高中英语选修B1U5RevealingnatureAjourneyofdiscovery课件.pptx

1、Revealing natureHave you ever seen these mysterious animals?Look at the page from a sciencemagazine and answer the questions.1.What do you know about these animals?What makes them special?Komodo dragon:It evolved in Australia and spread westward Duck-billed platypus:The oldest discovered fossil of i

2、t dates back to about 100,000 years ago Nautilus:It often considered“living fossils”They are all species that exit thousands of years on earth;They are old and rare(unusual).2.What other similar animals do you know about?Share your knowledge with the class.Starting outKomodo dragon:(科莫多巨晰）科莫多巨晰）Komo

3、do dragons were first encountered by Western researchers in 1910.The researchers said the ancestor of the Komodo dragon most likely evolved in Australia and spread westward,reaching the Indonesian island of Flores 900000 years ago.The Komodo dragonThe Komodo dragon is the largest lizard in the world

4、.It can grow to three metres in length and can weigh about 135 kilograms.Despite its size and weight,it can run for short distances at up to 20 kilometres per hour.Duck-billed platypus:The first scientists to examine a preserved platypus body judged it a fake in the late 18th century.The oldest disc

5、overed fossil of the modern platypus dates back to about 100000 years ago.The Duck-billed platypusThe duck-billed platypus is a small egg-laying mammal(up to 60 cm in length)found only in Eastern Australia including Tasmania.As its name suggests,it has a mouth that looks like a ducks bill,while its

6、thick fur and flat tail are similar to those of a beaver（海狸海狸）.NautilusFossil records indicate that the nautilus has survived relatively unchanged for around 500 million years.That is why it is often given the name“living fossil.”1.How can seeds travel?How can this benefit plants?Seeds usually are c

7、arried by the wind,water,and animals.Plants can have a better chance at life.Watch the video and answer the questions.2.Can you think of another example of seeds travelling?Share it with the class.Dandelion seeds have little parachutes to catch the wind and go further;Humans can spread seeds if seed

8、s get stuck to their clothing or shoes.Understanding ideasA journey of DiscoveryCharles Darwin and his Theory of Evolution Charles Darwin(1809-1882)was an English geologist and naturalist.In his famous book On the Origin of Species,Darwin proposed the theory that organisms(individual life forms)evol

9、ve extremely slowly.He stated that the organisms that were better suited to their environments would survive and pass on their favourable characteristics to the next generation,while the less suitable organisms would gradually die out.He called this process“natural selection.”Charles Darwin 1.What s

10、pecies do you recognize in the picture?Look at the evolutionary tree and answer the questions.Paramecium,earthworm,snail,crab,fish,tortoise,bird,horse,human,frog,alga,moss,fern,plant2 What factors can cause the process of evolution?The ever-changing environment of nature;environmental changes;popula

11、tion immigration;genetic mutation;cultural preferences.Read the passage and talk about your understanding of the title.Most commonly,people believe that a journey means a trip from one place to another,especially over a long distance and literarily a journey refers to the process by which something

12、gradually changes and develops.The title may indicate that Darwins research work leading to his discovery of evolution and the origin of species.A young man who had left medical school without completing his degree.Whats more,his father predicted in his letter that he would be“a disgrace to yourself

13、 and all your family.”Despite all this,his adventures on this ship would lead to one of the most important scientific discoveries of all time.Beagle The beginning of the journeyCharles Darwin was a geologist and naturalist,fascinated by rocks,plants and animals.Darwin studied:various living things i

14、n their natural environments and samples of the plants and animals he had collected.He noticed:that some species of animals were very similar to each other.On his journey on the BeagleAt that time,people believed that all species had appeared on Earth at the same time,and had not changed since.Howev

15、er,as he studied these,Darwin asked himself the questions:Generate ideasHow did different species come to exist?Maybe animals evolved as they adapted to their changing environments？On the Galapagos Islands:He noticed that there was a difference between the finches on each of the islands.Look for mor

16、e evidenceIt seemed the beaks had evolved according to what food was available on that particular island.The Galapagos Islands(加拉帕戈斯群岛加拉帕戈斯群岛)在厄瓜多在厄瓜多尔西方约尔西方约10001000公里的太平洋公里的太平洋上，由上，由1414个散布在赤道附近个散布在赤道附近的小岛组成的小岛组成。Galapagos在西班牙语中的在西班牙语中的意思就是乌龟。此群岛正意思就是乌龟。此群岛正如其名，岛上有重量超过一百如其名，岛上有重量超过一百公斤的象龟，使达尔文一行人公

17、斤的象龟，使达尔文一行人大为吃惊，另外，还有长达一大为吃惊，另外，还有长达一公尺以上的鬣蜥，这种蜥蜴有公尺以上的鬣蜥，这种蜥蜴有住在海岸附近的海生型及住在住在海岸附近的海生型及住在内陆的陆生型，且两者不属同内陆的陆生型，且两者不属同种。种。The Galapagos Islands elephant tortoises鬣鬣 晰晰 Conolophus subcristatusRare birds on the islands Darwin suspected that the finches had evolved from a common ancestor,which had arrive

18、d on the islands a long time before and it had slowly evolved into many new species.Develop ideasThe theory of Evolution:living things,including humans had evolved from lower forms of life.Propose a theoryToday,On the Origin of Species is regarded as one of the most important works ever written.It h

19、as changed ideas about life on Earth forever.And it all began with the journey on the Beagle.Darwin was a determined man.He had strong curiosity and interests in science and was good at thinking and making discoveries.1 Why were many people“shocked”by Darwins theory?2 What kind of person was Darwin

20、according to the passage?At that time,many people believed that all species had appeared on Earth at the same time and had not changed since,but Darwins theory proposed that living things,including humans,had evolved from lower forms of life,which,as a result,shocked many people.Think and Share Char

21、les Darwin was a geologist and naturalist,fascinated by rocks,plants and animals.He left England on the ship,the Beagle,in 1831.The journey gave him the chance 1_(study)various living things in their natural environments.He noticed that some species of animals were very similar 2_ each other.At that

22、 time,people believed that all species had appeared on Earth at the same time,and 3_(change)since.But Darwin began to think differently.When the ship reached the Galapagos Islands in 1835,it 4_(be)the birds that interested him the most.He suspected that the different 5_(finch)had evolved from a comm

23、on ancestor,6_ had arrived on the islands a long time before.直击高考直击高考 to study to had not changed wasfinches which It was a 7_(complete)new idea-a theory of evolution.Darwin explained this theory in his book,On the Origin of Species.Many people refused to believe that living things,8_(include)humans

24、,had evolved from lower forms of life.But Darwins scientific studies were so convincing 9_ more and more people started to believe his theory.Today,the book is regarded as one of the most important works ever 10_(write).completelyincluding that writtenNew journeys of discovery are always on the way.