Download evolution

Unit 12: Evolutionary Processes
Mr. Nagel
Meade High School
IB Syllabus Statements
• 5.4.1
– Define evolution.
• 5.4.8
– Explain two examples of evolution in
response to environmental change; one
must be antibiotic resistance in bacteria.
• http://click4biology.info/c4b/5/eco5.4.htm
Think…
• What is meant by the word ‘evolution’?
• What other words come to mind when you
hear the word ‘evolution’?
History of Understanding – Part I
• The year is 1600…
– You see what you believe to be fish coming
from mud and flies from rotting meat
– The accepted theory is spontaneous
Spontaneous generation - living
generation
organisms can arise from non-living
matter
• How could you refute this notion in 1600?
– Hint: The microscope hasn’t been invented
yet!
http://www.kent.k12.wa.us/staff/TimLynch/sci_class/chap01/spontaneous.html
History of Understanding – Part II
• Francesco Redi (1600’s)
– Where do maggots come from?
• Arise from spontaneous generation?
• Rotten meat or fly’s eggs?
History of Understanding – Part III
• Lazzaro Spallanzani (1700’s)
– Where do microorganisms come from?
• Arise from ‘vital force’ in the air?
– Nutrient baths
» sealed and unsealed
» boiled and not
– Many people felt he ‘cooked the vital force out of the air’
History of Understanding – Part IV
• Louis Pasteur (1800’s)
– Where do microorganisms come from?
• Final experiment to disprove ‘Vital Force’
– Unique glass shape traps dirt on which
cells of organisms travel
» Placed in various locations
• Ended the era of ‘Spontaneous Generation’
• Began new era: Biogenesis!
Biogenesis - theory that living
organisms come only from
other living organisms
Charles Darwin
• On the Origin of Species by Means of
Natural Selection (1859)
– Species originate through evolutionary
change
• HMS Beagle – Galapagos Islands (Finches) –
1838 [Ship:1831-1836]
• http://www.bbc.co.uk/history/historic_figure
s/darwin_charles.shtml
Your Turn! - Create a Timeline
• Include the following events, people, and ideas:
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Charles Darwin (HMS Beagle) – 1831-1836
Charles Darwin (Origin of Species) – 1859
Louis Pasteur’s Experiment – 1864
Lazzaro Spallanzani Experiment – 1767
Francesco Redi’s Experiment – 1668
Linnaeus (Classification system established) – 1735
Lamarck (Philosphie Zoologique) – 1809
Mendel’s papers published – 1866
Urey-Miller Experiment – 1952/1953
Scopes Monkey Trial – 1925
DNA puzzle solved – 1953
Human Genome project completed – 2003
Investigation: Adaptation
• http://whyfiles.org/038badbugs/
– Read about how microbes have developed
resistances to antibiotics
• Germ Warfare
• Putting up Resistance
– How can adaptations influence an organism’s
ability to survive?
IB Syllabus Statements
• 5.4.1
– Define evolution.
• 5.4.5
– State that the members of a species show variation.
• 5.4.6
– Explain how sexual reproduction promotes variation in a
species.
• 5.4.3
– State that populations tend to produce more offspring than
the environment can support.
• 5.4.4
– Explain that the consequence of the potential
overproduction of offspring is a struggle for survival.
• http://click4biology.info/c4b/5/eco5.4.htm
Define
• Evolution
• Variation
• Adaptation
Vocabulary - Review
• Evolution
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A gradual process in which something changes into a different form
• Variation
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deviation of an individual from the group to which it belongs (the
act or process of changing)
• Adaptation
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The adjustment or changes in an organism to become more suited
to an environment
Think…Pair…Share…Review
• How can new traits come about (think
sex)?
– Result from new combinations of existing
genes or from mutations of genes in
reproductive cells within a population
• How do adaptation and variation play into
this concept?
Natural Selection
• The process by which organisms best
suited to survival in their environment
achieve greater reproductive success,
thereby passing advantageous genetic
characteristics on to future generations
• How could changes in the environment
bring about natural selection?
Moths and Ind. Rev.
• Gizmo?
Survival of the Fittest
• What consequences would result from
having too many offspring?
• What natural factors would ensure that the
fittest organisms would survive?
Warmup
• What environmental pressures exist that
naturally select members of a population
to survive?
IB Syllabus Statements
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5.4.2
– Outline the evidence for evolution provided by the fossil record, selective breeding of
domesticated animals and homologous structures.
D.1.1
– Describe four processes needed for the spontaneous origin of life on Earth.
D.1.2
– Outline the experiments of Miller and Urey into the origin of organic compounds.
D.1.3
– State that comets may have delivered organic compounds to Earth.
D.1.4
– Discuss possible locations where conditions would have allowed the synthesis of
organic compounds.
D.1.5
– Outline two properties of RNA that would have allowed it to play a role in the origin of
life.
D.1.6
– State that living cells may have been preceded by protobionts, with an internal
chemical environment different from their surroundings.
D.1.7
– Outline the contribution of prokaryotes to the creation of an oxygen-rich atmosphere.
D.1.8
– Discuss the endosymbiotic theory for the origin of eukaryotes.
