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Its Origin and Evolution. Organization of Life on earth. Levels of Organization. Biosphere Ecosystems Communities Populations Organisms Organs and Organ Systems Tissues Cells Organelles Molecules. Levels of Organization. Biosphere.

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levels of organization
Levels of Organization
  • Biosphere
  • Ecosystems
  • Communities
  • Populations
  • Organisms
  • Organs and Organ Systems
  • Tissues
  • Cells
  • Organelles
  • Molecules
biosphere
Biosphere
  • Everywhere within the Earth’s atmosphere where life exists.
ecosystems
Ecosystems
  • The biotic and abiotic factors within an environment
    • Interactions between organisms
    • Interactions between organisms and the environment
    • Cycling of Nutrients
    • Energy flow
community
Community
  • All living organisms in a particular region
population
Population
  • All individuals of a species in a particular area
organism
Organism
  • A single living thing
organs organ systems
Organs & Organ Systems
  • Organ
    • Specialized body parts made of tissues
    • Tissues work together to perform a specific function
  • Organ System
    • Groups of organs that work together to perform specific functions
tissue
Tissue
  • A group of similar cells
slide12
Cell
  • Basic unit of:
    • Life
    • Structure and function
  • Contains DNA
organelle
Organelle
  • Structural component of a cell
molecule
Molecule
  • Chemical structure consisting of atoms
diversity of life
Diversity of Life
  • Domain Bacteria
    • Prokaryotic
  • Domain Archaea
    • Prokaryotic
    • Live under extreme conditions
  • Domain Eukarya
    • Protists (unicellular eukaryotes)
    • Kingdom Plantae (photosynthetic)
    • Kingdom Fungi (decomposers)
    • Kingdom Animalia (ingest others)
evolution
Evolution
  • On the Origin of Species, Charles Darwin
    • Contemporary species arose from a succession of ancestors
      • “descent with modification”
    • Natural Selection
      • Mechanism for descent with modification
early earth the origin of life
Early Earth & the Origin of Life
  • Chemical and physical processes on early Earth may have produced very simple cells through a sequence of stages:

1. Abiotic synthesis of small organic molecules

2. Joining of these small molecules into polymers

3. Packaging of molecules into “protobionts”

4. Origin of self-replicating molecules

slide18

Earth formed about 4.6 billion years ago

  • Earth’s early atmosphere contained water vapor and chemicals released by volcanic eruptions
  • Experiments simulating an early Earth atmosphere produced organic molecules from inorganic precursors, but such an atmosphere on early Earth is unlikely
slide19

Miller & Urey

CH4

Water vapor

Electrode

NH3

H2

Condenser

Cold

water

Cooled water

containing

organic

molecules

H2O

Sample for

chemical analysis

other explanations
Other Explanations
  • synthesis near submerged volcanoes and deep-sea vents
other explanations1
Other Explanations
  • Extraterrestrial Sources
    • Carbon compounds have been found in some meteorites that landed on Earth
abiotic synthesis of polymers
Abiotic Synthesis of Polymers
  • Small organic molecules polymerize when they are concentrated on hot sand, clay, or rock
  • Protobionts
    • aggregates of abiotically produced molecules surrounded by a membrane or membrane-like structure
    • could have formed spontaneously from abiotically produced organic compounds
      • Example: small membrane-bounded droplets called liposomes can form when lipids or other organic molecules are added to water
slide23

The first genetic material was probably RNA, not DNA

  • RNA molecules called ribozymes have been found to catalyze many different reactions, including:
    • Self-splicing
    • Making complementary copies of short stretches of their own sequence or other short pieces of RNA
  • Early protobionts with self-replicating, catalytic RNA would have been more effective at using resources and would have increased in number through natural selection
fossils
Fossils
  • Formation
    • Sedimentary rocks
    • Low humidity
    • Ice
    • Amber
  • Dating
    • Strata & Index Fossils
      • Relative Dating
    • Radiometric Dating
      • Absolute Dating
    • Paleomagnetism
le 26 7

Accumulating

“daughter”

isotope

LE 26-7

1

Ratio of parent isotope

to daughter isotope

2

1

Remaining

“parent”

isotope

4

1

8

1

16

1

2

3

4

Time (half-lives)

slide28

Ceno-

zoic

Meso-

zoic

Humans

Paleozoic

Land plants

Animals

Origin of solar

system and

Earth

1

4

Proterozoic

Eon

Archaean

Eon

Billions of years ago

2

3

Multicellular

eukaryotes

Prokaryotes

Single-celled

eukaryotes

Atmospheric

oxygen

geologic time scale
Geologic Time Scale
  • Each era is a distinct age in the history of Earth and its life, with boundaries marked by mass extinctions seen in the fossil record
    • Occasions when global environmental changes were so rapid and disruptive that a majority of species were swept away
  • Lesser extinctions mark boundaries of many periods within each era
le 26 8

