EVOLUTIONEVOLUTION

EVOLUTIONEVOLUTION

The process of change through time.The process of change through time.

Evidences of EvolutionEvidences of EvolutionFossils-the remains of a once living Fossils-the remains of a once living

organismorganismTypes of fossilization:Types of fossilization:

Petrification Petrification ImprintImprintTar/Ice/AmberTar/Ice/Amber

FOSSILSFOSSILS

Fossils always form in sedimentary Fossils always form in sedimentary rock with the older organisms in the rock with the older organisms in the deeper layers.deeper layers.

FOSSIL LAYERSFOSSIL LAYERS

PETRIFIED FOSSILPETRIFIED FOSSIL

PETRIFIED WOODPETRIFIED WOOD

TARTAR

AMBER AMBER

IMPRINTIMPRINT

COMPARATIVE STUDIESCOMPARATIVE STUDIES

Evidence for evolution is also found Evidence for evolution is also found by by comparingcomparing::EmbryologyEmbryologyBiochemistryBiochemistryCytologyCytologyAnatomyAnatomy

COMPARATIVE EMBRYOLOGYCOMPARATIVE EMBRYOLOGY

COMPARATIVE EMBRYOLOGYCOMPARATIVE EMBRYOLOGY

Animals go through similar stages of Animals go through similar stages of embryological development.embryological development.This may show that they are related and This may show that they are related and

may share may share common ancestrycommon ancestry

COMPARATIVE COMPARATIVE BIOCHEMISTRYBIOCHEMISTRY

Organisms have similar chemicals, Organisms have similar chemicals, which may show common ancestry.which may show common ancestry.Ex. Ex.

Hormones are similar in many species.Hormones are similar in many species.Everything contains DNA.Everything contains DNA.Similar protein structure and construction.Similar protein structure and construction.Use ATPUse ATP……..

COMPARATIVE CYTOLOGYCOMPARATIVE CYTOLOGY

The study of cells is The study of cells is CYTOLOGYCYTOLOGY..All living things are made of cells, All living things are made of cells,

therefore, they may share a common therefore, they may share a common ancestor.ancestor.

COMPARATIVE ANATOMYCOMPARATIVE ANATOMY

Comparing the structures of different Comparing the structures of different animals to find similarities.animals to find similarities.Homologous StructuresHomologous StructuresAnalogous StructuresAnalogous StructuresVestigial StructuresVestigial Structures

HOMOLOGOUS STRUCTURESHOMOLOGOUS STRUCTURES

Structures having a similar origin, Structures having a similar origin, but are adapted for different but are adapted for different purposes.purposes.Ex. Human arm and whale flipperEx. Human arm and whale flipper

Same structure-Different functionSame structure-Different function

HOMOLOGOUS STRUCTURESHOMOLOGOUS STRUCTURES

ANALOGOUS STRUCTURES ANALOGOUS STRUCTURES

Structures are different but have the Structures are different but have the same basic function.same basic function.Ex. Bee wing and Bird wingEx. Bee wing and Bird wing

Different structure-Same functionDifferent structure-Same function

VESTIGIAL STRUCTURESVESTIGIAL STRUCTURES

Structures that presently have no Structures that presently have no known function, but may once have known function, but may once have been needed.been needed.Ex. Tonsils, appendix, whale, snake Ex. Tonsils, appendix, whale, snake

THEORIES OF EVOLUTIONTHEORIES OF EVOLUTION

Jean-Baptiste Lamarck (early 1800Jean-Baptiste Lamarck (early 1800’’s)s)Theory of use and disuseTheory of use and disuseHe said that characteristics which are He said that characteristics which are

acquired are inherited.acquired are inherited.Ex. Giraffes & Human MusclesEx. Giraffes & Human Muscles

THEORIES OF EVOLUTIONTHEORIES OF EVOLUTION

August Weismann (late 1800August Weismann (late 1800’’s)s)Disproved LamarckDisproved Lamarck’’s theorys theoryHe said that acquired characteristics are He said that acquired characteristics are

NOT inherited.NOT inherited.Studied miceStudied mice

THEORIES OF EVOLUTIONTHEORIES OF EVOLUTION

Hugo de Vries (late 1800Hugo de Vries (late 1800’’s)s)One of the first geneticistsOne of the first geneticistsDeveloped mutation theoryDeveloped mutation theory

Said mutations are a result of genes Said mutations are a result of genes segregating, then recombiningsegregating, then recombining

THEORIES OF EVOLUTIONTHEORIES OF EVOLUTION

Charles DarwinCharles Darwin““Father of EvolutionFather of Evolution””Observed variation in species on the Observed variation in species on the

Galapagos IslandsGalapagos IslandsFamous for his study of finches, among Famous for his study of finches, among

others.others.

