Transcript Evolution Test Review

Evolution Test Review
1. Give a definition for evolution. Why
do living things need to evolve?
• Definition: species change over time
• As the environment changes, living things
need to survive, so they must change as time
goes on
2. How are fossils dated?
• Radiometric/ Radiocarbon Dating: measures the
amount of radioactive isotopes in a fossil to
determine its age
– Pro: can give you the exact age of a fossil
– Con: can’t be used on really old fossils because the
radioactivity goes away with time
• Relative Dating: compares the age of a fossil to
other fossils found in the same rock layer
– Pro: can be used to give you an estimated age of really
old fossils
– Con: rock layers can be shifted by earthquakes or
mudslides and this can give an inaccurate estimate
3. How can we get evidence for
evolution from the fossil record?
• The fossil record shows us how living things
have changed their forms over time
4. What are homologous structures?
Give an example. How do they
provide evidence for evolution?
• Similar structures with different functions
• Example: a human’s arm and a bat’s wing
• Evidence: they show that there was a common
ancestor
5. What are vestigial structures? Give
an example. How do they provide
evidence for evolution?
• Structures that no longer serve a purpose but
had a purpose in an ancestor
• Example: Tailbone in humans; wings on
flightless birds
• Evidence: show how things change over time
6. How does embryology (study of
embryos/development) provide
evidence for evolution?
• Similarities among embryos show a common
ancestor
• Also show how things have changed over time
(ex – human embryos have gill slits and tails as
embryos that go away during development)
7. What molecular evidence can be
used to support the theory of
evolution? Why does it support the
theory?
• Similar DNA sequences and proteins
• The more close the DNA sequences and
proteins are, it is thought that the more
closely related the two species will be
8. How does biogeography provide
evidence for evolution?
• It shows that island species have a lot of
similarities to animals on the closest mainland
• It shows how species have adapted for the
climate that they live in
9. Explain Charles Darwin’s discoveries
(finches and tortoises).
• Finches:
– Darwin noticed that where there were nuts for
food, the finches had short, hard beaks
– Where there was fruit and insects for food, the
finches had long, thin beaks
• Tortoises:
– Darwin noticed that where there was low
vegetation, the tortoises had short legs and necks
– where there was high vegetation, the tortoises
had long legs and necks
10. What are adaptations? Give an
example of an adaptation
• Adaptation: a beneficial change that allows an
organism/species to survive
• Example: thick fur on a rabbit that lives in the
arctic
11. What 3 things can we learn by
studying cladograms?
• Cladograms show:
– Shared traits
– The order the traits appeared in
– Probable relationships
12. How do you read a cladogram?
• Reads from the bottom up
– Oldest/most common trait at the bottom
– Newest/least common trait at the top
• Each organism on the cladogram has all the
traits below it
13. What are Linnaeus’ 7 different
taxonomic groups from largest to smallest?
What can classifying things tell you about
evolution?
• Kingdom, Phylum, Class, Order, Family, Genus,
Species
• Classification can tell you how closely related
two species are and how recently they shared
a common ancestor – the more of the above
groupings they have in common, the more
closely related they are
14. How do you read a
dichotomous key?
• Select an organism/specimen to identify
• Begin reading the key at line 1
• Follow directions on key until you are able to
identify your organism/specimen
15. Describe survival of the fittest.
• The best adapted to the environment will
survive and leave offspring behind to continue
the species
• Example: the fastest running prey will be able
to avoid predators and survive better than
slower prey
16. What is the purpose of sexual
selection?
• Gives males traits to attract the best females
to mate with
• This allows the species to better survive
17. Describe extinction (include
background and mass). Why do
species become extinct?
• Background: happens over longer time
periods at a slow rate
• Mass: happens suddenly and drastically
(wipes out lots of species on a global level)
• Species become extinct because they lack the
variations needed to survive
18. Describe genetic drift. Include the
bottleneck effect and founder effect.
• Genetic drift: changes in the alleles of a
population due to chance
• Bottleneck effect: occurs when a “bottleneck
event” (ex – natural disaster) drastically reduces
the population so that it no longer resembles the
original population
• Founder effect: occurs when part of a
populations colonizes a new area and most likely
evolves into a new species
19. What is gene flow?
• Movement of alleles between populations
– Example: migration
20. What does it mean to be
biologically fit?
• It means that the individuals are able to
survive and reproduce
21. What are variations? Give an
example.
• Differences in a population
• Example: different beak types in finches
22. What is a gene pool?
• All the genes available to a population
23. What are allele frequencies?
• How often certain alleles are seen in a
population
• They can tell you which genes better help a
population survive (a more common gene
would be thought to be more beneficial)
24. What is natural selection?
• Organisms will inherit beneficial adaptations
that will help them survive and leave behind
more offspring than other individuals
25. What happened in the Wooly
Worm lab? Why was it easier to
find certain colors over others?
• “worms” of different colors were collected
during different timed intervals
• Certain colors stood out so it was easier to see
them and collect them than it was the colors
that could camouflage themselves against the
colors of the room
26. Describe directional, stabilizing, and
disruptive selection. Give examples.
• Directional: favors phenotype at one extreme
– Example: bacteria that are resistant to antibiotics will survive and
shift the population to all (mostly) have that same trait
• Stabilizing: favors the intermediate phenotype
– Example: gall flies lay their eggs in plants and that creates a “gall”
in the plant – the medium sized galls are left alone while the small
galls are destroyed by wasps and the large galls are destroyed by
woodpeckers
• Disruptive: favors both extreme phenotypes
– Example: bright blue (dominant trait) male buntings (birds) will
attack and kill blue-brown (intermediate pheno.) males and leave
the brown (recessive) males alone
27. How do you correctly type and
handwrite a scientific name? Give an
example.
• Two words, first letter of the first word capitalized
– Typed: in italics
– Handwritten: underlined
• Example:
Homo sapiens
Homo sapiens (pretend this is handwriting) 