Millions of years ago

600

500

400

300

200

100

0

100

2,500

Number of

taxonomic

families

80

2,000

Permian mass

extinction

)

Extinction rate

60

1,500

Number of families (

Extinction rate (

40

1,000

Cretaceous

mass extinction

LE 26-8

)

20

500

0

0

Cambrian

Ordovician

Silurian

Devonian

Carboniferous

Permian

Triassic

Jurassic

Cretaceous

Paleogene

Neogene

Proterozoic eon

Ceno-

zoic

Paleozoic

Mesozoic

mass extinctions
Mass Extinctions
  • Permian
    • Killed about 96% of marine animal species and 8 out of 27 orders of insects
    • Cause = volcanic eruptions
  • Cretaceous
    • Killed many marine and terrestrial organisms, notably the dinosaurs
    • Cause = meteor impact
  • Mass extinctions = opportunities for adaptive radiations
early life
Early Life
  • Oldest known fossils are stromatolites
    • rocklike structures composed of many layers of bacteria and sediment
    • Date back 3.5 billion years
  • Prokaryotes were Earth’s sole inhabitants from 3.5 to about 2 billion years ago
electron transport systems
Electron Transport Systems
  • Produce ATP (adenosine triphosphate) from ADP (adenosine diphosphate)
photosynthesis
Photosynthesis
  • Oxygenic photosynthesis probably evolved about 3.5 billion years ago in cyanobacteria
  • Effects of oxygen accumulation in the atmosphere about 2.7 billion years ago:
    • Posed a challenge for life
    • Provided opportunity to gain energy from light
    • Allowed organisms to exploit new ecosystems
eukaryotic life
Eukaryotic Life
  • Oldest fossils of eukaryotic cells date back 2.1 billion years
  • theory of endosymbiosis
le 26 13

Cytoplasm

DNA

Plasma

membrane

Ancestral

prokaryote

Infolding of

plasma membrane

Endoplasmic reticulum

Nucleus

Nuclear envelope

Engulfing of aerobic

heterotrophic

prokaryote

Cell with nucleus

and endomembrane

system

LE 26-13

Mitochondrion

Mitochondrion

Engulfing of

photosynthetic

prokaryote in

some cells

Ancestral

heterotrophic

eukaryote

Plastid

Ancestral

photosynthetic eukaryote

evidence for endosymbiosis
Evidence for Endosymbiosis
  • Similarities in inner membrane structures and functions
  • Both have their own circular DNA
multicellular eukaryotes
Multicellular Eukaryotes
  • The common ancestor of multicellular eukaryotes dates back 1.5 billion years
  • Larger organisms do not appear in the fossil record until several hundred million years later
multicellular eukaryotes1
Multicellular Eukaryotes
  • Colonies
    • collections of autonomously replicating cells
    • Some cells became specialized for different functions
the cambrian explosion
The “Cambrian Explosion”
  • Most of the major phyla of animals
    • Cnidaria and Porifera date back to the late Proterozoic
  • Molecular evidence suggests that many animal phyla originated and began to diverge between 1 billion and 700 million years ago
le 26 17

500

Sponges

Cnidarians

Echinoderms

Chordates

Brachiopods

Annelids

Molluscs

Arthropods

Early

Paleozoic

era

(Cambrian

period)

Millions of years ago

LE 26-17

542

Late

Proterozoic

eon

the move to land
The Move to Land
  • Plants, fungi, and animals colonized land about 500 million years ago
  • Symbiotic relationships
continental drift

Eurasian Plate

North

American

Plate

Philippine

Plate

Caribbean

Plate

Juan de Fuca

Plate

Arabian

Plate

Indian

Plate

Cocos Plate

Continental Drift

South

American

Plate

Pacific

Plate

Nazca

Plate

African

Plate

Australian

Plate

Antarctic

Plate

Scotia Plate

le 26 19

Volcanoes and

volcanic islands

Trench

Oceanic ridge

LE 26-19

Subduction zone

Oceanic crust

Seafloor spreading

le 26 20

By about 10 million years

ago, Earth’s youngest

major mountain range,

the Himalayas, formed

as a result of India’s

collision with Eurasia

during the Cenozoic.

The continents continue

to drift today.

0

Cenozoic

Eurasia

North America

By the end of the

Mesozoic, Laurasia

and Gondwana

separated into the

present-day continents.

65.5

Africa

South

America

India

Madagascar

Australia

Antarctica

By the mid-Mesozoic

Pangaea split into

northern (Laurasia)

and southern

(Gondwana)

landmasses.

Laurasia

LE 26-20

135

Gondwana

Mesozoic

Millions of years ago

At the end of the

Paleozoic, all of

Earth’s landmasses

were joined in the

supercontinent

Pangaea.

251

Pangaea

Paleozoic

tree of life
Tree of Life
  • The five kingdom system has been replaced by three domains: Archaea, Bacteria, and Eukarya
  • Each domain has been split into kingdoms
    • Kingdom
    • Phylum
    • Class
    • Order
    • Family
    • Genus
    • Species
le 26 22a

Chapter 27

Chapter 28

Red algae

Charophyceans

Chlorophytes

Proteobacteria

Chlamydias

Spirochetes

Cyanobacteria

Korarchaeotes

Gram-positive bacteria

Cercozoans, radiolarians

Diplomonads, parabasalids

Euglenozoans

Euryarchaeotes, crenarchaeotes, nanoarchaeotes

Alveolates (dinoflagellates, apicomplexans, ciliates)

Stramenopiles (water molds, diatoms, golden algae, brown algae)

LE 26-22a

Domain Eukarya

Domain Archaea

Domain Bacteria

Universal ancestor

le 26 22b

Chapter 29

Chapter 30

Chapter 28

Chapter 31

Chapter 32

Chapters 33, 34

Chytrids

Sponges

Sac fungi

Club fungi

Zygote fungi

Angiosperms

Choanoflagellates

Cnidarians (jellies, coral)

Arbuscular mycorrhizal fungi

Seedless vascular plants (ferns)

Gymnosperms

Amoebozoans (amoebas, slime molds)

Bryophytes (mosses, liverworts, hornworts)

Bilaterally symmetrical animals (annelids,

arthropods, molluscs, echinoderms, vertebrates)

Plants

Animals

LE 26-22b

Fungi

theories of evolution
Theories of Evolution
  • Gradualism
    • Hutton & Lyell
  • Lamarck
    • Use and Disuse
  • Darwin
    • On the Origin of Species
    • Descent with Modification
      • Common Ancestors
    • Natural Selection
natural selection
Natural Selection
  • How do environmental changes affect a population?
le 22 6

LE 22-6

Cactus eater. The long, sharp beak of the cactus ground finch (Geospizascandens) helps it tear and eat cactus flowers and pulp.

Seed eater. The large ground finch (Geospiza magnirostris) has a large beak adapted for cracking seeds that fall from plants to the ground.

Insect eater. The green warbler finch (Certhidea olivacea) used its narrow, pointed beak to grasp insects.

slide52

LE 22-11

A flower mantid

in Malaysia

A stick mantid

in Africa

natural selection1
Natural Selection
  • Antibiotic Resistance
ernst mayer
Ernst Mayer
  • Observation #1:
    • For any species, population sizes would increase exponentially if all individuals that are born reproduced successfully
  • Observation #2:
    • Populations tend to be stable in size, except for seasonal fluctuations
  • Observation #3:
    • Resources are limited
  • Inference #1:
    • Production of more individuals than the environment can support leads to a struggle for existence among individuals of a population, with only a fraction of their offspring surviving
slide55

Observation #4:

    • Members of a population vary extensively in their characteristics; no two individuals are exactly alike
  • Observation #5:
    • Much of this variation is heritable
  • Inference #2:
    • Survival depends in part on inherited traits; individuals whose inherited traits give them a high probability of surviving and reproducing are likely to leave more offspring than other individuals
slide56

Inference #3:

    • This unequal ability of individuals to survive and reproduce will lead to a gradual change in a population, with favorable characteristics accumulating over generations
artificial selection

Artificial Selection

Artificial Selection

Lateral

buds

Terminal

bud

Brussels sprouts

Cabbage

Leaves

Flower

clusters

Kale

Cauliflower

Stem

Flowers

and

stems

Kohlrabi

Wild mustard

Broccoli

evidence for evolution

LE 22-14

Evidence for Evolution
  • Homology (homologous structures)

Whale

Bat

Cat

Human

evidence for evolution1
Evidence for Evolution

LE 22-15

  • Comparative Embryology
    • Shows homologies not visible in adult forms

Pharyngeal

pouches

Post-anal

tail

Chick embryo (LM)

Human embryo

evidence for evolution2
Evidence for Evolution
  • Vestigial Structures
    • Remnants of structures once used in ancestors
evidence for evolution3
Evidence for Evolution
  • Molecular Homologies (similar biochemistry)
    • Similarities in protein structure and genes
slide64

