Ch. 12 Evolution & Ch. 13 Adaptation & Speciation
Unit 10: Evolution Ch. 12 Evolution & Ch. 13 Adaptation &
Speciation The Most Astounding FactDr. Neil DeGrasse Tyson 300
History of Earth How old is Earth? What was early Earth like?
~4.6 billion years old What was early Earth like? hostile...a lot
of volcanic activity & lightning,many meteorite impacts,high
levels of UV light What gases were in the primitive atmosphere?
methane, ammonia, hydrogen, water vapor What gas was missing?
oxygen Alexander Oparin1936: proposed primitive atmosphere
contained: methane, ammonia, hydrogen, water vapor Whats missing?
oxygen Origin of Life When did life 1st appear?
~3.5 billion years ago What did Miller & Urey do in their
experiment? simulated primitive atmosphere & zapped it with
electricity What happened? ~1 week amino acids & other simple
organic molecules formed (in water) precursors to 1st cells 1953
electricity (similar to lightning in atmosphere) water (similar to
ocean)! The First Organisms: Heterotrophs
What does the Heterotroph Hypothesis or Primordial Soup Hypothesis
state? simple compounds formed 1st complex compounds primitive
pre-cells prokaryotes (1st cells were heterotrophs) Why
heterotrophic? b/c no O2 for cellular respiration What did they
feed on? naturally organic material (primordial soup) in ocean (ex.
amino acids) Similar to some present-day bacteria, they obtained
energy from simple chemical reactions. heterotrophs (could not
produce their own food) Why not?Used chem in surroundings for
energy no oxygen for cellular respiration, which would be used to
break the bonds in glucose made during psyn instead fed on the
organic material from the primordial soup (in oceans); give this
theory its name As a group, these bacteria are calledheterotrophic
anaerobes(ann-air-robes). Because there was virtually no oxygen in
the atmosphere at this time, these bacteria were necessarily
anaerobic, meaning they did not breathe oxygen.Heterotrophs,
meaning "other feeders", are simply organisms that cannot make
their own food. So "heterotrophic anaerobes" means they were
creatures which ate some naturally occurring food and did not
breathe oxygen. Thefossilsof some these oldest known forms of life
have been found in Australian rocks dating back 3.5 billion
years.To create energy, these early bacteria probably consumed
naturally occurring amino acids. Later Organisms: Autotrophs
What type of organisms followed the prokaryotic heterotrophs?
prokaryotic autotrophs What did they release into the atmosphere?
oxygen (.causing the oxygen revolution!) Why was oxygen so
important? allowed development of eukaryotes & complex
organisms stromatolites Stromatolites are the oldest known fossils,
dating back more than 3 billion years. They are colonial structures
formed by photosynthesizing cyanobacteria and other microbes.
Stromatolites are autotrophic prokaryotes that thrived in warm
aquatic environments and built reefs much the same way as coral
does today. Cyanobacteria were likely responsible for the creation
of earth's oxygen atmosphere. They were the dominant life form on
Earth for over 2 billion years. Today they are nearly extinct,
living a precarious existence in only a few localities worldwide
What is Evolution? theory that species/populations change over
time
Can an individuals genes change? No Can a populations gene pool
(total genes) change? Yes when allele frequencies (%) change due to
natural selection Scientific theories are explanations that are
based on lines of evidence, enable valid predictions, and have been
tested in many ways. Evolution does not explain the origin of life,
only how it changed once it got here. Gene pool: the entire
collection of genes among a populationEach new offspring in a
population draws its genes from the same gene pool. Allele
frequencies % of an allele in a population (determines frequencies
of genotypes & phenotypes in populations) EVOLUTION does not
occur w/ a purpose certain features are not developed in order to
adapt to change in env. Variation exists in population (usually due
to random mutation &/or sexual reproduction) & certain
variations become useful when env changes the organisms w/ the
best-suited variations survive & produce offspring while others
dies before they can reproduce in this way a population/species
becomes adapted to its environment 4 Mechanisms (Causes) of
Evolution
1.How does migration cause evolution? gene frequencies change as
individuals move in or out of the population 2. How does genetic
drift cause evolution? pure CHANCE causes a change in gene pool of
a small population Mechanisms methods/means by which evolution
occurs genetic drift, a change in the gene pool of a small
population that takes place strictly by chance Migration Some
individuals from a population of brown beetles might have joined a
population of green beetles. That would make genes for brown
coloration more frequent in the green beetle population than they
were before the brown beetles migrated into it. Genetic drift
Imagine that in one generation, two brown beetles happened to have
four offspring survive to reproduce. Several green beetles were
killed when someone stepped on them and had no offspring. The next
