Change Over Time
and the Evolution of Living Things
Fundamental Concepts and Skills
1. The Fossil Record
a) A fossil is any evidence of an organism that lived long ago.
b) The approximate ages of fossils can be determined by how deeply they are buried in
sediments or by Radiometric dating using decay of atoms to determine exact age.
c) A history of life on earth can be reconstructed by dating fossils and examining layers of
sediments on the earth’s crust—this is known as the fossil record.
d) Fossils help scientists to understand the order in which changes in living things occurred on
earth this is called the fossil record. It helps reconstruct evolutionary history.
e) When no living organisms of a particular species are living it is considered extinct.
i. There are a great variety of extinct species in the fossil record that provides
clues to the conditions on the earth as well as how changes occur over time.
2. Structural Evidence of Evolutionary History
a) Organisms that share a common bone structure
a. Each structure is modified for the different functions of the organism. (wings)
b) Homologous structures are structures shared by different species that indicate a common
ancestor (whale pelvis).
c) Vestigial structures are organs/bones in organisms that are no longer used as they were in
the past.
i. Tonsils, tail bone in humans, pelvis in the whale
3.
a)
b)
c)
d)
e)
f)
g)
h)
i)
Natural Selection—changes in populations over time (4 Parts of Natural Selection)
All populations produce more offspring than the environment can support.
This leads to a struggle to survive—only a fraction of those born make it to adulthood.
There is great genetic variation (genetic variety, differences) among individuals in a
population due to mutations.
After the favorable mutation is passed on to offspring by surviving parents, it eventually
becomes an adaptation.
I. An adaptation is anything (structure or behavior) that an organism has that allows it
to survive to reproduce in its environment.
Those individuals best fit (with the most useful adaptations) to the environment where they
live survive and successfully reproduce more offspring that those without useful
adaptations.
I. Successful reproduction is the key to natural selection—there’s no advantage for
future populations in having a useful adaptation if they are not passed to offspring.
The unequal ability of individuals to survive and reproduce leads to gradual change in
populations’ generation after generation.
Real life examples of natural selection in action include pesticide resistance in insects and
antibiotic resistance in bacteria. (Mrs. Phipps Leg!!)
Natural Selection can only work through variation already present in DNA
Over time, two population (separated for whatever reason) can evolve so differently they can
no longer interbreed. (This is known as speciation)
Citation
LS 13 b
p.153
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153-157
LS 13 a
p. 153157
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Text
170-183
LS 13 a,
c
p. 150151, 162
Online
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170183;
186-189
4. Passing of Traits, Genetics, and Evolution
a) Remember: Only traits present in parent DNA can be passed to offspring—evolution ONLY
act on traits which are inherited.
b) Mutations are the ultimate source of genetic variation.
I. Mutations may result in a favorable change which leads to adaptation.
II.
Mutations may result in no change in survival.
III.
Mutations may result in an unfavorable change which may negatively impact survival.
c) If a species does not include traits that enable it to survive in its environment or to survive
changes in the environment, then the species may become extinct.
5. The history of evolutionary biology
a) Lyell- One of the first scientists to recognize that organisms change over time. He had the
right idea—just not HOW it happens.
b) Malthus- discovered that population size could affect and be affected by the amount of
resources available.
c) Darwin- developed the evolutionary theory by natural selection. He published his book on
the topic called The Origin of Species by Means of Natural Selection in 1859, years after his
discovery was completed.
I. Darwin’s finches- the size and shape of the finch’s beak evolved because the type of
food available and the need for all finches to have food.
d) Wallace- also developed his own concept of evolution by natural selection similar to Darwin’s
at the same time as Darwin.
p.164167
LS 13 a
p.164165
LS14:a,b
,c
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book
162-169
Green
Text
Book15
9-163
LS5:a
Green
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Book
200-218
6. Classification- the arrangement of organisms into orderly groups based on structural
similarities and evolutionary history.
a) Binomial Nomenclature- the two name system for giving organisms a scientific name.
a. The scientific first name is the genus and is the first letter of the genus is always
capitalized.
b. The scientific last name is the species and the first letter is always lower case.
c. Both the names are underlined or italicized.
b) The 6 Kingdoms
Online
a. Archaebacteria- The most ancient living things on Earth—prokaryotic bacteria that live Text
in extreme environments/conditions
197-231
i. Hot Springs, Volcanoes, Arctic Ice, etc.
b. Eubacteria- prokaryotic bacteria that do not live in extreme conditions like E. coli.
c. Protists- eukaryotic unicellular, or simple multicellular organisms with a variety of
ways to survive. (amoebas, algae, seaweed)
d. Fungi- eukaryotic, mostly multicellular organisms (mushrooms, molds, and the disease
athlete’s foot)
e. Plants- eukaryotic multicellular organisms that use photosynthesis to produce food.
(maple trees, daises, grasses)
f. Animals- eukaryotic multicellular organisms (insects, sponges, crabs, and bats)
c) Dichotomous Key- a guide that is used to identify and classify unknown organisms
d) Carolus Linnaeus- a botanist known as the father of taxonomy. His system for naming,
ranking, and classifying organisms is still in wide use today.
Whale Evolutionary and Fossil Record:
Organization of Living Things and Evolutionary History: