Question Sheet: Invisible fossils of the first animals

SCIENCE

Before reading:

1. What is a fossil?
2. When did animals first form — and where?
3. What are molecules?
4. Where might scientists look for clues to early life if there are no stone

   fossils of those organisms?

During reading:

1. What are the cores that Gordon Love examined, and where were they collected?
2. What are molecular fossils and how do they differ from conventional fossils?
3. How long ago did animals exist, based on the new molecular fossil data – and

   how much older is that than previous, conventional animal fossils?

4. One of the detected molecular fossils — 24-IPC — is a marker of the former

   presence of what class of animals?

5. Scientists sometimes try to determine the age of fossils on the basis of

   molecular clocks. What biological material do these “clocks” rely on?

6. What was the argument for why sponges might have been the first animals?

After reading:

1. Why do scientists care about the kinds of animals that lived in the oceans

   millions of years ago?

2. Are molecular fossils harder or easier to interpret than conventional

   stone-based ones? Explain your answer.

3. If you can’t “see” molecular fossils, what good are they in telling you

   something about the organisms they represent?

SOCIAL STUDIES

1. Charles Darwin was born on February 12, 1809 — 200 years ago. What

   hypothesis did he propose to describe evolution?

2. How does the study of fossils, conventional or molecular, contribute to

   understanding the evolution of species?

3. Darwin and Abraham Lincoln were born on the same day. In your opinion, who

   made a more important, lasting contribution to the world? Give at least three

   reasons to support your view.

4. Describe a day in the life of two scientists: one who studies conventional

   stone fossils and one who investigates molecular fossils. At the end of the day,

   which type of scientist would you prefer to be and why?

LANGUAGE ARTS

• Scientists study fossils of all types to better understand the emergence of

  new species and chronicle information on the lives of those that have gone

  extinct. Research an organism that went extinct in the distant past. Write an

  essay of five paragraphs or more describing what scientists know about that

  plant or animal based on the fossil record.

• Write new lyrics to a song (it can be something as simple as the “Happy

  Birthday” or “Yankee Doodle”) that have to do with paleontology and the

  investigation of fossil animals. Let your imagination run wild!