Name __________________________________________ Period _________ Date ________________
Chapter 16 -- Theory of Evolution
Charles Darwin (1809-1882)
◦ English ___________________________
◦ Took a trip around the world on a ship called _______________________________
◦ Mostly fascinated with the ___________________________ Islands
◦ Best known for his theory of ______________________ by natural selection
Darwin’s Journey
◦ Began in ____________
◦ Sailed on a ship called the H.M.S. Beagle
◦ Five year voyage sailing around the coast of _____________________
___________________________ and ___________________________
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Observations Aboard the Beagle
◦ Darwin collected 68 species of ___________________________
◦ Wrote about the different characteristics of habitats and species that live
there
◦ Species vary ___________________________
◦ There are similar organisms around that world with similar
ecological ___________________________
◦ Ex: Rhea birds in S. America and ___________________________ in Africa
◦ Species vary ___________________________
◦ Related animals species often occupy different habitats within a
___________________________ area
◦ Ex: Tortoise ___________________________ ___________________________
among Galapagos Islands
◦ Species vary ___________________________ ___________________________
◦ Some fossils of ___________________________ animals were similar to
living species
◦ Ex: Armadillo ___________________________ compared to modern day
armadillos
Darwin’s Findings
◦ Galapagos Islands
◦ Groups of animals _________________ from island to island
◦ Ex: tortoises and finches on the islands resemble each other
but differ in the shape and function of their __________________
and _____________________
◦ Believed these unique animals all came from a ______________________
________________________ and they adapted to their environment
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Evolution
◦ Development of new types of organisms _________________ __________________
◦ Heritable _______________________ in the characteristics within a population
from one generation to the next
Ideas of Darwin’s Time
◦ Scientists thought all species were ___________________________ and
unchanging
◦ The Earth was believed to only be a few ___________________________ (not
billions) of years old
◦ During Darwin’s time, new research was being done to figure out the
___________________________ of the Earth
◦ James Hutton was a geologist in 1700’s
◦ Made connections between mountains, valleys, and layers of
_______________
◦ Believed the _________________ was older than thousands of years -a time so old for the human mind to image
◦ The Earth changes very _______________________ and some layers can
accumulate as the environment is changing
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◦ Charles Lyell was a English ___________________________ that believed the
Earth’s surface continues to change
◦ He explained that past processes that occurred are still occurring
now
◦ Ex: ___________________________ erupted in the past and still
today
◦ Published a great work called ___________________________
_______ ___________________________ in 1830 that built on the
work of Hutton
◦ Darwin read this book while on his journey around
the world
◦ Jean-Baptiste Lamarck
◦ French naturalist that ___________________________ the idea that
populations of organisms change over time
◦ Proposed two hypotheses: Called Theory of
___________________________ ___________________________
◦ Organisms could ______________________ during their lifetime
by using or not using selected parts of the body
◦ Individuals could pass these ___________________________ traits
on to their offspring
◦ Ex: Giraffes could ___________________________ their neck by stretching
over a period of time to get the height they needed to eat and
survive and then pass the longer neck trait to their
___________________________
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◦ Thomas Malthus was an English economist in the 1790s
◦ Reasoned that if the human population grew continuously, there
would not be enough ___________________________ for everyone
◦ His reasoning explained why plants and animals produced more a
high amount of ___________________________ since a portion will not
___________________________ due to environmental factors
◦ Ex: Maple tree produces ___________________________ of seeds
each summer
◦ Ex: Oysters produce ___________________________ of eggs each
year with the understanding that only a fraction will survive
Darwin’s Ideas
◦ Around the same time Darwin and Wallace formed ____________________ to
explain evolution
◦ Darwin was able to publish his book first called _______ ________
__________________ ________ _____________________ in 1858
◦ Book explained how evolution occurs by means of
___________________________ ___________________________
Artificial Selection
◦ Darwin studied ___________________________ breeders
◦ Farmers would select to breed only ___________________ with the largest
fruit, or the ______________ that produce the most milk
◦ Darwin called this process ___________________________
