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Principles of evolution , our heritage and The Origins of Life What was life like a long time ago How did we come into being? Evolutionary History Darwin did not come up with his theories all by himself. Malthus and others set up a foundation that would allow Darwin to think as he did.

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principles of evolution our heritage and the origins of life

Principles of evolution , our heritageand The Origins of Life

What was life like a long time ago

How did we come into being?

evolutionary history
Evolutionary History
  • Darwin did not come up with his theories all by himself.
  • Malthus and others set up a foundation that would allow Darwin to think as he did.
  • Others came up with the same theory Independently
the species problem
The “species problem”
  • Why do populations of organisms change over time?
  • If an organism is present in a particular area, it must be perfect for that area, so why then do exotic species pose a threat?
evolution vocabulary words
Evolution vocabulary words
  • Evolution: Change in lines of descent over time.
  • Microevolution: series of changes that give rise to a new species (population).
  • Macroevolution: major large scale patterns of change in groups of living organisms.
  • Population: a group of individuals of the same species
slide6
Populations evolve not individuals.
  • Populations exhibit great variability. When this variability changes over time is when we get new species. (micro evolution)
  • Sources of variation within a population
    • mutations create new alleles
    • crossing over during meiosis leads to new combinations of alleles
    • independent assortment mixes alleles
microevolution processes
Microevolution Processes
  • Mutation
  • Natural selection
  • Genetic Drift
  • Gene flow
  • Reproductive isolation
mutation
Mutation
  • Any heritable change in DNA sequence.
  • Three types
    • lethal mutation
    • neutral mutation
    • beneficial
  • The vast majority of mutations are probably invisible or harmful.
natural selection
Natural selection
  • Is the major process to produce populations that have different characteristics.
  • First described by Darwin
    • if a trait is more adaptive it improves the chances of producing offspring (adaptation)
    • it gives more of its alleles to the following generation (greater fitness)
genetic drift
Genetic drift
  • Random fluctuation of allele frequencies over time
  • Works better in small populations
  • Influenced by who starts a population
    • Bottleneck effect
    • Founder effect
gene flow
Gene Flow
  • Genes flow with the individuals of a population
  • Physical flow tends to minimize genetic variation, like shuffling the deck.
reproductive isolation and speciation
Reproductive Isolation and speciation
  • Species: are populations of individuals that can interbreed.
  • When separated by 10,000 or more generations many species can no longer interbreed.
  • Types of isolation
    • geographic, behavioral, biochemical
rates of evolutionary change
Rates of evolutionary change
  • Gradualism: Evolution is a slow and methodical process
  • Punctuated equilibrium: Evolution occurs in rapid bursts followed by long periods without change
evidence for microevolution
Evidence for Microevolution
  • Biogeography
  • Fossil record
  • Comparative morphology
  • Comparative biochemistry
life evolved on the earth about 3 8 billion years ago
Life Evolved on the Earth about 3.8 Billion Years Ago
  • Small organic molecules joined to form larger molecules
  • Genetic material originated
  • Organic molecules aggregated into droplets
    • Figure 22.4 (p. 514)
human evolution

Human evolution

We are a class of organisms called Mammals

mammals are vertebrates
Nerve cord

Vertebrae (backbone)

Brain

Mammals are vertebrates
mammals
Hair

Long infancy (comparatively)

Flexibility in responses due to large brain

Produce milk (mammary glands)

Mammals
primates
Primates
  • Monkeys & Apes Physically and Biochemical similar
hominoids
Hominoids:
  • Chimps and Man
    • Common ancestor about 5 million years ago
evolutionary trends from primate to human
Evolutionary Trends from primate to human
  • Upright walking
  • Precision and Power grip
  • Daytime color vision w/ depth perception
  • More generalized teeth for omnivore diet
  • Increase in brain size allows for new and abstract behavior
origins of primates
Origins of primates
  • 60 mya- nighttime omnivores
  • 40mya Daytime larger brains
  • 35mya ancestor to monkeys and apes and humans
humans
Humans
  • Roughly 200,000 years old (from H. erectus)
  • 15,000 years in the Americas
  • 35,000 years in Asia decline of Neanderthal
  • 2 modes
    • Multiregional hypothesis (humans from independent evolution in europe, asia, africa and Australia
    • Out of Africa, one ancestor
we are evolving now
We are evolving now
  • Our evolution is cultural not morphological
topic ecosystems

Topic Ecosystems

Biosphere:

the portion of the earth that supports life: land, air water

ecology
Ecology:
  • The study of the interactions of organisms with each other and theenvironment.
more words
More words:
  • Habitat: The place an organism lives
  • Community: collections of populations in a habitat.
  • Niche: physical and biological conditions under which a species can live (an organisms role)
  • specialist: has very narrow growth conditions
  • generalist: will grow under a wide range of conditions
relationships in ecology

