CH 6.2
Species Change Over Time
CH 6 Objectives
Identify early ideas and observations
on evolution
Explain how Darwin developed his
theory of natural selection
Identify Darwin’s 4 principles of natural
selection
Describe how new species can form
from previous species
Essential Questions and Understandings
What is evolution and who contributed to the
modern theory of evolution?
Compare and Contrast Artificial and Natural
Selection
What are Darwin’s 4 principles and how do
they lead to evolution?
What is speciation?
How can isolation of a group of individuals
lead to a new species?
Evolution
Evolution is defined as
change over time
It is the result of changes
in the genetic material that
are passed from generation
to generation
Organisms use adaptations
to have a better chance of
surviving and reproducing
History
 Lamarck was on of the first
scientists to suggest the idea of
change over the lifetime of an
organism (Giraffes Necks)
 Darwin studied plant and animal
species on the Galapagos Islands
(178 islands)
 He noticed that species were
different from island to island
 Looked at adaptations to certain
environments
 Looked at finches and their feeding
behaviors
Artificial Selection
When people (breeders)
produce new varieties of
animals over time
Select a certain desired trait
Breed two animals displaying
that trait
The result is offspring
displaying the trait
Natural  Darwin proposed the same thing was
Selection happening naturally in the animal
and plant world
 He based his ideas on 4 principles:
 Overproduction: When a species produces
more offspring than can live in the
environment
 Variation: mutations that naturally occur
in the genetic material
 Adaptation: any inherited trait that gives
an organisms an advantage to survive
 Selection: if a trait helps an organism
survive to reproduce, the trait has been
“selected”
Speciation
 The evolution of new species from an existing
organism
 Can occur when the environment changes
dramatically such as a volcanic eruption
 New species can also occur when the environment
changes gradually
Formation of New Species due to Isolation
Example from a population
of Cichlids (fish)
1. Water level is low, one
species lives in a lake
2. Level rises filling
shoreline, population
spreads throughout the
lake
3. Level falls, isolating the
fish from each other
4. New species
development that are
more successful in their
environment
Isolation Can Lead to New Species
 Scientist believe that Isolation is essential to
speciation
 Isolation can occur due to geographic changes such
as mountains building up
 Cases caused by isolation have led to the great level
of biodiversity on Earth
CH 7
Classification of
Living Things
CH 7 Objectives
 Explain why scientists classify living things
 Describe evidence scientist use to classify organisms
 Explain how scientific names are determined and give examples
 Use the 7 levels of classification to identify an organism
 Describe organisms found in each of the current 6 kingdom system
of classification
 Describe the 3 domains
 Describe how dichotomous keys can be used to identify organisms
 Utilize a dichotomous key to identify common household objects
Essential Questions and Understanding
 Understand how scientist study biological
relationships to classify living organisms
 How has our classification system changed over
time?
 Describe how we give organisms scientific
names and give and example.
 Use a dichotomous key to classify organisms
correctly
 Identify characteristics of organisms found in
the 6 kingdoms
 1600’s: organisms were classified based on appearance and behavior
 PROBLEM: Can be deceiving, not universal (i.e. they could not ALL agree on
a system for naming organisms)
 1700’s: 2 Kingdoms (Plant and Animal)
 Linnaeus set a standard 2 name system for each animal (Genus species)
Linnaeus developed a system for naming species and organizing them
into groups 1866: 3 Kingdom Sytem (plant, animal, protista)
 20th Century: Started using DNA and genes to classify related species
 1925: 2 Kingdoms (Prokaryota & Eukaryota)
 1938: 4 Kingdoms (Monera, Protoctista, Plantae, Animalia)
 1969: 5 Kingdom System (Monera, Protista, Plantae, Fungi, Animalia)
 1977: Current 6 Kingdom System
 2000’s:???? 7 Kingdoms???? No Kingdoms??? Domains??
Classification
 Classification is the process of arranging organisms
into groups based on similarities
 Taxonomy: science of naming and classifying
organisms
 To classify organisms scientists use similarities and
differences among species
 A classification system (such as one found in a field
guide can help you identify unfamiliar organisms
 A taxon is a group of organisms that share certain
traits based on shared ancestors.
 Not All organisms that look alike are closely
related
Binomial Nomenclature
 Each organism has a 2 part name
 Scientific name
 Written in Latin and Greek
 Genus species
 Genus: a group of species with similar
characteristics
 Species: the specific name for the organism
(contains the least number of organisms)
 EX) Homo sapiens (human), Aubrieta gracilis
(flower), Chameleo gracilis (chameleon),
Mammillaria gracilis (cactus)
7 Levels of Classification to Name a Species
Each level is more specific than the last
Kings Play Chess On Fat Green Stools
1.Kingdom
2.Phylum
3.Class
4.Order
5.Family
6.Genus
7.Species
Dichotomous Keys
Asks a series of questions that
can be answered in only two
ways.
Each answer leads to another
question until you identify the
organism
KEY TO THE CRITTERS ON BEBONK
1.
Has 1 hair………………………………………………..2
Has 2 hairs………………………………………………4
2.
Has a belly button…………………………………BIP
Has no belly button………………………………3
3.
Has 2 legs………………………………………………GLIP
Has 4 legs……………………………………………FOOP
4.
Has arms…………………………………………….GLOP
Has no arms……………………………………….NOP
Kingdom Plantae
Multicellular
Live on water and land
Obtain energy from sunlight
Have a nucleus, cell wall, chloroplast
EX) grass, trees, moss
Kingdom Animalia
Multicellular
Live on water and land
Obtain energy by eating food
Have a nucleus, no cell wall,
no chloroplast
Have the ability to move
EX) human, elephant dog, fish
bugs
Kingdom Protista
Most are unicellular
Nucleus
Have the ability to move
Some eat like animals
Some get energy from sunlight
EX) Sea weed, Kelp, Euglena
Kingdom Fungi
Takes nutrients from
environment
Rooted in one place
Have cell walls
Act as decomposers
EX) Mushroom, yeast,
molds
Kingdom Archaea
No Nuclei
Live in extreme
environments-high
heat, high salt, high
sulfer
EX)
Methanococcoides
burtonii
Kingdom Bacteria
Unicellular
No Nuclei
Reproduce by
dividing in two
Can move
EX) E. Coli