DARWINDARWIN’’S THEORIESS THEORIES

Natural SelectionNatural Selection Organisms with Organisms with favorable adaptationsfavorable adaptations tend to tend to

survive and reproduce.survive and reproduce.

The 4 principles of Natural Selection:The 4 principles of Natural Selection:1. 1. OverproductionOverproduction-populations overproduce-populations overproduce2. 2. CompetitionCompetition-struggle for existence-struggle for existence3. 3. VariationVariation-leads to new generations that are better -leads to new generations that are better

adapted to environmentadapted to environment4. 4. Survival of the FittestSurvival of the Fittest - the ones best adapted, - the ones best adapted,

survive.survive.

VARIATIONVARIATION

A bell curve shows variation within a A bell curve shows variation within a population.population.

VARIATION OF HEIGHTVARIATION OF HEIGHT

GEOGRAPHIC ISOLATIONGEOGRAPHIC ISOLATION

Species that are separated from one Species that are separated from one another by natural barriers another by natural barriers (mountains, ocean, desert) can cause (mountains, ocean, desert) can cause new species to develop.new species to develop.Ex. Emu, Ostrich, RheaEx. Emu, Ostrich, Rhea

GEOGRAPHIC ISOLATIONGEOGRAPHIC ISOLATION

SPECIATIONSPECIATION

SpeciationSpeciationOver time, new species will develop due Over time, new species will develop due

to their isolation.to their isolation.Ex. Emu and Ostrich cannot interbreedEx. Emu and Ostrich cannot interbreed

ADAPTATIONSADAPTATIONS

An adaptation is a characteristic of An adaptation is a characteristic of an organism that helps it to function an organism that helps it to function in itin it’’s environment.s environment.

ADAPTIVE RADIATIONADAPTIVE RADIATION

The process by which a single The process by which a single species evolves into several different species evolves into several different forms that live in different ways. forms that live in different ways.

Causes diversity amongst the group Causes diversity amongst the group of organisms.of organisms.

ADAPTIVE RADIATIONADAPTIVE RADIATION

GRADUALISMGRADUALISM

Slow steady change over time Slow steady change over time (gradually)(gradually)

PUNCTUATED EQUILIBRIUMPUNCTUATED EQUILIBRIUM

Stable population makes a sudden Stable population makes a sudden and rapid change into something and rapid change into something new.new.

Punctuated equilibrium vs. Punctuated equilibrium vs. gradualismgradualism

ORIGIN OF LIFEORIGIN OF LIFE

In the beginning…In the beginning…______________, which happened about ______________, which happened about

_____________ years ago._____________ years ago.Then…Then…

Molten earth cooled, forming a Molten earth cooled, forming a ___________.___________.

Then…Then…Volcanoes erupted, spewing gases, Volcanoes erupted, spewing gases,

forming the ____________.forming the ____________.

ORIGIN OF LIFEORIGIN OF LIFE

The first gases in the The first gases in the primitive primitive environment were:environment were:NHNH

44- Methane- Methane

COCO22-Carbon Dioxide-Carbon Dioxide

NHNH33-Ammonia-Ammonia

HH22S-Hydrogen SulfideS-Hydrogen Sulfide

These gases combined to form These gases combined to form primordial primordial soupsoup

ORIGIN OF LIFEORIGIN OF LIFE

Early Earth was being bombarded by Early Earth was being bombarded by lightning and comets.lightning and comets.

Lightning caused molecules in the Lightning caused molecules in the primordial soup to reassemble into primordial soup to reassemble into CHON.CHON.Therefore, an organic molecule is born! Therefore, an organic molecule is born!

ORIGIN OF LIFEORIGIN OF LIFE

Simple organic molecules began to Simple organic molecules began to combine to form more complex combine to form more complex molecules.molecules.Ex. Simple proteins, carbohydrates, Ex. Simple proteins, carbohydrates,

lipids and nucleic acids.lipids and nucleic acids.This occurred around 3 billion years ago.This occurred around 3 billion years ago.

ORIGIN OF LIFEORIGIN OF LIFE

Simple archaebacteria are formed Simple archaebacteria are formed about 2.5 billion years ago.about 2.5 billion years ago.Archaebacteria evolved and adapted Archaebacteria evolved and adapted to the environment, forming simple to the environment, forming simple monera, which then evolved monera, which then evolved into____________, which then evolved into____________, which then evolved into____________.into____________.

Miller and Urey ExperimentMiller and Urey Experiment

In the 1950In the 1950’’s, the scientists s, the scientists conducted an experiment to re conducted an experiment to re create the formation of life. create the formation of life.

ExperimentExperiment