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69 非洲象与亚洲象之间的差别
SCIENCE REPORT - September 19, 2001: African ElephantsBy Nancy Steinbach
（Start at 1'02" ）This is Bill White with the VOA Special English Science Report.
Scientists say African elephants that live in the forest and those that live in (1)grasslands are different enough to be considered (2)separate kinds, or (3)species. Until now, scientists believed all African elephants were the same genetically. They have long recognized the clear differences between African and Asian elephants.
One (4)genetic researcher said the difference between the two groups of African elephants is as large as the difference between a lion and a tiger. Researchers from the United States and Kenya announced the discovery in the publication Science.
They examined genetic differences in almost two-hundred African elephants in grasslands and forests. They collected (5)tissue from more than twenty groups of elephants in the wild over a period of eight years. They did so by firing small (6)sharp objects into the elephants. The (7)darts removed small pieces of skin and then dropped to the ground.
The researchers examined the genetic material from the elephants skin. They found great differences between the African elephants living in the forest and those that live on the grasslands.
The grassland elephant has large ears and (8)curving (9)ivory (10)tusks. People can see these elephants in zoos and in visits to Africa. The forest elephant is smaller and has round ears. Its tusks are straighter and longer. The ivory is slightly pink in color. The forest elephant is not often seen in the wild. Only one African forest elephant is in a zoo. It is in Paris, France.
The researchers say genetic differences show that the two kinds of African elephants began to develop into separate species more than two-million years ago. The research also shows that all grassland elephants are genetically the same. This means they all developed from one recent (11)ancestor. The forest elephants, however, are genetically different from each other. This means that elephants in forest groups rarely mate and reproduce with members of other groups.
The researchers say that only about two-hundred-thousand African elephants live in the forests. These elephants face a greater threat to their (12)survival than other elephants. The threats are from land development and other human activity. Scientists say it is important that the African forest elephant be recognized as a separate species so it can be protected.
This VOA Special English Science Report was written by Nancy Steinbach.
(1) ssland[ 5^rB:slAnd ]n.牧草地, 草原
(2) separate[ 5sepEreit ]adj.分开的, 分离的, 个别的, 单独的v.分开, 隔离, 分散, 分别
(3) species[ 5spi:Fiz ]n.种类, (原)核素n.[律]式样
(4) genetic[ dVi5netik ]adj.遗传的, 起源的
(5) tissue[ 5tisju: ]n.薄的纱织品, 薄纸, 棉纸, [生]组织, 连篇
(6) sharp[ FB:p ]n.高调, 内行, 利刃, 骗子adj.锐利的, 锋利的, 明显的, 强烈的, 刺耳的, 急剧的, 精明的, 敏捷的adv.整, 锐利地, 急速地
(7) dart [ dB:t ]n.标枪, 镖, (昆虫的)刺, 飞快的动作v.飞奔, 投掷
(8) curving[ 5kE:viN ]adj.弯曲的
(9) ivory[ 5aivEri ]n.象牙
(10) tusk[ tQsk ]n.长牙, 獠牙, 尖牙vt.以牙刺戳, 以牙掘, 用牙碰伤
(11) ancestor[ 5AnsistE ]n.祖先, 祖宗
(12) survival[ sE5vaivEl ]n.生存, 幸存, 残存, 幸存者, 残存物
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