Name ___________________________
Evolution Unit B 1.3
1. When did Darwin publish his book on evolution? __1859___________________________
2. Darwin’s work is still considered the Theory of Evolution? A scientific theory is a statement based on __observation____and
______experiment__. pg. 29___________
3. What happens if continued observation and experiment support a theory’s statement?
__It is widely accepted___________
4. A theory that has been widely accepted is used to __explain _____ and_predict_____ natural __phenonmena_____________.
5. Using the chart on pg 29, what three areas do scientists use as evidence for evolution?
__fossil_______evidence, _biological_____evidence, and __genetic_______ evidence.
6. Darwin gathered many specimens of fossils__that caused him to think that species appear to have a __common______
ancestor.
7. What is a common ancestor? _an early form of an organism from which several later forms have descended_______
8. Which main idea in the theory of evolution does the idea of a common ancestor support?
______natural selection_________________________________________________________
9. True or False:. Scientists comparing modern plants and modern algae to fossil algae would say they all
share a common ancestor.
10. What kind of evidence do scientists returning to the Galapagos Islands today find to support Darwin’s ideas?
_________fossil and biological evidence_________________________________________________
11. These scientists study the _structure_______ and the ___development_________ of living things.
12. What conclusions do these scientists come to through their observations?__
__Modern organisms are related to earlier specimens___________________________
13. Evidence for evolution can also be observed within the _physical__ structures of adult
organisms such as vestigial_____ organs and ___homologous____structures with different functions. pg___________
14. _Vestigial__ organsr are physical structures that were fully developed and __functional____ in an _earlier group__ of
organisms but are reduced and __unused_ in ____later___ species. pg.______
15. Give an example of a vestigial organ. ____pelvic bones in a whale- ancestor used to walk, human appendix-???_____
16. Researchers use vestigial organs to show that modern organisms having these organs are _related _____ to a
____common_____ ancestor.
( NOT IN BOOK)-Similar structures with different functions are called HOMOLOGOUS STRUCTURES.
17. Scientists have compared the anatomy of living things and noticed that many different species share ___similar
___structures_____.
Look at pg 31. Describe how some scientists compare similar structures.
a lizard’s __leg______, a bat’s _wing_______ and a manatee’s ___flipper__
18. Do they have a similar function? __No___________
19. However, even though these structures are used differently, some scientists believe this similarity in structure indicates that
these organisms shared a _common__ancestor________.
20. What process caused the variations in form and functions of these homologous structures?
__natural selection______________.
21. What factors influence natural selection? different __environments_______,; different__pressures_______________.
.
22. Scientists also observed similarities in the early development of different organisms as an _embryo_____ and the study is
embryology.
23. See page 32. What organisms are being compared? __chicken________, _rabbit_______, and a ___salamander___________.
24. As the organism continues to develop, what happens to the similarities?
_________They begin to change to distinct characteristics_______________
25. The key to understanding how traits are passed from one generation to the next lies in the study of__DNA_____, which is the
___genetic __ _material___ found in all cells.
26. What else does DNA contain? __the code that a cell uses to put together all the materials it needs to function properly.______
27.What is the code in DNA made of? __4 sub units called bases__
28.What letters represent the bases in DNA? ___Adenine, Guanine, Thymine and Cytosine._____
29. What is a gene? _a segment of DNA that relates to s specific trait or function in an organism____________________
and each gene has a particular _sequence____ of bases. pg.____________
30. What is a clock gene and its function? _a gene in mammals that relates to the function of walking and sleeping________
31. What do evolutionary scientists believe concerning the similarities in the sequences between two organisms?
_________The more matches in the sequences the more closely they are related.__________
32. Even though the two organisms appear so different, much of the __functioning ____ of their __cells__is similar.
On a separate sheet of paper draw a graphic organizer showing Evidences of Evolution. Use the words biological, genetic,
homologous structures, vestigial structures, embryology, and fossils,