LE 22-16

Percent of Amino Acids That Are

Identical to the Amino Acids in a

Human Hemoglobin Polypeptide

Species

Human

100%

Rhesus monkey

95%

87%

Mouse

69%

Chicken

54%

Frog

14%

Lamprey

some evidence of evolution
Some Evidence of Evolution
  • Biogeography
    • similar mammals that have adapted to similar environments have evolved independently from different ancestors
slide66

LE 22-17

NORTH

AMERICA

Sugar

glider

AUSTRALIA

Flying

squirrel

phylogeny
Phylogeny
  • Phylogeny is the evolutionary history of a species or group of related species
  • Systematics
    • morphological, biochemical, and molecular comparisons to infer evolutionary relationships
  • Cladistics
homology vs analogy
Homology vs. Analogy
  • Similarity due to shared ancestry
  • Similarity due to coevolution
    • Adaptation to similar environments

HOMOLOGY

ANALOGY

binomial nomenclature

LE 25-8

Binomial Nomenclature

Panthera

pardus

Species

Panthera

Genus

Felidae

Family

Carnivora

Order

Mammalia

Class

Chordata

Phylum

Animalia

Kingdom

Eukarya

Domain

slide71

LE 25-9

Panthera

pardus

(leopard)

Mephitis

mephitis

(striped skunk)

Lutra lutra

(European

otter)

Canis

familiaris

(domestic dog)

Canis

lupus

(wolf)

Species

Genus

Panthera

Mephitis

Lutra

Canis

Family

Felidae

Mustelidae

Canidae

Carnivora

Order

le 25 11

TAXA

Lancelet

(outgroup)

Salamander

Lamprey

Leopard

Turtle

Tuna

Hair

Amniotic (shelled) egg

CHARACTERS

Four walking legs

Hinged jaws

Vertebral column

(backbone)

Character table

LE 25-11

Leopard

Turtle

Hair

Salamander

Amniotic egg

Tuna

Four walking legs

Lamprey

Hinged jaws

Lancelet (outgroup)

Vertebral column

Cladogram

slide73

Cladogram of Six Kingdoms

and Three Domains

Section 18-3

DOMAIN ARCHAEA

DOMAIN EUKARYA

Kingdoms

Eubacteria

Archaebacteria

Protista

Plantae

Fungi

Animalia

DOMAIN BACTERIA

Go to Section:

slide74

Gene Pools

    • All genes present in a particular population
  • Allele Frequencies
    • The relative frequencies of genes in a population
slide75

LE 23-3

MAP

AREA

CANADA

ALASKA

Beaufort Sea

Porcupine

herd range

NORTHWEST

TERRITORIES

Fairbanks

Fortymile

herd range

Whitehorse

ALASKA

YUKON

hardy weinberg
Hardy-Weinberg
  • describes a population that is not evolving
    • Allele frequency constant
    • Genotype constant
  • segregation and recombination of alleles are at work
  • Mendelian inheritance preserves genetic variation
slide77

LE 23-4

Generation

1

X

CRCR

CWCW

genotype

genotype

Plants mate

Generation

2

All CRCW

(all pink flowers)

50% CW

50% CR

gametes

gametes

come together at random

Generation

3

50% CRCW

25% CWCW

25% CRCR

50% CR

50% CW

gametes

gametes

come together at random

Generation

4

25% CWCW

25% CRCR

50% CRCW

Alleles segregate, and subsequent

generations also have three types

of flowers in the same proportions

slide78

If p and q represent the relative frequencies of the only two possible alleles in a population at a particular locus, then

    • p2 + 2pq + q2 = 1
      • p2 and q2 (homozygous genotypes)
      • 2pq (heterozygous genotype)
slide79

The five conditions for non-evolving populations:

    • Extremely large population size
    • No gene flow
    • No mutations
    • Random mating
    • No natural selection
genetic drift

LE 23-7

Genetic Drift

CWCW

CRCR

CRCR

CRCR

CRCR

CRCW

CRCW

CRCR

CRCR

Only 5 of

10 plants

leave

offspring

Only 2 of

10 plants

leave

offspring

CRCR

CRCR

CRCR

CWCW

CWCW

CRCR

CRCW

CRCW

CRCR

CRCR

CRCR

CWCW

CRCR

CRCW

CRCR

CRCR

CRCR

CRCW

CRCW

CRCR

CRCW

Generation 1

p (frequency of CR) = 0.7

q (frequency of CW) = 0.3

Generation 3

p = 1.0

q = 0.0

Generation 2

p = 0.5

q = 0.5

bottleneck effect
Bottleneck Effect

LE 23-8

Original

population

Bottlenecking

event

Surviving

population

heterozygote advantage
Heterozygote Advantage
  • Sometimes heterozygotes (at a particular locus) have greater fitness than homozygotes
    • Ex. Sickle Cell
  • Natural selection will tend to maintain two or more alleles at that locus
slide83

