国产热热热精品,亚洲视频久久】日韩,三级婷婷在线久久,99人妻精品视频,精品九热人人肉肉在线,AV东京热一区二区,91po在线视频观看,久久激情宗合,青青草黄色手机视频

 
 
您現(xiàn)在的位置: Language Tips > BBC > Media English

Sawfish 'virgin births' astonish science 野生鋸鰩單性繁殖

媒體英語會帶大家一起學(xué)習(xí) BBC 撰稿人在報道世界大事時常用到的單詞和短語。

Sawfish 'virgin births' astonish science 野生鋸鰩單性繁殖

The sawfish, a cousin of the shark, is an endangered species

研究人員首次發(fā)現(xiàn)了一種生活在佛羅里達州河口的能夠單性繁殖后代。人們推測這是此類物種的一種生存機制。此發(fā)現(xiàn)被刊登在《當(dāng)代生物學(xué)》雜志上。以下是 Jonathan Webb 的報道:

Despite growing up to 12 feet in length with a vicious-looking snout, the smalltooth sawfish is critically endangered. Researchers from Stony Brook University in New York were doing a survey of the creatures to check on their genetic diversity.

They were surprised to find seven female fish that had no sign of a genetic father. They were all daughters of a virgin birth or parthenogenesis – this bizarre mechanism in which embryo grows from an unfertilised egg may be more common than scientists thought.

In captivity, sharks, reptiles and turkeys have all been known to surprise zookeepers and farmers with virgin births. But these fish are the first vertebrate virgin offspring ever found in the wild.

Glossary 詞匯表 (點擊單詞收聽發(fā)音)

巩义市| 淮阳县| 叙永县| 西华县| 阿巴嘎旗| 金塔县| 濮阳市| 视频| 驻马店市| 五峰| 喜德县| 五寨县| 保康县| 青海省| 萝北县| 奉节县| 石河子市| 吉安县| 保山市| 深州市| 洞口县| 民乐县| 德惠市| 南昌市| 始兴县| 石阡县| 手机| 牡丹江市| 柳州市| 色达县| 拜城县| 体育| 东港市| 泰兴市| 邹平县| 兴业县| 都匀市| 民乐县| 横山县| 哈巴河县| 石嘴山市|