___________________________
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◦ Nature provides the ___________________________ , and humans select hose
they find to be useful and allow them to breed and pass on
___________________ to offspring
Evolution by Natural Selection
◦ Mechanism from descent with ___________________________
◦ 1. Struggle for Existence
◦ Organisms produce more offspring than can _________________________
◦ Ex: dogs give birth to a ___________________ of puppies, but only a
majority will survive
◦ 2. Variation and Adaptation
◦ Traits vary within a species and their
environment called ___________________________
◦ These adaptations help increase ______________________ to survive
◦ Ex: _______________________ with coral snake and scarlet snake
◦ 3. Survival of the Fittest
◦ Organisms best ___________________________ for an environment will
survive best and ___________________________
◦ The ability for an organism to ___________________________ and pass
on adaptations
◦ 4. Natural Selection
◦ Process by which organisms with ___________________________ most
suited to their local environment survive and leave more
___________________________
◦ Organisms ___________________________ their mate based on desired
traits
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Common Descent
◦ Idea that every species must have ___________________________ by
reproduction from pre-existing ____________________ that arrange over time
◦ Ex: finch _____________________ at Galapagos
◦ All species – living and extinct – are descended from ancient _____________
ancestors
Transitional Species
◦ Organisms with features that are ___________________________ hypothesized
ancestors
Age of the Earth & Fossils
◦ Noted that fossils of extinct animals _________________________ living species
◦ Relative Age
◦ Age _________________________ to other fossils in order of old to young
◦ Absolute Age
◦ Using radioactive dating to get ________________ __________________ age
◦ Age of the Earth
◦ Geologists are certain based on evidence via radioactive dating to
indicate the Earth is about _________ _______________________ years old
◦ Fossils
◦ ___________________________ of an organism that died long ago
◦ Many fossils form a series that can trace back to an
ancient extinct ___________________________
◦ Superposition
◦ Idea that ___________________________ form in layers where the layers
closest to the _____________ are the younger than below
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Anatomy and Embryology
◦ Anatomy: study of the ___________________
◦ Embryology: study of ___________________________
◦ Homologous structures
◦ Anatomical structures that originated from the ________________
common ___________________________
◦ Ex: bones in arms of humans, penguins, alligator and bat
◦ Related _________________________ but _______________________ may differ
◦ Analogous Structures
◦ When structures have similar ___________________________ , but did
not develop the same way
◦ Ex: wings of bat vs. bird
◦ Vestigial Structures
◦ Organs that no longer serve a ___________________________ in an
organism
◦ Ex: human tail bone, appendix
◦ Embryology
◦ Similar patterns of embryological ___________________________ provide
further evidence that organisms have descended from a
___________________________ ancestor
◦ Many animals look ___________________________ during development
and produce ___________________________ tissue
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Genetics and Molecular Biology
◦ At the molecular level, the ___________________________ ________________ and
homologous molecules provide ___________________________ of common
descent
Phylogeny
◦ ___________________________ among groups of organisms
◦ Can make a “______________” of animals evolved
◦ Trunk of the tree would represent species that are
___________________________ related
◦ Branches represent a ___________________________ population or
lineage
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Evolution in Action
◦ Biologists tested the hypothesis by comparing ___________________________
from the various species
◦ DNA evidence supported hypothesis __________ that each lizard
evolved ___________________________ on each island
◦ Convergent Evolution
◦ Process by which ___________________________ species
evolve ___________________________ traits
◦ Ex: twig-dwelling species came from different ancestors but
evolved similar adaptations to their environment
Divergence & Radiation
◦ Divergence evolution
◦ Process by which the descendants of a ___________________________
ancestor diversify into species that each fit
___________________________ parts of the environment
◦ Ex: All breeds of dog share a common ancestor with wolves
◦ Adaptive Radiation
◦ Pattern of diversity when a new population in a new
___________________________ undergoes divergent evolution
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Coevolution
◦ Evolution is on-going and many species may evolve
___________________________
Coevolution
◦ When __________________ or more species have evolved adaptations
to each other’s ___________________________
◦ Ex:
◦ Predator/Prey Interactions
◦ Introduction of new species
◦ Creating antibiotics
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