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37 Cards in this Set
- Front
- Back
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Define: Brachiation |
the movement in which the suspended body swings between trees by the arms
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which two primates are particularly good brachiators? |
Gibbons and siamangs |
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Which apes are knuckle walkers? |
Gorillas and chimpanzees |
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Which apes are fist walkers |
chimpanzee |
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what are the 4 uses of the upper limb in humans? |
locomotion (infants only) climbing manipulation throwing
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What are the 4 similarities between the ape and human pectoral girdle? |
-apes and humans have equal freedom of movement -the scapular is not fixed in apes or humans -long clavicle acts as a strut for arms -the scapular is positioned dorsally |
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what is the advantage of a dorsally positioned scapula? |
good for: -manipulation -climbing -swimming -throwing |
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similarities of human and ape humerus |
greater and lesser tubercle are positioned well below the humeral head thus allowing upward movement |
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similarities of ape and human glenoid fossa |
-wide, round and flat -lack supraglenoid tubercles which limit upward movement |
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the main difference between human and ape pectoral girdle and shoulder joint |
humans lack strength in extended position |
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list 2 differences in the human and ape clavicle |
-ape clavicle has cranial twist where atlantoclavicularis attaches -ape clavicle is more superiorly oriented at lateral end |
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what is the function of the atlantoclavicularis muscle? |
elevates the clavicle |
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What is the difference between the human and ape supraspinus fossa, what is the significance of this? |
ape supraspinus fossa is larger allowing for a larger suprispinatus |
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what is the difference between the human and ape orientation of the glenoid fossa |
glenoid fossa is oriented more cranially in chimps |
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What are the three differences between the ape and human proximal humerus? |
-ape has deeper bicipital groove -ape has more medially facing head -ape has an attachment for pectoralis abdominis muscle, which humans don't have |
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name this muscle |
Pectoralis abdominis |
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the two major evolutionary changes to the upper limb (broadly speaking) |
-those associated with loss of strength in extended position -those associated with increased ability to manipulate objects |
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What do Ardipithicus' pectoral girdle remains tell us about its method of locomotion? |
-no pectoral girdle remains were found however forearm remains sugest Ardipithicus was arboreal |
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What do Australipithicus afarensis' (Lucy) pectoral girdle remains tell us about its method of locomotion? |
very little clavicle was preserved however scapular and humerei were. Cranially oriented glenoid fossa suggests the upper limb was used in an elevated position. |
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What shape is the head of Australipithicus afarensis' (Lucy) humeral head compared to that of an ape? |
less spherical |
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What is the nature of Paranthropus' humerus? what does this indicate about its method of locomotion? |
-very robust -very powerful muscle attachment sites, especially deltoid indicating arboreal locomotion. |
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what does Australopithicus sediba's pectoral girdle tell us about its locomotion |
cranially oriented glenoid fossa and prounouced attachment for the conoid ligament on the clavicle indicate Australopithicus sediba was aboreal |
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What is the nature of Homo erectus' pectoral girdle |
similar to H. sapiens |
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What is the 'hunting hypothesis' |
the theory that the human pectoral girdle and shoulder joint evolved as it is suited to throwing |
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what 5 characteristics make the human pectoral girdle and shoulder joint suited to throwing? |
-dosally located scapula -humeral torsion -long clavicle -lateral glenoid fossa -storage of elastic energy in the ligaments of the shoulder |
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What effect did the evolution of the modern H. sapiens shoulder have on the lifestyle of humans? |
-better hunters -ate more meat -larger bodies and brains |
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how fast can modern humans throw relative to apes |
modern humans=145 km/h apes=32km/h |
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what is the fastest movement the human body can produce? |
throwing at 145km/h |
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what are the 4 medial rotators of the humerus? |
-pectoralis major -deltoids -teres major -latisimus dorsi |
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What are two characteristics of the Homo neanderthalensis scapula relative to human scapula? |
-neanderthal scapular is much more robust -there is a dorsal sulcus on the axillary border for the insertion of teres minor |
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what is the significance of the Neaderthal's dorsal sulcus on the axillary border for the insertion of teres minor |
-stronger teres minor=stronger medial rotation |
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which is longer, human or H. Neaderthalensis clavicle? |
Neaderthal clavicle is longer providing greater strut for a large thorax |
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What is the difference between the neanderthal and human infraspinus fossa? what is the significance of this? |
neaderthal infraspinus fossa is larger allowing greater lateral humus rotation. this is needed to counter the effects of large adducter muscles. |
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what are three characteristics of neanderthal's humerus, what does this indicated about how it used its arms? |
-crests of pectoralis major and deltoid are very well developed -very robust shaft and greater cortical thickness than humans -this indicates that the neaderthal was a very good thrower |
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does Homo floresiensis have a cranial twist in its clavicle? |
no, it is similar to a human clavicle |
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in which direction is the glenoid fossa of the Homo floresiencis oriented? what form of locomotion does this suggest? |
H. floresiensis glenoid fossa is oriented laterally. This indicates that it was not aboreal |
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What is Homo floresiencis humeral torsion? what does this suggest about activities carried out by the arms? |
Homo floresiencis humeral torsion=115 degrees compared to human 140 degrees. this indicates that it would have held its arms differently and may have had trouble manipulating objects |
