Change over time worksheet.

 Answer these questions on a separate piece of paper to keep in your binder.

Explain the theory of change over time (evolution). Changes to a species that occur over time leading to the formation of a new species.

Explain the 4 following ways that scientists say they have evidence for change over time.

1.      Anatomical evidence- Homologous structures indicate a common link among many animals based on features of the body

2.      Fossil evidence- Shows the history of animals/ organisms from the past and up to today in the rocks

3.      Embryological evidence- a study of the development of an organism from the first stages of life.

4.      Chemical evidence- Similar DNA between different organisms, shows a historical link to a common ancestor

What is adaptation? Changes that occur to increase the chances of an organism’s survival

What is extinct? When a species dies out

What are Homologous Structures? Define and then give an example Homologous structures are body parts found on different organisms/ animals that have similar structures. Example: A bats wing has 5 digits/ fingers a wrist and 3 arm bones, so does a human. This information dealt with the pictures of the lion’s paw, bat wing, and whale flipper in the textbook.

What is Natural Selection? The survival and reproduction of those organisms best adapted to their environment.

What was the book that Darwin wrote? The Origin of the Species

What does the idea “survival of the fittest” mean? Those organisms best suited to their environment will live long enough to reproduce—same as Natural Selection

What are variations?  Variations are small differences that occur within a species. Variations are important to keep species ready for changes in the environment.

How can the environment select a specific animal or species? Give a brief explanation of what this is and then give an example. If the environment changes and now favors a different variation of a species or favors another species, organisms could be on the way to extinction.  An example of the environment favoring or selecting a specific organism would be the PEPPER MOTH of England. The white moths were safe on the white birch trees because the birds did not see them as well as black pepper moths. When the industrial revolution put all the black ash into the air it caused the white trees to turn black with soot. With the dark trees the black pepper moths were now more difficult to see than the white moths so they were able to live longer and produce more children. After England cleaned up the air the trees were cleaned of the soot by rainfall and once again had white bark. The birds were now able to see the black moths much easier and therefore the population of the black moth decreased and the white moths were once again hidden. Nature selected for the color of the moth that would live based on the color of the trees at the time.