear-shaped

19
1. Pan sp. (chimpanzee), 2. Australopithecus
africanus, 3. Pithecanthropus erectus, 4. Homo
heidelbergensis, 5. Homo neanderthalensis 6.
Anatomically Modern Man

• We also see a gradation of cranial morphologies
  from an essentially pongid morphology to the
  modern human morphology. Large, bony eye sockets,
  a large nasal opening, and stout facial bones
  dominate the face of the pongid. The pongid
  facial pattern is seen in all fossil hominids
  except anatomically modern man.

20
Chimpanzee Neanderthal Modern Man

• A similar pattern is seen in lateral view. The
  pongid skull is characterized by a sulcus behind
  the brow ridges, prognathism and a protruding
  occipital region. Anatomically modern man lacks
  prognathism and brow ridges with the accompanying
  sulcus, and has a much less pronounced occipital
  bulge. The fossil hominids show the pongid
  pattern, including the Neanderthal whose
  endocranial volume averages more than
  anatomically modern man.

21

• Another character that is unique to anatomically
  modern man is the parietal bulge. When viewed
  from behind, the widest point of the skull of
  anatomically modern man is high, in the parietal
  region. The widest point of the pongid skull is
  close to the base of the skull, near the auditory
  region. All of the fossil hominids, including
  Neanderthal, have the widest point low near the
  auditory.

22
1. Chimpanzee 2. Australopithecus africanus 3.
Pithecanthropus erectus 4. Homo sapiens

• In the pongids, the foramen magnum is located
  near the back if the skull so the head can be
  inclined and pointed forward during quadrapedal
  locomotion (knuckle-walking). In anatomically
  modern man, the foramen magnum is under the skull
  since the skull weight is born by the shoulders
  while walking upright. The fossil hominids show
  intermediate placement of the foramen magnum
  between that seen in pongids and anatomically
  modern man.

23
1. Australopithecus africanus 2. Homo habilis
3. Pithecanthropus erectus 4. Homo
heidelbergensis 5. Homo neanderthalensis

• The pongid palate is rectangular with the widest
  part at the canines then narrowing backward into
  the skull. The human palate forms a parabolic
  curve with the widest part interior into the
  skull.

Fossil hominids are intermediate in palate shape
between the pongid and human morphologies. In all
of the species except anatomically modern man,
the premolars and molars form a relatively
straight line. The axis of the line shifts from
nearly parallel with the midline of the palate in
the australopithecines to broadly divergent in
the Neanderthals.
24
(No Transcript)
25

• Humerofemoral index is a ration of the length of
  the humerous divided by the length of the femor

Arboreal apes have longer arms than legs while
modern humans have shorter arms than legs. The
humerofemoral index quantifies this difference.
If the limbs are of equal length, the index will
be 100. Values greater than 100 occur when the
arms are longer than the legs, values less than
100 occur when the arms are shorter than the
legs. The australopithecines plot intermediately
between the pongids and humans. The
pithecanthropines and Homo species all plot
together with the arms shorter than the legs.
26

• The australopithecines also plot with the apes on
  the orientation of the scapula, an adaptation for
  arboriality. If a line is drawn through the axis
  of the ventral bar on the scapula and another
  through the glenoid cavity, the intersecting
  angle can be measured. The apes have a
  bar-glenoid angle less than 140 degrees while
  humans have an angle of approximately 145
  degrees. The australopithecines have an angle
  about 130 degrees. Like the humerofemoral index,
  the pithecanthropines and Homo plot together.

27
Another index of arboriality is the relative
length and degree of curvature of the phalanges
(fingers and toes). The phalanges of the pongids
are relatively long and curved those of modern
man are short and straight.

• The australopithecines are short like modern man,
  but curved like the pongids. The degree of
  curvature can actually be calculated and
  quantitatively compared among the various
  hominoids (Susman et al. 1984). The numbers
  confirm what was intuitively obvious from the
  illustrationthe australopithecine phalanges have
  a pongid curvature. Members of the Homininae all
  have relatively straight phalanges.

28
(No Transcript)
29
(No Transcript)
30
Summary of Characters