Unit 3 Study Guide
KEY – the answers are just highlights. For more details, examples, more in depth work, see student
notes, worksheets, lab activities, etc.
SUGGESTED Study Strategies (not required, but should be helpful)
 Flash Cards (scientists, facts, bird beaks, vocabulary, etc.)
 Create your own study guide or test (quiz yourself)
 Group Studying (maybe text a friend some questions)
 Memorization, Mnemonic Devices, Acronyms
 Reread, rewrite your notes, organize notes, and/or highlight key concepts
 Revisit daily opening activities, quizzes, worksheets, labs, etc.
 Visit teacher webpage to review any notes or handouts
VOCABULARY: Define and provide examples if able
Adaptation – The right tool for the job. A trait with a current functional role in the life history of an
organism that is maintained and evolved by means of natural selection. Examples: bird wings,
camouflage, hibernation, herding, poison, teeth, milking, etc.
Contrivance – A tool, but not quite right for the job. Objects used, or modified, to do something clearly
very different from what they were normally used for, and typically not highly efficient. Also known as
pre-adaptations. Example: Spinal column, larynx, land animals having flippers.
Vestigial – A useless tool. Organs that serve no useful function in an organism. For example: appendix,
tailbone, miniature legs/arm, wisdom teeth, blind fish having “eyes”, etc.
Homologous Structures – A similar structure between two different species that share a common
ancestor. For example: All mammals have similar arm structures, a human and a whale have the same
basic bones in their arms/fins.
Analogous Structures – A similar structure between two different species that do not share a common
ancestor. For example: bird wing and a bee’s wing.
Evolution – an organism slowly changing over time to better adapt to its environment.
Embryo – The early stage of an organism’s development. Occurs shortly after fertilization of the female
egg.
Natural Selection – Nature or the environment influencing which traits of an organism will become more
or less common in order for that organism to better survive in the environment.
Artificial Selection – Unnatural or human influences that choose which traits an organism will have. For
example: dog breeding where humans choose which dogs to breed together.
Fossil - A mineralized cast or impression of organisms or their body parts.
IMPORTANT PEOPLE: Summarize their contributions to evolution and natural selection.
Alfred Russel Wallace - 1858 (~25 years after Darwin) Researching evolutionary changes in Malaysia,
finding similar observations as Darwin.
James Hutton 1795 Theory of Geological change. Forces change earth’s surface shape. Changes are
slow. Earth much older than thousands of years
Thomas Malthus If population grew (more babies born than died) then Insufficient living space. Food
runs out. Darwin applied this theory to animals
Jean-Baptiste Lamarck Changes tend toward Perfection (Giraffe necks) Use and Disuse (Contrivance &
Vestigial). Inheritance of Acquired Traits
Charles Lyell 1858 Book: Principles of Geography. Geographical features can be built up or torn down.
Darwin thought if earth changed over time, what about life?
Charles Darwin – 1830’s voyage of the Beagle, around the world scientific exploration. Famous for
Galapagos Islands studying finches and land tortoises. Theory of Natural Selection- Depends on
resources in nature. Life inherits desirable traits. Takes a long time
Items to Review: Summarize the items and explain their importance.
Explain the difference between adaptation, contrivances, and vestigial structures.
Provide specific examples of adaptations, contrivances, and vestigial structures and explain why they fall
into each category.
See vocab section, but I expect good explanations on the test.
Compare and contrast homologous and analogous structures.
See vocab section, but I expect good explanations on the test.
Provide specific examples of homologous and analogous structures and explain why they fall into each
category.
See vocab section, but I expect good explanations on the test.
Review the key concepts to the Peppered Moth lab and the effects of populations on the moths in an
unpolluted (white) environment and a polluted (dark) environment.
As pollution changed the environment, different moths began becoming more common. Originally
before pollution, the white moths were better camouflaged and able to easier survive, but after
pollution the darker moths became better camouflaged and reproduced more. Nature/the environment
determined which moth would become more common.
Review the embryo puzzle and explain the difficulties with completing the puzzle. How do scientists say
that the puzzle connect to natural selection and evolution?
Difficulties: Almost all of the embryos looked exactly the same during their early stages. Scientists use
this as evidence that all of these organisms most likely came from a common ancestor and therefore all
begin their development very similar to each other.
Review Darwin’s Finches (notes and measuring activity). Explain why the finches on different islands
have different shaped beaks. How does natural selection cause these changes in beak sizes?
Finches on different islands have different beaks because their food sources were different. The food
source depicted the shape of the beak that was best suited to survive and the birds with the correct
beak shape/size bred more. So each island ended up with different types of finches.
Review the types of foods eaten by the different finches (beak sizes). Be sure to explain why a certain
beak size is easiest to eat a certain type of food.
Pictures are in the student notebooks. Larger beaks are used for larger foods like nuts and fruits.
Smaller sharper beaks are used for smaller foods. Sharp beaks are used to dig and stab insects and
worms.
Be able to explain how natural selection can change a structure of an organism over time.
The environment/habitat determines the traits that will allow an organism to survive easier. For
example, the polar bears have white fur to blend into their environment. The snow/icy environment
allowed/dictated that the white polar bears would be easier to survive. However, if the snow/ice were
to melt and the ground/dirt/grass becomes more common, the polar bear will have a harder time
surviving and the white fur trait might become lost or extinct.
Given graphical data, be able to find trends, make predictions, and summarize data.
Students will need to be able to look at a graph and analyze the graphs and explain what is happening.
We’ve made multiple graphs this unit (i.e. finch beak sizes, human skull graph analysis, etc), so they can
use those as examples.