LE 23-13

Frequencies of the

sickle-cell allele

0–2.5%

2.5–5.0%

5.0–7.5%

Distribution of

malaria caused by

Plasmodium falciparum

(a protozoan)

7.5–10.0%

10.0–12.5%

>12.5%

types of selection
Types of Selection
  • Sexual Selection
    • Results in sexual dimorphism
    • Intrasexual selection - members of one gender fight against one another for mates of the opposite gender
      • Usually results from picky mates (usu. Females)
slide87

LE 23-16

Asexual reproduction

Sexual reproduction

Generation 1

Female

Female

Generation 2

Male

Generation 3

Generation 4

perfection
Perfection?
  • Evolution is limited by historical constraints
  • Adaptations are often compromises
  • Chance and natural selection interact
  • Selection can only edit existing variations
slide89

Speciation - the origin of new species

  • Evolutionary theory
    • explain how new species originate and how populations evolve
  • Microevolution - adaptations that evolve within a population(within one gene pool)
  • Macroevolution - evolutionary change above the species level
slide90

LE 24-3

Similarity between different species.

Diversity within a species.

slide91

Reproductive isolation - impede two species from producing viable, fertile hybrids

    • prezygotic
    • postzygotic
prezygotic barriers
Prezygotic Barriers
  • Impede mating or hinder fertilization if mating does occur:
    • Habitat (geographic) isolation
      • Two species occupy different habitats, even though not isolated by physical barriers
slide94

Temporal isolation

    • Species breed at different times of the day, different seasons, or different years
      • cannot mix their gametes
      • Ex. orchids
prezygotic barriers1
Prezygotic Barriers
  • Behavioral isolation
    • Behavioral isolation: Courtship rituals and other behaviors unique to a species are effective barriers
prezygotic barriers2
Prezygotic Barriers
  • Mechanical isolation
    • Mechanical isolation: Morphological differences can prevent successful mating
prezygotic barriers3
Prezygotic Barriers
  • Gametic isolation
    • Gametic isolation: Sperm of one species may not be able to fertilize eggs of another species
postzygotic barriers
Postzygotic Barriers
  • Postzygotic barriers prevent the hybrid zygote from developing into a viable, fertile adult:
    • Reduced hybrid viability
      • Genes impair development
    • Reduced hybrid fertility
      • sterility
    • Hybrid breakdown
      • Some first-generation hybrids fertile
      • offspring of the next generation are feeble or sterile
slide99

LE 24-4a

Prezygotic barriers impede mating or hinder fertilization if mating does occur

Habitat

isolation

Temporal

isolation

Behavioral

isolation

Mechanical

isolation

Gametic

isolation

Individuals

of

different

species

Mating

attempt

Fertilization

TEMPORAL ISOLATION

BEHAVIORAL ISOLATION

MECHANICAL ISOLATION

GAMETIC ISOLATION

HABITAT ISOLATION

Postzygotic barriers prevent a hybrid zygote from

developing into a viable, fertile adult

Reduced

hybrid

fertility

Reduced

hybrid

viability

Hybrid

breakdown

Viable,

fertile

offspring

Fertilization

REDUCED HYBRID

VIABILITY

REDUCED HYBRID

FERTILITY

HYBRID BREAKDOWN

slide101

LE 24-5

Allopatric speciation

Sympatric speciation

slide102

LE 24-13

Time

Punctuated equilibrium model

Gradualism model

patterns of evolution
Patterns of Evolution
  • Adaptive Radiation
    • The process by which a single species or small group of species have evolved into several different forms that live in different ways.
      • Ex. Dinosaurs were the result of adaptive radiation of reptiles.
slide104

Figure legend: Adaptive Radiation. Diverging from an ancestral form, a group of organisms is suddenly able to exploit a major new range of habitats. Within each smaller habitat, local selection pressures give rise to new gene pools adapted for those conditions. If these groups eventually become reproductively isolated, they may become new species.

patterns of evolution1
Patterns of Evolution
  • Convergent Evolution
    • The process by which unrelated organisms come to resemble one another.
      • Ex. Penguins and Dolphins
patterns of evolution2
Patterns of Evolution
  • Coevolution
    • The process by which two species evolve in response to changes in each other over time
      • Ex. Hummingbird and some plants with flowers