Video Clip
• Darwin’s Theories in Action
Brainstorm...
• What evidences have you heard of that
support evolution?
• Evolution is a Theory. What is the
difference between a theory and a law?
Evidences of Evolution
• Fossil Records
– Transitional Fossils vs. Missing Links
• Homologous Structures
– It’s all Relative
• Analogous Structures
– Function, not Origin (Wings)
• Vestigial Organs
– Useful or Designer
• Embryological Development
– Fact or Fiction
• Biochemical
– AA sequences and Cytochrome C
True Embryology
Science 1997
Twenty years from now…
• You are tasked with attempting to
terraform Mars.
– Research what factors were important in
Earth’s early days to promote simple life.
– What steps (and in what order) would you
need to execute in order to achieve success?
– What experiments/findings could substantiate
your action plan?
4A’s plan for Mars Domination
• Non-living simple organic molecules
– Amino Acids (Methane, Ammonia, Water, H2)
– Urey/Miller (presence electricity)
• Polymerization
– Heat/Energy (Volcanic activity, molten core)
• Inheritance via self-replicating molecules
– Ribozymes (RNA)
• Package inside membranes
– Prokaryotic (bacteria)  eukaryotic (algae)
Warmup
• Name three subtypes of natural selection
and provide an example of each!
Warmup
• What four processes were needed for the
spontaneous origin of life on Earth?
IB Syllabus Statements
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D.2.1
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D.2.2
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Discuss ideas on the pace of evolution, including gradualism and punctuated equilibrium.
D.2.10
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Compare convergent and divergent evolution.
D.2.9
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Outline the process of adaptive radiation.
D.2.8
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Compare allopatric and sympatric speciation.
D.2.7
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Explain how polyploidy can contribute to speciation.
D.2.6
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Describe three examples of barriers between gene pools.
D.2.5
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Discuss the definition of the term species.
D.2.4
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State that evolution involves a change in allele frequency in a population’s gene pool over a number
of generations.
D.2.3
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Define allele frequency and gene pool.
Describe one example of transient polymorphism.
D.2.11
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Describe sickle-cell anemia as an example of balanced polymorphism.
Group Research
• 1: Allele Frequency vs. Phenotypic
Frequency
• 2: Speciation and Adaptive Radiation
• 3: Geographic vs. Temporal vs. Behavioral
Isolation
• 4: Allopatric vs. Sympatric Speciation
• 5: Convergent vs. Divergent Evolution
• 6: Gradualism vs. Punctuated Equilibrium
• 7: Transient vs. Balanced Polymorphism
Group Research
• What is it?
• Examples/Illustrations?
• Why is this evolution?
Warmup
• What conditions are necessary for natural
selection to occur?
Definitions and Examples
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Gene Pool
Allele Frequency
Species
Speciation
Allopatric Speciation
Sympatric Speciation
Adaptive Radiation
Convergent Evolution
Divergent Evolution
Equilibrium
Allele Frequencies
• How many people in class are male?
Female?
• How many X chromosomes are present?
Y chromosomes?
• Note: Chromosomes != alleles.
• Large changes in allele frequency indicate
evolutionary change!
Species
• Can interbreed and produce fertile
offspring
• Similar physiological and morphological
characteristics (observed/measured)
• Genetically distinct
Speciation
• Reasons for Speciation (mainly barriers)
– Geographical
• Allopatric [physical barrier]
• Sympatric [shared area]
– Temporal
– Behavioral
• Hybridization yields infertile offspring
• Polyploidy
– Incompatibility of chromosomal sets
Adaptive Radiation
• Adaptations yield variations on one
species
– Think Finches
– Various adaptations allow a flavor of species
to survive in their own environment
– Over time, new species evolve (i.e. disruptive
selection)
Math
• What do the terms converge and diverge
mean? Physics?
Equilibrium
• Gradualism vs. Punctuated
Polymorphism
• Transient vs. Balanced
Warm Up
• Contrast panspermia with endosymbiosis.
Warm Up
• How does sexual reproduction promote
variation within a species?
IB Syllabus Statements
• 5.5.1
– Outline the binomial system of nomenclature.
• 5.5.2
– List seven levels in the hierarchy of taxa—kingdom, phylum,
class, order, family, genus and species—using an example from
two different kingdoms for each level.
• 5.5.3
– Distinguish between the following phyla of plants, using simple
external recognition features: bryophyta, filicinophyta,
coniferophyta and angiospermophyta.
• 5.5.4
– Distinguish between the following phyla of animals, using simple
external recognition features: porifera, cnidaria, platyhelminthes,
annelida, mollusca and arthropoda.
• 5.5.5
– Apply and design a key for a group of up to eight organisms.
• http://click4biology.info/c4b/5/eco5.5.htm
Taxonomy
• Linnaeus (1735)
– (D) K P C O F G S
Binomial Nomenclature
• Bi = two
– Genus (capitalized)
– Species (not capitalized)
• Should be italicized or underlined
Plant Distinctions
Phyla
Bryophyta
Filicinophyta
Coniferophyta
Angiospermophyta
Features
Animal Distinctions
Phyla
Porifera
Cnidaria
Platyhelminthes
Annelida
Mollusca
Arthropoda
Features
Dichotomous Keys
• Observed characteristics help divide
species into smaller groups
• Final step should have final identifying
name
Eight Species
Develop a key that could be used to uniquely
identify each organism, then give it to a classmate
to verify that it works.
