UNIT B: EVOLUTION

UNIT B: EVOLUTIONMessana

Evolution Movie ClipSECTION #1B:Unicellular: Singlecell; 1 cell Ex: Bacteria

Multicellular:2 or more cells Ex: Algae

Mammals:

Mass ExtinctionWhen a large # of species DIE out suddenly2 Major Ones:1) Permian- 250 million yrs ago (end of Paleozoic Era) 90% of OCEAN LIFE died out .the LARGEST MASS EXTINCTION!!

2) Cretaceous - 65 million yrs ago (end of Mesozoic Era) Dinosaurs became extinct

Section #2:BIOLOGICAL EVOLUTION Process through which SPECIES CHANGE over time due to a CHANGE IN GENETIC MATERIAL that is passed through GENERATIONS.

Theory of Evolution

1st Life with DavidEARLY IDEAS:LAMARCK: (p 18B)FrenchAnimals ACQUIRED traits during their lifetime and passed them on to their OFFSPRING

EX:

DARWIN: (p 19B)BritishNATURAL SELECTION members of a species that are BEST SUITED to the ENVIRONMENT (nature) will survive & reproduce. SURVIVAL of the FITTEST!4 principles to support EX: Beaks of Finches(Galapagos Islands)

Charles darwin

Voyage of BeagleDates: February 12th, 1831Captain: Charles DarwinShip: H.M.S. BeagleDestination: Voyage around the world.Findings: evidence to propose a revolutionary hypothesis about how life changes over timeVogage route

DARWINS 4 PRINCIPLESOVERPRODUCTION:When plants or animals REPRODUCE, it makes MORE OFFSPRING than actually survive & reproduce EX: fish & turtle eggs

Overproduction VARIATIONThere are NATURALLY occurring differences in TRAITS due to different GENETIC MATERIALS or due to MUTATIONS-this is the PHENOTYPE of the organism (HOW it LOOKS on the outside)

Variations get passed onEX: BROWN vs BLUE eyes

MORE VARIATIONEX:NEMO had a short fin

NO 2 zebras have the same STRIPE pattern

DARWINS PRINCIPLES (CONT.)ADAPTATION:INHERITED TRAIT that gives an organism an Advantage in its environment over other members.EX: Move faster (cheetah); blend in (lions); camouflage (chameleon); shape of tail fin (fish)

SELECTION:Organisms with an ADAPTATION will SURVIVE & REPRODUCE and PASS ON the ADAPTATION SURVIVAL OF THE FITTEST!

ADAPTATIONInherited trait that gives an organism an ADVANTAGE in its particular environment over other members of the group; become more common from one GENERATION to the next!EX: - Fish with curved tail swim faster (speed)- White fur rabbits blend in to snow better in arctic climates (camouflage)- Birds with stronger beaks can get food better (feeding)Bears can hibernate when their food source is scarceBeetle with horns can fight off beetle without horns (defense)

Adaptation ActivityWill YOU survive????? I Will Survive!

Human who wants 2 flyProblem: NO wings!!!

Plane..with wings..Adaptation: non winged human jumps from winged vehicle AndFLIES WHOOP WHOOP!!

SPECIATION & ISOLATIONEvolution of a NEW SPECIES from an old species, due to ENVIRONMENTAL CHANGESPECIATION is due to ISOLATION!!!

A1A22 populations of SAME SPECIES separated; cant reproduce; differing mutations occur; each evolves 2 DIFFERENT SPECIESISOLATION causes SPECIATION

25Evidence for Evolution:1) Fossil Record2) Biological Evidence:A.)Homologous Structures = similar structure with different function, means common ancestry (Ex: forelimbs)B.)Analogous Structures = similar function, but not from common ancestorC)Vestigial Organ = organ or structure used in an ancestor, still present but not used in the evolved organism (Ex: leg bones in whales, appendix in humans)

Homologous Structures

Vestigial Organs

Evidence of Evolution: FossilsFossils show change in a single species over time or similarities between species

Evolution of the Modern HorseEvidence of Evolution: Comparative AnatomyAnalogous Structures different anatomical structure but similar function that arise from common environmental demands

Human Vestigial Organs3)GENETIC/DEVELOPMENTAL EVIDENCEA) Similarities in embryologyB)Matching gene/DNA sequencesEvidence of Evolution: Molecular BiologyMolecular Biology - the genetic structure of an organismThe key to understanding how traits are passed from one generation to the next is DNA analysisScientists can tell how closely related organisms are by studying their DNAThere does not have that much of a difference in a gene sequence to be a different organism!

Evidence of Evolution: EmbryologyEmbryology shows similar developmental stages amongst different species

Similarities in Embryos

Humans Speeding Up EvolutionEvolutionary TreesHow do we represent this relationship?

Evolutionary Tree also known as a phylogenetic tree; it is like a family tree, but it shows the evolutionary relationships between species branching back to common ancestors. CoevolutionCoevolution when 2 (or more) organisms or things affect each others evolution/evolve together dependent on each other

Genotype vs PhenotypeGenotype: Set of GENES responsible for traits within you (come from your ancestors lets hope your ancestors are.CUTE, FUNY, SMART, ATHLETIC, MUSICALLY INCLINEDSORRYfor some of you!! :0 ..LOL!!

Phenotype: the PHYSICAL EXPRESSION of those traits (what you can see!! how CUTE you ALL are!! PhenotypesHomologous/Vestigial StructuresExample of EvolutionSo how do animals and plants adapt to their environment over time?

Elephant Adaptation Video- showhttps://www.youtube.com/watch?v=CXcRw6Piaj8

htthttps://www.youtube.com/watch?v=CXcRw6Piaj8ps://www.youtube.com/watch?v=CXcRw6Piaj8w evolution of the Earth affects the evolution of a species

http://player.discoveryeducation.com/index.cfm?guidAssetId=0B5B292A-983E-4327-A27D-B647383BF293&blnFromSearch=1&productcode=US

Which Brings Us Back ToNatural SelectionOr Survival of the Fittest

What does Survival of the Fittest really mean?

In the next few scenarios,describethe phenotype that would most likely be selected to survive

Survival of the FittestScenario 1: DroughtThere has been a drought and all of the grass has dries up and dies first, but the leaves on bushes and trees are slower to diewho survives the longest?

Animals with short legs but long necksAnimals with long legs, but short necksAnimals with both long legs and long necksAnimals with both short legs and short necks

Survival of the FittestScenario 2: Predator is ApproachingA predator is approaching the herd, but is not hunting yetwho will know sooner and therefore have a better chance to escape?

Survival of the FittestScenario 3: Predator FightA predator has arrived. It is too late to run away or hide, the animals must fight off the predatorwho has the best chance at fighting?

Survival of the FittestScenario 4: BlizzardThe weather becomes very cold. There is a blizzard and the land is covered in snowwho survives?

Survival of the FittestScenario 5: Volcanic EruptionThere has been a volcanic eruption. Lava flows down the mountain onto the plains and kills anything in its pathwho will make it?