Transcript Evolution

Evolution
Unifying the Biological
Sciences after Darwin
What is Evolution?
- define it….
Evolution Definitions
• 1. any process of formation or growth; development:
the evolution of a language; the evolution of the
airplane.
• 2. a product of such development; something
evolved The exploration of space is the evolution of
decades of research.
• 3. any similar movement, especially in close order
drill.
• 4. a process of gradual, peaceful, progressive
change or development, as in social or economic
structure or institutions.
• 5. a motion incomplete in itself, but combining with
coordinated motions to produce a single action, as in
a machine
Evolution Definitions
• 6. a pattern formed by or as if by a series of
movements: the evolutions of a figure skater.
• 7. an evolving or giving off of gas, heat, etc.
• 8. Mathematics . the extraction of a root from a
quantity.
• 9. a movement or one of a series of movements
of troops, ships, etc., as for disposition in order
of battle or in line on parade.
• 10. Biology . change in the gene pool of a
population from generation to generation by
such processes as mutation, natural selection,
and genetic drift.
Evolution: Fact
• Has been observed in a large number of short lived
species
• Super bugs like Methicillin Resistant Staph Aureus
• Evolution of E.coli in long term experiments has been
ongoing since 1988, had noted a number of genetic
alterations and adaptations in the 12 populations it
has been studying.
Fossil record
• Lengthy fossil
record indication
slow changes in
morphology
leading to
modern species
from extinct ones
• Evolution of jaws
and arm bones
Embryology
• Large amounts of
embryological
evidence.
• Incredible
similarities in
developmental
sequence and
morphological
forms.
Biochemical Evidence
• Volumes of biochemical DNA and
other evidence linking modern species
to common ancestors.
• Pigments in photosynthesis Green
algae to plants
Domestication and animal breeding
• Domestication &
trait specific
breeding are
evolution.
• They influence
the populations
gene pool
through selective
breeding.
http://www.bing.com/videos/search?q=Evolution+of+dog+from+wolve+youtube&docid=457262059
8739044&mid=B4D259B3579940C48875B4D259B3579940C48875&view=detail&FORM=VIRE7
Evolution as a Theory ?
• What is theory in Science?
What is law?
• Evolution not yet fully
understood.
• Large body of supporting
evidence for Evolution.
• EVOLUTION IS A FACT!
Evolution as a Theory
• Mechanisms of evolution still debated today
• Punctuated equilibrium vs. gradual changes
Important points on
evolution
• Is a change in the gene pool of a
population
• It effects the frequency of existing
alleles (variation) in a population to
produce changes over time
• Mutations are a source of new
variation, not the mechanism of
evolution
• Survival, Growth and Reproduction
Seriation Activity
• Put the Ford Cars into a Chronology as a table group.
• For each car relative to the next in the series name one
thing that stayed the same and one thing that changed
in the cars morphology.
• Looking at the series what trends do you notice, how
have cars evolved in the last century?
• Name at least five characteristics that define all cars
as cars.
• Name five changes that have evolved and been
passed on to the next generation of cars
Seriation Activity
• Would you say that the evolution of cars is
more gradualism or punctuated equilibrium?
Explain
• What do you think influenced the Survival
Growth and Reproduction of these traits in
cars?
• How is car evolution similar to biological
evolution? How is it different?
• Was it difficult to sort out the chronological
order based on morphology?
Car Chronology Seriation
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Car Chronology Seriation
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Car Chronology Seriation
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Car Chronology Seriation
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1896
1902
1909
1915
1922
1932
1940
1956
1965
1970
1980
1990
2010
Darwin and the development of natural
selection as a Theory for the
mechanism of evolution
• Precursors of Darwin
• Voyage of the Beagle
• Years of research and
establishing a
reputation
• Hesitancy to publish
and resistance of the
scientific community
• What was Darwin
missing?
• Support for his ideas
Darwin Stood on the Backs of
Giants
• Deep Time !!!
