第 40 至 43 題為題組 An ancient skull unearthed recently indicates that big cats originated in central Asia—not Africa as
widely thought, paleontologists reported on Wednesday.
Dated at between 4.1 and 5.95 million years old, the fossil is the oldest remains ever found of a
pantherine felid, as big cats are called. The previous felid record holder—tooth fragments found in
Tanzania—is estimated to be around 3.8 million years old.
The evolution of big cats has been hotly discussed, and the issue is complicated by a lack of fossil
evidence to settle the debate.
“This find suggests that big cats have a deeper evolutionary origin than previously suspected,” said
Jack Tseng, a paleontologist of the University of Southern California who led the probe.
Tseng and his team made the find in 2010 in a remote border region in Tibet. The fossil was found
stuck among more than 100 bones that were probably deposited by a river that exited a cliff. After three
years of careful comparisons with other fossils, using DNA data to build a family tree, the team is convinced
the creature was a pantherine felid.
The weight of evidence suggests that central or northern Asia is where big cats originated some 16
million years ago. They may have lived in a vast mountain refuge, formed by the uplifting Himalayas,
feeding on equally remarkable species such as the Tibetan blue sheep. They then dispersed into Southeast
Asia, evolving into the clouded leopard, tiger and snow leopard lineages, and later movements across
continents saw them evolve into jaguars and lions.
The newly discovered felid has been called Panthera Blytheae, after Blythe Haaga, daughter of a
couple who support a museum in Los Angeles, the university said in a news release.
【題組】40. According to the passage, why is the origin of big cats a hot issue?
(A) Because not many fossils have been found.
(B) Because they moved across continents.
(C) Because no equipment was available for accurate analysis.
(D) Because they have evolved into many different species of felid.