2020-2021学年度第43期总第749期
Counting T. rex
吉林毓文中学 姜晓琳
I. Lead-in
What do you know about this animal?
 
T. rex (short for Tyrannosaurus rex)
 Basic information
 
They lived on Earth millions of years ago. 
Is it possible now to count how many T. rex there were?

II. Read for main idea
Main idea:
A team of researchers determined that approximately 2.5 billion T. rex existed in the world millions of years ago.
Type of writing:
news report

III. Read for details  
True or False questions
1. Having seen the Jurassic Park movie franchise, scientists wanted to know how many T. rex existed millions of years ago.
F
The Jurassic Park movie franchise is just used to lead the topic.

2. Enough fossils provided information for scientists studying the number of T. rex that existed.
F
Only 32 fossils have been found that gave enough information to know they were adults.

3. The research method used by Marshall’s team is of great help to relevant research.
T

4. The small T. rex population density means the small number of T. rex.
F
The total number seems huge, but at any given time in a very long period, the population density was small.
5. If the total number of T. rex was far less than 2.5 billion, we might not have the chance to know about them.
T
IV. Read for structure of news report  
 

V. Deep thinking 

1. Why did scientists try to find out how many T. rex existed? Just out of curiosity?
2. What does Holly Woodward, a paleontologist, mean when she says, “Being able to figure out how much we’re missing can be just as important as knowing how much we have”? 
What’s your opinion about “how much we’re missing”?
VI. Read for more
And in paleontology, we don't just find fossils. We also care about evolution and diversification, how groups have become diverse, how groups go extinct ... So we've learned three things that we can illustrate and use for predicting the future, what may happen to life.
We've learned that we can calculate the rate of extinction by looking at historical extinctions and at that rate of extinction, even at the minimal figures, it's at least one hundred times what it ought to be. Secondly, we've learned something about risk, which species are most at risk of extinction, and I think that's fairly straightforward. But we need the evidence to be able to argue the case. And thirdly, we've learned that the whole history of the Earth records a rich record of climate change. We don't need to do experiments, we don't need to imagine what a world would be like without the polar ice caps. It has existed and we can study it. 
     So to conclude, my aim has not been simply to spread doom and gloom, but to indicate that we have the power to change. And in order to change, we have to accept reality along the lines that we're mentioning. And we have to ask the right questions about what we should do. And in order to decide what we should do, we need to use evidence. And some great evidence comes from the history of the Earth and the history of life. 
                                                                       
--excerpt from a paleontologist’s TED Talk
What should we do? 

VII. Language study
Can you find these words and expressions in the text?
 
 
Can you analyze the sentence below?
By looking at how long T. rex could live (for about 28 years), when they reached sexual maturity (around 15.5 years) and how much they weighed when fully grown (roughly 6.8 metric tons), the team calculated that each T. rex generation time was approximately 19 years. 
*the team作主语；
*calculated 作谓语；
*后面that从句作宾语；
*by looking at…, 作方式状语；由how long…，when…and how much…引导的句子共同作looking at的宾语从句。

Search the Science website for more about this topic.