Biology Major

Undeclared liberal arts

Relationships in ecology

habitat

community

specialist

niche

generalist

ecosystem
Ecosystem
  • One or more communities interacting with one another and with the physical environment.
ecosystems will change over time in a process called
Ecosystems will change over time in a process called:
  • Primary succession: life moves onto an area that previously had no life. Like on a new volcanic island.
  • Secondary succession: When man, fire, floods disturb a community, a progression of different forms of life inhabit the area for a while

Succession

a human example of succession

Near city

appartments

taller buildings

smaller lots

decay

City

large buildings

no yards

gentrificaiton

A human example of succession

Suburbs & tract housing

Large lots of land

the ecosystem organization

The ecosystem organization

Energy from the sun passes through the ecosystem

the two major classes of life
The two major classes of life
  • Autotrophs: (producers)
    • capture sunlight energy and incorporate it into organic compounds (sugar, Fa, Na, Aa)
  • Heterotrophs:
    • feed on the tissue products of autotrophs
    • Humans and all omnivores and carnivores
the major types of consumers
The major types of consumers
  • Herbivores eat plants
  • Carnivores eat animals
  • Parasites reside in or on living hosts and extract energy
  • Omnivores eat a variety of organisms
  • Detritivores: feed on partially decomposed organic mater
  • Decomposers: reduce waste and dead bodies to their chemical components
recycling
Recycling
  • Ecosystems require energy and nutrients they lose energy and give off nutrients

Autotrophs

Decomposers

Heterotrophs

recycling of components again
Recycling of components again
  • Unlike physical matter energy cannot be recycled
    • energy that is not passed on to the next tropic level is lost in the form of heat.
  • Trophic levels: A hierarchy of energy transfers
    • each level feeds on the lower level.
trophic levels

carnivores

herbevores

top carnivor

autotrophs

humans

wolves

cows

plants

300

15

1

1,000,000

Energy lost as heat

Energy lost as heat

Energy lost as heat

Trophic Levels

Level (1)

Level (1)

Level (1)

Level (1)

pyramids of energy

Carniv.

Carniv.

Carniv.

herbivores

herbivores

herbivores

autotrophs

Pyramids of energy

When one group outgrows the supporting group the result is

Unstable

autotrophs

biogeochemical cycles
Biogeochemical cycles
  • The Hydrologic cycle: How water is moved.
  • The carbon cycle
    • Important in global warming and the greenhouse effect
  • The Nitrogen cycle
    • An air intermediate moves these atoms across the planet
  • The Phosphorus cycle
    • Intense competition of plants and bacteria
impacts of human populations
Impacts of Human Populations
  • Increasing #’s. The worlds population is still growing.
    • Birth control programs have not been successful
population dynamics
Population dynamics
  • Population density- individuals per unit area
  • distribution patterns-
    • clumped, random, uniform
age structure of a population
Age structure of a population
  • Preproductive:
    • before sexual maturity
  • Reproductive:
    • 15-44 age when producing young
  • Post reproductive:
    • after sexual activity
population growth
Population growth
  • (births + immunization) - (death + emigration)
  • Rate of increase - zero is a balance between births and deaths
biotic potential
Biotic Potential
  • Maximum growth rate of a population given low death rates
  • Depends on
    • # of offspring per individual
    • time until sexual maturity
    • length of sexual maturity
actual rates of population increase
Actual rates of population increase
  • Are influenced by environmental conditions
  • Usually biotic potential is not reached because of rate limiting conditions
  • Limits include
    • disease
    • space
    • pollution
    • predation
carrying capacity
Carrying capacity
  • The number of individuals that a given area can support
  • Mankind has been very effective in increasing the carrying capacity of the earth.
human population growth
Human Population growth
  • Preindustrial:
    • Birthrates & deathrates are high population is level over time
  • Transitional
    • birth rates are high death rates are low population increases
  • Postindustrial
    • birth rates drop & death rates are low population levels off
effects of air pollution
Effects of air pollution
  • Industrial Grey smog
  • Brown automotive smog
  • Acid deposition
  • Damage to ozone
water scarcity and pollution
Water scarcity and pollution
  • 1/3 of food is from irrigated fields
    • irrigation causes salt buildup
    • increase in human population causes an increase in waste, insecticides, chemicals and pollution
coping with solid waste
Coping with solid waste
  • Loosing places to store waste (recycle)
  • Desertification is caused by overusing marginal lands
sex hormones and sex hormone mimics

CH

2

Sex hormones and sex hormone mimics

OH

OH

OH

O

Testosterone

Estrogen (Estradiol)

Diethylstilbestrol

H

C

C

OH

HO

Cl

C

Cl

CH

Cl

C

Cl

2

CH

CH

DDT

Cl

3

3