Transcript Patterns of Evolution

Patterns of Evolution
Coevolution
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Two or more species that interact may evolve
together.
Examples:
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Predator-prey
Parasites and hosts
Plants and their pollinators
Convergent Evolution
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Organisms that appear to be very similar, are not
closely related at all.
The environment selects for the phenotype
Examples:
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Sharks and Dolphins
Analogous structures are associated with
convergent evolution
Divergent Evolution
 When
closely related species become
more dissimilar usually because of
different habitats
 Adaptive radiation: related species
evolve from a single ancestral species
Things that effect evolution
 change
in climate/habitat: a trait that
was an advantage may no longer be an
advantage
 genetic drift:
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change in allele frequency by chance
events
greater impact on small populations
 migration:
species can be seperated or
exposed to new environments
 geographic
isolation: a species can be
seperated geographically (canyon,
different islands, etc.)
 mutations: new variations can arise by
random chance
 reproductive isolation: something
prevents organisms from sucessfully
breeding examples: different mating
seasons, different mating calls
Classification
 Taxonomy:
the branch of biology that
names and groups organism according to
their characteristics and evolutionary
history.
 Aristotle
was the first to use this method
but was replaced due to confusion
Carolus Linnaeus (1707-1778)
 Swedish
Naturalist
 Devised a system of grouping organisms
into categories based upon form and
structure
 Created seven different levels of
organization
7 Levels of Classification
 Kingdom
 Kindly
 Phylum
 Pass
 Class
 Connie
 Order
 Over
 Family
 Fresh
 Genus
 Green
 Species
 Salad
Binomial Nomenclature
Two
Name
Naming
System
Binomial Nomenclature
 System
that gives organisms two-part
scientific name
 Genus species
 Genus is capitalized and both are in italics
 Examples:
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Homo sapiens
Lynx rufus
3 Domain System
 Recently,
scientists have added a group
above Kingdom. Three groups, called
DOMAINS.
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Domain Eukarya - includes organisms
composed of eukaryotic cells (plants,
animals, fungi, protists)
Domain Bacteria - includes all prokaryotic
cells, Kingdom Eubacteria
Domain Archaea - includes only "ancient"
bacteria, Archaebacteria
Tree of life
 Phylogenetic
Tree: showing evolutionary
relationships among various species based
upon similarities and differences in their
physical and/or genetic characteristics.
Phylogenetic Trees
 Use
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a combination of:
Shared anatomical structures
Pattern of embryological development
Types of proteins
DNA sequencing
Closely Related
Node
Derived Character: Characteristics that
appear more recently in a group but are
not seen in older organisms
1. ______ Wings
2. ______ 6 Legs
3. ______ Segmented Body
4. ______ Double set of wings
5. ______ Jumping Legs
6. ______ Crushing mouthparts
7. ______ Legs
8. ______ Curly Antennae
Dichotomous Keys
A
step-by-step guide to help identify an
organism
 Follows a series of choices that lead you
to the organism’s name
Dichotomous Keys
1. Has green colored body ......go to 2
Has purple colored body ..... go to 4
2. Has 4 legs .....go to 3
Has 8 legs .......... Deerus octagis
3. Has a tail ........ Deerus pestis
Does not have a tail ..... Deerus magnus
4. Has a pointy hump ...... Deerus humpis
Does not have a pointy hump.....go to 5
5. Has ears .........Deerus purplinis
Does not have ears ......Deerus deafus
answers
A. Deerus magnus
B. Deerus pestis
C. Deerus octagis
D. Deerus purplinis
E. Deerus deafus
F. Deerus humpis