• Hotly debated topic in science it was the
evolution of its day
• James Hutton (1726-1797) and Charles
Lyell (1797-1875)
• Studied Geography and other natural
phenomena such as the forces of wind,
water, earthquakes and volcanoes.
• They determined that The Earth is very
old and has changed slowly over time
due to natural processes.
• 4.6 Billion years Old! – we know this
through Carbon Dating
Carl Linnaeus
• 1707-1778
• Father of Taxonomy
• Developed a classification of plants
based on sexual morphology out of the
need to classify the large number of
plants brought to Europe by the
voyages of discovery
• Deeply religious believing in a fixity of
species
• Abandoned fixity of species as
evidence mounted against it and
proposed hybridization as a
mechanism of change
Erasmus Darwin
• 1731-1802
• Erasmus Darwin was a
respected physician,
philosopher, botanist, and
naturalist.
• Suggested that competition
between individuals could lead
to changes in species.
• Charles Darwin’s grandfather
Jean Baptiste Lamarck
• 1744-1829
• Proposed a
mechanism for
evolution.
• He hypothesized
that living things
evolve through the
inheritance of
acquired
characteristics.
Thomas Malthus
• 1766-1834
• Demographer
observed that human
populations cannot
keep growing
indefinitely.
• If the birth rate
continued to exceed
the death rate,
eventually humans
would run out of living
space and food.
• Famine, disease and
war prevented endless
population growth.
Charles Darwin (1809-1882)
• Formulated a theory of evolution by natural
selection based on observations made
during his voyage on the Beagle, and of
selective breeding of farm animals, plants
and pets.
• Darwin drafted manuscripts outlining his
theory in the 1840’s but hesitated to
release them to the public.
• His most famous work On the Origin of
Species by Means of Natural Selection
was published in 1859.
Voyage on the Beagle
• At the age of 21 Charles Darwin joined the crew of the HMS Beagle
as a naturalist
• He spent five years collecting geological and biological samples of for
study these included a number of fossils from South America and the
now famous Galapagos finches
South American Fossils
• Darwin studied
fossils he found
in South
America
specifically
Megatherium
comparing it to
modern Sloth's
and Armadillos
Sloth Evolution
Darwin’s Finches
• Galapagos Finches varies from island to island and
the variations seemed to correspond to food
availability on the islands
• Each population held much in common with each
other and the mainland finches he had collected.
Home again
• After returning home he spent a number of
years compiling the data he had collected
on his trip
• 1838 read the work of Thomas Malthus
• 1842 and 1844 wrote two manuscripts
outlining his theory of evolution by natural
selection.
• Worked on the classification of barnacles
and developed his reputation as a good
scientist through this meticulous work.
Hybrids Assignment
• What are they?
• Research an example of a hybrid
• Write or type a paragraph about your
hybrid
• http://poultry.allotment.org.uk/breeds/hybri
d-or-pure/hybrid-chickens
• http://www.youtube.com/watch?v=W0KOm
A0VWJo
Darwin’s Survival of the Fittest
Key Points
• Overproduction: more offspring are
produced by an organism than can
possibly survive
• Competition: high birth rates cause
a shortage of life’s necessities
leading to competition between
organisms
• Variation: each individual differs
from all other members of its
species
Darwin’s Survival of the Fittest
Key Points
• Adaptation: organisms to become
better suited to their environment
• Natural selection: the most fit (best
adapted) organisms survive to grow,
and reproduce
• Speciation: formation of new
species from ancestral species
Refusal to Publish
• Fear of public humiliation and rejection by
the scientific community of the day due to
the controversial nature of his ideas.
• Knew of 2 major problems he knew about
in his theory.
• 1) He was unable to explain the origin of
the variation within populations that natural
selection acted upon.
• 2) The mechanism of the transmission of
variation from one generation to the next
was unknown. (He was missing Mendel’s pieces)
Alfred Russell Wallace
• 1823-1913
• Proposed a theory of evolution by
natural selection similar to that of
Darwin.
