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Evolution
Chapter 15
Evolution
• What causes things to become different over
time?
• Many changes can be traced to mutations that
have occurred.
• Sexual reproduction causes variability.
Mutations introduce new traits into the gene
pool.
Evolution
Evolution
• Comes from the root word to evolve. To evolve,
means to change.
• Things change over time. Ex. Human height
• Charles Darwin was the most famous person to
study evolution.
• Darwin published a book , Origin of Species.
Evolution
• E:\Evolution_and_the_Success_or_Failure_of_
Species.asf
Species
• A group of organisms that can mate and
produce fertile offspring.
Lamarck’s Theory of Evolution
• Selective use or disuse of organs. Organisms
acquired or lost certain traits during their
lifetime, if they needed a trait they grew it, if
they didn’t need a trait, they lost it.
• Traits gained or lost could be passed on to
offspring
• Over time this change led to formation of new
species.
Lamark cont.
• He also proposed that all organisms have a
tendency to achieve perfection as a species,
therefore they constantly change.
Charles Darwin
• Naturalist
• Studied plants and animals for differences
• Collected specimens from the areas that he
visited for further study
• Talked to the local people about how plant and
animal life had changed over time.
Charles Darwin
• Five year voyage on the H.M.S. Beagle a
refitted warship.
• Traveled to the Galapagos Islands
• Studied nature; plants and animals.
Evolution
• E:\Charles_Darwin.asf
Evolution
• E:\The_Galapagos_Islands.asf
Charles Darwin’s Origin of Species
• Individual organisms in nature differ from one
another. Some of this variation is inherited.
• Organisms in nature produce more offspring
than can survive, and many of those that
survive do not reproduce.
Charles Darwin’s Origin of Species
• Because more organisms are produced than
can survive, members of each species must
compete for limited resources.
• Because each organism is unique, each has
different advantages and disadvantages in the
struggle for existence.
Charles Darwin’s Origin of Species
• Individuals best suited to their environment
survive and reproduce most successfully. The
characteristics that make them best suited to
survive their environment are passed to the
offspring. Individuals whose characteristics are
not well suited to their environment die or leave
fewer offspring.
Charles Darwin’s Origin of Species
• Species change over time. Over long periods,
natural selection causes changes in the
characteristics of a species, such as in size
and form. New species arise, and other
species disappear.
Charles Darwin’s Origin of Species
• Species alive today have descended with
modification from species that lived in the past.
• All organisms on Earth are united into a single
tree of life by common descent.
Evolution
• E:\Agents_of_Evolution.asf
Evidence of Evolution
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Geographic distribution
Fossil Record
Homologous body structures
Similarities in early development
Evolution
• E:\Fossils_and_the_Study_of_Evolution.asf
Evolution
• E:\The_Types_of_Fossils_and_How_They_For
med.asf
Artificial Selection VS. Natural
Selection
• What causes certain characteristics to benefit
an organism over others?
• Natural selection
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Speed
Strength
Intelligence
Coloration
Natural Selection cont.
• Product production
• Amount of food produced each season
Evolution
• E:\Elephant_Evolution.asf
Artificial Selection
• Many times determined by Humans
• Selective breeding, most milk, more meat.
• More fruit, larger, stronger.
• Environmental change caused by humans
• Peppered moth
Interactions among Organisms
• E:\Introduction___Interactions_and_Relationshi
ps_Among_Organisms.asf
Predation
• E:\Predation.asf
Symbiosis
• E:\Symbiosis.asf
Endangered Species
• Species that is close to extinction because of
environmental factors.
• Predation
• Habitat change
• Loss of food source
Speciation
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Formation of new species
Reproductive isolation
Geographic isolation
Change in feeding habits or food availability.
Classification
• Putting large amounts of material into an order
that allows easier identification.
• Library- Dewey Decimal System
• Phone book- Alphabetical order
• Textbook- Chapters that put similar information
into easy to find order
Scientific Names
• Names assigned to organisms to help identify
them.
• Aristotle was the first person to attempt a
classification system
• He classified according to where an animal or
plant lived.
• Air, land or water
• PROBLEMS???
Linnaeus’ System of Classification
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Developed binominal nomenclature
Two word naming system
Genus
species
Notice the Genus is capitalized the species is
not
• Based on Latin descriptive language
Linnaeus’ System of Classification
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Genus is a verb
Species is a noun
Homo sapien
Man-like
Classification
• E:\Basics_of_Biology__The__How_Living_Thi
ngs_are_Classified.asf
Evolution
• E:\Endangered_Species.asf
Evolution
• E:\Protecting_Endangered_Species.asf
Evolution
• E:\Extinction__Gone_Forever.asf
Evolution
• E:\Increased_Rates_of_Extinction_in_the_Mod
ern_World.asf