physiognomy

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physiognomy

by umaa » Sat Jan 31, 2009 7:39 am
Paleontologists’ study of the
physiognomy of the saber-toothed cat
illustrates how scientists extrapolate
function from form. Holophoneus, a cat
5 that appeared in North America in the
early Oligocene epoch in the Tertiary
period of the Cenozoic era, about 38
million years ago, had large upper
canines (“saber-teeth”) and a downward
10 extension, or flange, formed by the front
of the lower mandible. When the mouth
was closed, the canines rested just
outside the flange, which acted as a
guard for these down-pointing teeth; the
15 lower jaw could be opened extremely
wide to free the canines for use. Unable
to bite like a modern cat, the saber-
toothed cat is thought to have used its
canines to stab its victims.
20 The evolutionary line of the saber tooth
culminated about 2.5 million years ago
with the appearance of Smilodon and
Megantereon. Smilodon, the larger, was
at least as big as the modern African
25 lion (Felis leo) and had upper canines
that were sometimes as long as eight
inches. Because of its heavily-muscled
neck and forequarters, the saber tooth
was probably a slow animal that fed on
30 large, slow-moving prey. If that was the
case, the extinction of the mammals that
constituted the saber tooth’s prey
probably led to its extinction about
10,000 years ago.




It can be inferred from the passage that the evolutionary adaptations of the saber tooth






took place around 38 million years ago



were dependent on the evolution of the saber tooth’s prey



led to its extinction approximately 10,000 years ago



were insufficient to compensate for the disappearance of primary food sources



resulted in the emergence of the modern African lion

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by Bidisha800 » Sat Jan 31, 2009 2:52 pm
(c)
Hope you will come back to post the OA.
Drill baby drill !

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by umaa » Sat Jan 31, 2009 6:05 pm
The OA is D

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by ontopofit » Sat Jan 31, 2009 11:03 pm
Its D.

In D it is correctly said that the evolutionary adaptions of saber-tooth were not able to compensate for the extinction of their food resource.

C is wrong because it wrongly says that the evolutionary adaptions of saber-tooth itself led to its extiction.which is not the case,in fact it unability was the cause.