CH 6.2 and CH 7Species Change Over Time and Classification of Living Things
EvolutionEvolution is defined as
change over timeIt is the result of changes in
the genetic material that are passed from generation to generation
(#23) Organisms use adaptations to have a better chance of surviving and reproducing
HistoryLamarck 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 islandLooked at adaptations to certain
environmentsLooked at finches and their feeding
behaviors
Artificial SelectionWhen people (breeders)
produce new varieties of animals over time
Select a certain desired traitBreed two animals displaying
that traitThe result is offspring
displaying the trait
Natural Selection
(#15) Darwin proposed the same thing was happening naturally in the animal and plant world
(#16) 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 (#27) 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 IsolationExample from a population of
Cichlids (fish)1. Water level is low, one
species lives in a lake2. 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 7Classification of Living Things
1600’s: organisms were classified based on appearance and behavior PROBLEM: Can be deceiving, (#7) 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 (#24)
1866: 3 Kingdom Sytem (plant, animal, protista) 20th Century: (21)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 (#5) 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 (#36) 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 NomenclatureEach organism has a 2 part nameScientific nameWritten in Latin and GreekGenus speciesGenus: a group of species with similar
characteristicsSpecies: 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 SpeciesEach level is more specific than the lastKings Play Chess On Fat Green Stools
1.Kingdom2.Phylum3.Class4.Order5.Family6.Genus
7.Species
Dichotomous KeysAsks 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 BEBONK1. 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 PlantaeMulticellularLive on water and landObtain energy from sunlightHave a nucleus, cell wall, chloroplastEX) grass, trees, moss
Kingdom AnimaliaMulticellularLive on water and landObtain energy by eating foodHave a nucleus, no cell wall, no
chloroplastHave the ability to moveEX) human, elephant dog, fish
bugs
Kingdom Protista
Most are unicellularNucleusHave the ability to moveSome eat like animalsSome get energy from sunlightEX) Sea weed, Kelp, Euglena
Kingdom Fungi
Takes nutrients from environment
Rooted in one placeHave cell wallsAct as decomposersEX) Mushroom, yeast, molds
Kingdom ArchaeaNo NucleiLive in extreme
environments-high heat, high salt, high sulfer
EX) Methanococcoides burtonii
Kingdom Bacteria
UnicellularNo NucleiReproduce by dividing in
twoCan moveEX) E. Coli