We are the products of evolution, and not just evolution that occurred billions of years ago. As scientists look deeper into our genes (基因), they are finding examples of human evolution in just the past few thousand years. People in Ethiopian highlands have adapted to living at high altitudes. Cattle-raising people in East Africa and northern Europe have gained a mutation (突变) that helps them digest milk as adults.

On Thursday in an article published in Cell, a team of researchers reported a new kind of adaptation—not to air or to food, but to the ocean. A group of sea-dwelling people in Southeast Asia have evolved into better divers. The Bajau, as these people are known, number in the hundreds of thousands in Indonesia, Malaysia and the Philippines. They have traditionally lived on houseboats; in recent times, they’ve also built houses on stilts (支柱) in coastal waters. “They are simply a stranger to the land,” said Redney C. Jubilado, a University of Hawaii researcher who studies the Bajau.

Dr. Jubilado first met the Bajau while growing up on Samal Island in the Philippines. They made a living as divers, spearfishing or harvesting shellfish. “We were so amazed that they could stay underwater much longer than us local islanders,” Dr. Jubilado said. “I could see them actually walking under the sea.”

In 2015, Melissa Ilardo, then a graduate student in genetics at the University of Copenhagen, heard about the Bajau. She wondered if centuries of diving could have led to the evolution of physical characteristics that made the task easier for them. “It seemed like the perfect chance for natural selection to act on a population,” said Dr. Ilardo. She also said there were likely a number of other genes that help the Bajau dive.

1.What does the author want to tell us by the examples in Paragraph 1?

A Environmental adaptation of cattle raisers.

B New knowledge of human evolution.

C Recent findings of human origin.

D Significance of food selection.

解析：选B。B 推理判断题。 根据第一段的第一句和第二句可知，人类的进化不只发生在数十亿年前，在过去的几千年里也一直在进化。下面举的例子就是在说明这一点，即对人类进化的新的认识。故选B。

2.Where do the Bajau build their houses?

A In valleys.

B Near rivers.

C On the beach.

D Off the coast.

解析：选D。D 细节理解题。 根据第二段第四句 ...built houses on stilts in coastal waters... 可知，巴瑶人沿海居住。 故选D。

3.Why was the young Jubilado astonished at the Bajau?

A They could walk on stilts all day.

B They had a superb way of fishing.

C They could stay long underwater.

D They lived on both land and water.

解析：选C。C 细节理解题。 根据第三段第三句 We were so amazed that they could stay underwater much longer than us local islanders 可知令 Jubilado 感到惊讶的是巴瑶人可以在水下停留很久。astonished 与文中的 amazed 为同义异构。故选C。

4.What can be a suitable title for the text?

A Bodies Remodeled for a Life at Sea

B Highlanders’ Survival Skills

C Basic Methods of Genetic Research

D The World’s Best Divers

解析：选A。A 主旨大意题。 纵观全文，作者主要介绍了人类的进化不只发生在数十亿年前，近几千年人类也一直在进化。作者主要以巴瑶人为例，讲述了在从事潜水活动的过程中，他们的身体结构逐渐变得更加适应水下环境，由此可知 Bodies Remodeled for a Life at Sea 为适合的标题。故选A。