Warm Up
Develop a key that could be used to uniquely
identify each organism, then give it to a classmate
to verify that it works.
IB Syllabus Statements
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D.3.1
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D.3.2
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Discuss the correlation between the change in diet and increase in brain size during hominid
evolution.
D.3.9
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Discuss the incompleteness of the fossil record and the resulting uncertainties about human
evolution.
D.3.8
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State that, at various stages in hominid evolution, several species may have coexisted.
D.3.7
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Outline the trends illustrated by the fossils of Ardipithecus ramidus, Australopithecus including
A. afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and
H. sapiens.
D.3.6
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Describe the major anatomical features that define humans as primates.
D.3.5
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Deduce the approximate age of materials based on a simple decay curve for a radioisotope.
D.3.4
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Define half-life.
D.3.3
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Outline the method for dating rocks and fossils using radioisotopes, with reference to 14C and 40K.
Distinguish between genetic and cultural evolution.
D.3.10
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Discuss the relative importance of genetic and cultural evolution in the recent evolution of humans.
Radioactive Dating Techniques
• Half-life: How long it takes for a
substance to radioactively decay
to half the quantity.
• 14C (biomass) and 40K (rocks)
are popular isotopes for
determining age.
• 14C = 5,730 yrs
• 40K = 1.28 x 109 yrs
• Proportion of stable daughters to
unstable parent isotopes
How old is it?
• Given the curve above, how old is the
sample (tested for 14C) if the sample has
roughly 6% 14C remaining in it?
• 14C = 5,730 yrs
• Amount = 1 / (2t½)
Research Time!
• Outline the trends illustrated by the fossils of:
• Ardipithecus ramidus
• Australopithecus
– A. afarensis
– A. africanus
• Homo
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H. habilis
H. erectus
H. neanderthalensis
H. sapiens.
Anatomical Differences
Anatomical feature
Ape-like form
Human-like form
Position of spinal
intersection with skull
Towards the back of the
skull base
Towards the center of
the skull base
Cranial Capacity
Small
Large
Canine Teeth
Long/Sharp
Short/Dull
Molars
Long/Narrow
Short/Wide
Brow Ridge
Protruding
Flat
Facial Region
Protruding
Flat
Jaw
Tall/Thick
Small and Thin
Adapted from HL Biology page 436
Hominid Evolution I
• Uncertainties: 5 million years of evolution
with only a few ‘pieces’ in the puzzle.
• Doubtful that any species interacted with
each other, even though some coexisted
on Earth at the same time. (Carbon dating)
• Increased proteins/meats in diet led to
increased brain size/energy requirements.
• DNA implies a common ancestor with
apes, but no scientist has ever proposed
being DESCENDED from monkeys.
(radiation)
Genetic vs. Cultural Evolution
• Genetic Evolution implies changes in
INHERITED CHARACTERISTICS
– Morphology
– Chromosomal Numbers
– Biochemistry (blood proteins, enzymes)
• Cultural Evolution implies changes in
ACQUIRED KNOWLEDGE
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Language
Customs and Rituals
Art
Technology
Hominid Evolution II
• As brain size increased, quality of tool
making also increased.
• Genetic evolution precedes cultural
evolution.
• In the last 30k years, H. Sapiens have
been largely cultural.
– Is this atypical?
Warm Up
• Describe the importance of changes in
allele frequency for the evolution of one
species into another.
(4 marks)
natural selective pressures result in survival of advantageous alleles;
frequency of these alleles will increase through reproduction;
these alleles spread through population;
basis for microevolution;
over time many advantageous genes accumulate in a species;
when many changes occur some members of a species
cannot successfully mate with others / reproductive isolation;
results in evolution of a new species;
IB Syllabus Statements
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D.4.1
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D.4.2
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D.4.3
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D.5.1
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D.5.7
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D.5.8
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Discuss how biochemical variations can be used as an evolutionary clock.
Define clade and cladistics.
Distinguish, with examples, between analogous and homologous characteristics.
Outline the methods used to construct cladograms and the conclusions that can be drawn from them.
Construct a simple cladogram.
D.5.9
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Explain how variations in specific molecules can indicate phylogeny.
D.5.6
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Explain the biochemical evidence provided by the universality of DNA and protein structures for the common ancestry
of living organisms.
D.5.5
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Outline the value of classifying organisms.
D.5.4
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State the assumptions made when the Hardy–Weinberg equation is used.
D.5.3
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Calculate allele, genotype and phenotype frequencies for two alleles of a gene, using the Hardy–Weinberg equation.
D.5.2
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Explain how the Hardy–Weinberg equation is derived.
Analyse cladograms in terms of phylogenetic relationships.
D.5.10
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Discuss the relationship between cladograms and the classification of living organisms.
Hardy-Weinberg
Warm Up
Warm Up Answers