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