A team of scientists that studied chimpanzees trained to use treadmills has gathered new evidence suggesting that our earliest apelike ancestors started walking on two legs because it required less energy than getting around on all fours. The five chimps also wore face masks used to help the researchers measure oxygen consumption. While the chimps worked out, the scientists collected data that allowed them to calculate which method of locomotion used less energy and why. The team gathered the same information for four adult humans walking on a treadmill. We were prepared to find that all of the chimps used more energy walking on two legs-but that finding wouldnt have been as interesting, Sockol said. what we found was much more telling. For three chimps, bipedalism was more expensive, but for the other two chimps, this wasnt the case. One spent about the same energy walking on two legs as on all fours The other used less energy walking upright。 These two chimps had different gaits and anatomy than their quadrupedal peers. Fossil and molecular evidence suggests the earliest ancestors of the human family lived in forested areas in equatorial Africa in the late Miocene era some 8 to 10 million years ago, when changes in climate may have increased the distance between food patches~ That would have forced our earliest ancestors to travel longer distances on the ground and favored those who could cover more ground using less energy. 41. Michael Sockol and his team were interested in B. how chimpanzees could be trained to use treadmills. D. why our apelike ancestors came to walk on two legs. A. calculated. B. exercised. 43. What did the researchers find in the experiment? B. Human walking used more energy than bipedal walking in chimps. D. Three chimps used less energy walking on two legs. A. creatures with four feet. B. creatures with two feet. 45. What does fossil and molecular evidence tell us about our earliest ancestors? B. They were forced to travel between food patches. D. They were much taller than modern man
2017届高考英语大一轮复习综合训练:必修4 Module 6《Unexplained Mysteries of the Natural World》(外研版含解析)
2017届高考英语大一轮复习综合训练:必修4 Module 3《Body Language and Non-verbal Communication》(外研版含解析)
2017届高考英语大一轮复习综合训练:必修1 Module 3《My First Ride on a Train》(外研版含解析)
2017届高考英语一轮复习学案:M1 Unit1《School life》(第2课时)(牛津译林版)
2017届高考英语大一轮复习综合训练:必修5 Module 3《Adventure in Literature and the Cinema》(外研版含解析)
2017届高考英语一轮复习学案:M1 Unit2《Growing pains》(第2课时)(牛津译林版)
2017届高考英语一轮复习学案:M1 Unit3《Looking good》(第1课时)(牛津译林版)
2017届高考英语大一轮复习综合训练:必修5 Module 2《A Job Worth Doing》(外研版含解析)
2017届高考英语大一轮复习综合训练:选修6 Module 4《Music》(外研版含解析)
2017届高考英语一轮复习学案:M1 Unit1《School life》(第1课时)(牛津译林版)
2017届高考英语大一轮复习综合训练:必修5 Module 1《British and American English》(外研版含解析)
2017届高考英语大一轮复习综合训练:必修3 Module 1《Europe》(外研版含解析)
2017届高考英语大一轮复习综合训练:必修3 Module 6《Old and New》(外研版含解析)
2017届高考英语大一轮复习综合训练:必修3 Module 4《Sandstorms in Asia》(外研版含解析)
2017届高考英语大一轮复习综合训练:选修8 Module 3-4(外研版含解析)
2017届高考英语大一轮复习综合训练:必修4 Module 4《Great Scientists》(外研版含解析)
2017届高考英语大一轮复习综合训练:必修1 Module 4《Social Survey—My Neighbourhood》(外研版含解析)
2017届高考英语大一轮复习综合训练:必修3 Module 5《Great People and Great Inventions of Ancient China》(外研版含解析)
2017届高考英语大一轮复习综合训练:选修6 Module 6《War and Peace》(外研版含解析)
2017届高考英语一轮复习学案:M1 Unit2《Growing pains》(第1课时)(牛津译林版)
2017届高考英语大一轮复习综合训练:选修6 Module 3《Interpersonal Relationships—Friendship》(外研版含解析)
2017届高考英语大一轮复习综合训练:选修7 Module 1-2(外研版含解析)
2017届高考英语一轮复习学案:M1 Unit3《Looking good》(第2课时)(牛津译林版)
2017届高考英语大一轮复习综合训练:选修6 Module 5《Cloning》(外研版含解析)
2017届高考英语一轮复习学案:M1 Unit3《Looking good》(第3课时)(牛津译林版)
2017届高考英语大一轮复习综合训练:必修2 Module 6《Films and TV Programmes》(外研版含解析)
2017届高考英语大一轮复习综合训练:选修7 Module 5-6(外研版含解析)
2017届高考英语大一轮复习综合训练:必修2 Module 5《Newspapers and Magazines》(外研版含解析)
2017届高考英语大一轮复习综合训练:必修5 Module 4《Carnival》(外研版含解析)
2017届高考英语大一轮复习综合训练:必修4 Module 1《 Life in the Future》(外研版含解析)