• Wrote a letter and sent it to Darwin
and other scholars to review. This
spurred Darwin to finally agree to the
release of his theory.
• In 1858 Charles Lyell presented
Darwin’s 1844 essay and Wallace’s
paper to the public.
Thomas Huxley (1825-1895)
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Darwin’s Bull dog
Botanist, and anatomist
Firmly Backed Darwin’s theory
1860 debate with Samuel
Wilberforce was a turning point
in the acceptance of Darwin's
theories
• Coined the term Agnostic
6 Key points of Darwin's
Theory?
I. Overproduction
II. Competition
III. Variation
IV. Adaptation
V. Natural Selection
VI. Speciation
Overproduction
• All species produce more offspring
than can possibly survive.
• All organisms must have space
and resources for survival.
• Not all offspring will meet these
needs.
• For the next generation to continue
the species, enough individuals
must survive to reproduce.
Competition
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High birth rates cause necessary resources for
life are in short supply.
Competition between organisms for resources is
the result
Intra Specific = Competition is within a single
species
Inter Specific = Competition is between species
Variation
• All populations contain a
natural variation between
individuals (just look around
the room)
• This is less in species that
reproduce asexually
• Variations in species arises
from mutations in DNA
(creates new alleles)
• Mutations arise randomly and
are not goal directed, but may
change both structure and
function in an organisms
morphology.
Adaptation
• Organisms (populations) become
better suited to their environment
over time.
• Because the environment changes
present organisms are often best
suited to past environments
• Environmental factors filter heritable
variations, causing adaptations
(favorable variations) to accrue
through generations.
Camouflage as an adaptation
• Insect Camouflage
• http://www.cals.ncsu.edu/course/ent425/tut
orial/Ecology/camo/index.htm
Natural Selection
• Individuals with favorable heritable
adaptations gain greater advantages
(S.G.R)
• These individuals due to their
greater “fitness” tend to produce
more offspring
• Over time Nature selects for
advantageous adaptations and they
come to dominate in the populations
variation
Speciation
• Given enough time
new species will
form from earlier
ones on the basis of
natural selection
and reproductive
isolation
• .
Questions for Discussion and
Presentation
1. How does the biological definition of evolution differ from a
more general definition of evolution? What are a few of the
observable phenomenon that give evidence for evolution?
2. What is factual about evolution and what is theory? What
does theory mean in Science vs. a scientific law?
3. Name 3 Individuals who influenced Darwin’s theories and
what they theorized? How did their theories influence
Darwin?
4. Name the 6 key points of Darwin’s theory and explain how
they can lead to new species? (as best you can we will
cover this in more detail)
Mimic Octopus
• http://www.videobash.com/v
ideo_show/mimic-octopus5981
Adaptations and Fitness
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There are 3 types of adaptations
Behavioral
Physiological
Structural
These adaptations increase the Fitness of the individual
giving advantages in S.G.R
• Over generations these advantages can lead to new
different populations, that may given enough time lead to
speciation
Structural
• Refers to all adaptations that effect the arrangement of
the physical features of an organism
• Blow holes on whales and dolphins
• Loss of Ears in Seals
• The Carotid Rete
of the Oryx
• Gills, Teeth , Jaws, Limbs
• Camouflage
• Mimicry
Physiological Adaptations
• Refer to all adaptations that involve Metabolic
changes in in the Organism
• Methicillin Resistant Staph Aureus
• Pesticide Resistant Bugs
• GMO Canola (human induced)
• ASA (secondary metabolite)
• Hibernation in Ground Squirrels
Behavioral Adaptations
• Refer to all adaptations that revolve around how
organisms respond to their environments
• Migrations
• Prey Selections
• Mating Rituals
• Nesting Habits
• Hibernation in Bears
and Garter Snakes
• Mimicry in in Octopus
• Deciduous Trees
Acclimatization
• When organisms becomes accustomed to
changing environmental conditions.
