Diversity of Life

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Diversity of Life
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Mutations cause diversity by changing
_________________________ in cells
DNA and as a result, proteins
Sexual Reproduction causes diversity by changing
genetic combinations in cells.
GENE SHUFFLING
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Diversity

• Estimated 5-30 million different kinds of species
  on the earth
• All species share similarities such as the
  genetic code, cellular structures, and
  adaptations to ways of life
• Where did these different types of organisms come
  from?

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Evolution

• Theory a well supported testable explanation of
  phenomena that have occurred in the natural world
  
• Evolution The process that has transformed life
  from its earliest beginning to the unending
  diversity that exists today
• Change over time

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Charles Darwin

• Joined H.M.S. Beagle in 1831
• Sailed around the world - 5 year voyage
• Observations from journey and collected evidence
  (plant and animal specimen) lead to theory of
  evolution
• Observations
• most species were well suited to environment they
  inhabited
• several ways in which organisms reproduced and
  survived

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Charles Darwin

• Fossil Collections
• Some fossils resembled organisms that were still
  alive
• Other fossils did not resemble anything he had
  ever seen

Heliobatis radians(Common name stingray or
skate)Eocene
Paratriakis curtirostris Fossil SharkCretaceous
Eurypterus remipes Upper Silurian
Published ideas in Origin of Species
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Galapagos Islands

• Group of small islands 1000 km west of South
  America
• Islands have very different climates
• Smallest, lowest islands were hot, dry, and
  nearly barren (little vegetation)
• Higher islands had greater rainfall and a
  different assortment of plants and animals

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Galapagos Islands
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Galapagos Islands

• Characteristics of many animals and plants varied
  noticeably among the different islands
• Did these separate species have a common ancestor?

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Galapagos Islands

• Tortoises differed from island to island
• Shape of the tortoises shell could be used to
  tell which island it was from

More Rainfall
Less Rainfall
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Galapagos Tortoises
Galapagos Tortoise photo by theBIGzoo.com
Photo courtesy Marc Shandro.
Photograph by Charlotte (AKA, "moxythecat")
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Galapagos Islands

• Darwin also studied several types of small brown
  birds
• Had different shaped beaks
• Assumed they were all different kinds of birds
• Later noticed that the birds he collected from
  the different islands were all finches

/www.galapagosonline.com/nathistory/wildlife/birds
/galapagosbirds.htm
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Santa Cruz.  Medium ground finch (female),
Geospiza fortis.
Large ground finch (female?), Geospiza
magnirostris.
Small ground finch (female), Geospiza fuliginosa.
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Struggle for Existence
Organisms compete for resources - not enough
materials/space for all organisms born
Survival of the Fittest
Organisms have differences adaptations -
adaptations are inherited characteristics -
physical, behavioral Ex. - adaptation have to
be suitable for the environment - adaptations
help organisms survive, increase fitness.
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Survival of the Fittest
Organisms that are better fit are more likely to
survive Organisms that survive get to
reproduce Organisms that reproduce pass their
genes and thus their adaptations to the next
generation
Guppy Natural Selection Simulation
Assignment
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Common Descent
Offspring of the same parents exhibit genetic
variability Variability allows them to inhabit
different niches i.e. compromise
NICHE physical and biological conditions
that an organism lives with AND the way it uses
those conditions
Downy Woodpeckers Males forage on small trees or
on small branches of large trees Females
forage on the trunks and larger limbs of large
trees.
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Example of Niche in Warbler Species
Left to right Cape May, Yellow-rumped,
Black-throated Green, Blackburnian, and
Bay-breasted Warblers. Black areas in stylized
conifers show where feeding is concentrated.
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Common Descent
Eventually descendents of common ancestors may be
very different from each other Descent With
Modification
Ex. Gazelle species feeding at different times
Dama Gazelle active during daytime
Arabian Sand Gazelle active at twilight
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Common Descent
Over time organisms gain different adaptations
and become different species EVOLUTION
New species shared common ancestors A single
Tree of Life can be made for all organisms
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Formation of New Species
Species a population that cannot interbreed
with another population and produce fertile
offspring Gene pools must be separated somehow
for species to develop
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Isolating Mechanisms- create separate gene pools
Behavioral Isolation - habitats overlap -
courtship behaviors differ Ex. Bird mating
calls, courtship dances
Geographical Isolation - habitats are
separated by geographical feature Ex. lakes
separate fish species, Colorado River separates
squirrel species
Temporal Isolation - habitats overlap -
reproduce at different times Ex. orchids
pollinate on different days,
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Diversity

• Taxonomy discipline of classifying organisms
  and assigning each organism a universally
  accepted name
• Grouping organisms by similarities has given
  taxonomists the present day system of
  classification
• Organisms placed into a particular group are more
  similar to each other than they are to organisms
  in another group

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Kingdoms and Domains

• The three-domain system
• Bacteria Archaea Eukarya
• The six-kingdom system
• Eubacteria Archaebacteria Protista
• Plantae Fungi Animalia
• The traditional five-kingdom system
• Monera Protista Plantae
• Fungi Animalia

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Three-Domain System

• Domain is a more inclusive category than any
  other larger than a kingdom
• Eukarya
• Bacteria
• Archaea

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Eukarya

• Composed of protists, fungi, plants and animals

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Bacteria

• Correspond to the Kingdom Eubacteria
• Unicellular
• Prokaryote

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Archaea

• Correspond to Kingdom Archaebacteria
• Unicellular
• Prokaryote
• Live in some of the most extreme environments
• Volcanic hot springs, brine pools, black organic
  mud devoid of oxygen

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Linnaeuss System of Classification(Largest to
Smallest)

• Kingdom (You already know these 5!!)
• Phylum
• Class
• Order
• Family
• Genus
• Species
• K P C O F G S
  

Scientific Name
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Binomial Nomenclature

• Each species is assigned a two-part scientific
  name
• Always written in italics
• First word is the genus
• Group of closely related species
• Always capitalized
• Second word unique to each species within the
  genus
• Always lowercase

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Classifying Organisms Using Dichotomous Keys

• Dichotomous keys can be used to identify
  unfamiliar organisms
• A series of paired statements that describe
  physical characteristics of different organisms
• Paired statements are always opposite statements
  and lead to more detailed statements which
  eventually determine the identity of the organism