• It is not the product of natural selection.
• Results no change in the gene pool of the
species.
• E.g. The difference in how we feel
temperature in Spring and Fall
Natural Selection
• Natural selection acts by elimination of un-fit
individuals from the gene pool (essentially they
don’t reproduce)
• This does not mean that they could not survive
and grow to their full potential.
• Adaptation is a result of evolution
• Species that are well adapted survive to
reproduce.
• Natural selection acts only on existing Variations
and in no way leads to perfect species.
Natural Selection leads to two
main types of evolution
• Micro-Evolution
Changes within
a species over
time
Macro-Evolution
• Changes over long periods of time
that result in new species
Examples of How Natural Selection
Leads to New Populations
• Industrial Melanism
• Pesticide Resistant Insects
• Antibiotic Resistant Bacteria
Industrial Melanism
• H.B Kettlewell studied the changes in the Peppered
Moth populations in the UK During the Industrial
revolution.
• He noted that there was a shift in the variation in
the populations coloring based on changes to their
habitat from the burning of coal in factories nearby.
Pesticide Resistant Insects
• Resistant Insects have a
genetic mutation that
inhibits the pesticides
action on them allowing
them to survive
• Only the survivors
contribute to the next
generation so all are
resistant
• Pesticide refuges are a
proposed solution to slow
the development of
resistant bugs
Natural Selection Vs Artificial
Selection
Natural Selection.
• Environmental
factors select
what adaptations
are favorable
• Tends to be slow
except in cases if
catastrophes
Artificial Selection
• Humans select for
specific traits
• Usually based on
Inbreeding
• Rapid Change (relative
to generational length)
• Like a catastrophe with
every generation
Hardy Weinberg and Genetic
Equilibrium
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Hardy Weinberg Equation
p2+2pq+q2 = 1
p = Proportion of dominant allele
q = Proportion of recessive allele
If the equation is equal to 1 NO
evolution is occurring
• This means that a population is in
Genetic Equilibrium
Conditions For Genetic
Equilibrium
1. No Mutation (new alleles)
2. No Immigration into or out of the
population
3. Population is Too Big to be affected by
random chance
4. All reproduction is totally random
5. All forms of the allele must reproduce
equally ( no reproductive advantage)
Note: all are in reference to a single trait
Conditions That Can Alter a Gene
Pool
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Natural selection
Non-Random Mating
Immigration/Emmigration
Genetic Drift, Bottle Necks and Founders
Effects
• Mutations
Divergent and
Convergent
Evolution:
Divergent evolution
• AKA Adaptive Radiation
• The process in which an ancestral species
gives rise to a number of new species that are
adapted to different environmental conditions.
• Occurs when a species colonizes a new
environment.
• Unoccupied ecological niches are filled
• Or other species are pushed out of at least
some part of their niche.
• We will come back to this!
Convergent evolution
• The process in which different organisms that
live in similar habitats become more alike in
appearance and behavior.
• Due to similar environmental pressures,
analogous structures (functionally similar
adaptations) develop in different species.
• Species that have similar structures due to
retention from a common ancestor, have
homologous structures.
• For example…
Analogous or Homologous?
Analogous or Homologous?
Analogous or Homologous?
Analogous or Homologous?
Analogous or Homologous?
Analogous or Homologous?
Analogous or Homologous?
Analogous or Homologous?
Analogous and Homologous
Analogous or Homologous?
Unit Test Friday
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Definitions, Theory Vs. Fact (evidence)
People and their contributions
Darwin's Key points
Adaptations vs. Acclimatization
How survival of the fittest acts on populations
Analogy vs. Homology
• p
Debate Questions
• Do you think humans should be manipulating
the genetics of organisms for out benefits?
GMO and Domestication
• Should we use antibacterial paints in
hospitals?
• Do you think We should continue to remove
jungles for agriculture? consider the
biodiversity and its benefits (antibiotics and
drugs) vs. the need for food for humans