generation would have a few more brown beetles than the previous
generation but just by chance. These chance changes from generation
to generation are known as genetic drift. 4 Mechanisms of
Evolution
3. How does mutation cause evolution? random changes in DNA
sequence can change amino acid sequence & protein coded for
& can change how the trait is expressed Do all mutations matter
in evolution? No to matter they must be in gametes able to be
passed down (heritable) Mechanisms methods/means by which evolution
occurs genetic drift, a change in the gene pool of a small
population that takes place strictly by chance Mutation could cause
parents with genes for bright green coloration to have offspring
with a gene for brown coloration. That would make genes for brown
coloration more frequent in the population than they were before
the mutation. 4 Mechanisms of Evolution
4. How does natural selection cause evolution? organisms with the
variation best suited for environment (adaptation) tend to survive,
& reproduce more (survival of the fittest) What will that
cause? favorable adaptation will be passed to more offspring than
before acts on individuals, BUT causes evolution of population
Mechanisms methods/means by which evolution occurs genetic drift, a
change in the gene pool of a small population that takes place
strictly by chance Which trait was a better adaptation and selected
for? How were frequencies of different alleles affected? Natural
selection Imagine that green beetles are easier for birds to spot
(and hence, eat). Brown beetles are a little more likely to survive
to produce offspring. They pass their genes for brown coloration on
to their offspring. So in the next generation, brown beetles are
more common than in the previous generation. Example of Natural
Selection Pepper Moths EnglandOriginal color 99% white (trees light
bark)Industrial Revolution, 1850s produced smog Enviro. changes s
-99% black (trees dark bark) 4 Mechanisms of Evolution
Which trait was a better adaptation and selected for? Mechanisms
methods/means by which evolution occurs genetic drift, a change in
the gene pool of a small population that takes place strictly by
chance Which trait was a better adaptation and selected for?How
were frequencies of different alleles affected? Natural selection
Imagine that green beetles are easier for birds to spot (and hence,
eat). Brown beetles are a little more likely to survive to produce
offspring. They pass their genes for brown coloration on to their
offspring. So in the next generation, brown beetles are more common
than in the previous generation. Example of Natural Selection
Pepper Moths EnglandOriginal color 99% white (trees light
bark)Industrial Revolution, 1850s produced smog Enviro. changes s
-99% black (trees dark bark) How were frequencies of different
alleles affected? Explanations for How Evolution Happens
What did Jean Baptist Lamarck propose about how evolution occurred?
Theory of Acquired Characteristics (use vs. disuse) acquired traits
are passed on & leads to changes in species Proposed that
nature drove organisms from simple to increasingly complex forms
Did experimentation support Lamarcks thinking? no Proclaimed that
all species, including our own, are descended from other species
Inheritance of Acquired characteristicsthought that modifications
acquired during the life of an organism could be passed on to
offspringClassic example long neck of the giraffe could acquire
longer necks by reaching for leaves on higher branches & would
pass this characteristics on to their offspringEx. Tattoo would be
passed on. Also proposed use vs. disuseOrgans became stronger with
use Changes due to use or disuse could be then transferred to
offspringBody parts used extensively to cope w/ environment became
larger & stronger, while those not used deteriorated This sort
of evolution, for which Lamarck is most famous today, was only one
of two mechanisms he proposed. As organisms adapted to their
surroundings, nature also drove them inexorably upward from simple
forms to increasingly complex ones. Explanations for How Evolution
Happens
Charles Darwin (naturalist on HMS Beagle) What did he do on his
trip? collected fossils & specimens observed tremendous
biodiversity noticed unique organisms similar to organisms in other
parts of world determined they were all related desert large
rainfall intermediate shell domed Shell saddle- backed shell
Climate varied from island to island. Charles Darwin ( )naturalist
on HMS Beagle (1831-6) noticed unique organisms that were similar
to organisms in other parts of the worldDarwin determined that
these organisms were all relatedFormulated his idea of Descent with
Modification (changes occur from one group of descendants to the
next) organismsthat are adapted to their environments must also
change to remain adapted Saddlebacklong neck, curved shell, found
on Hood Island, Dome-shapedshorter neck, domed shell, lush
vegetation, covers the ground, Isabela island Explanations for
Evolution
What did Darwin conclude from his observations? life forms can
& do change. but, questioned how this change occurred answers
pointed to evolution or descent with modification needed to test
ideas before explaining how or why such changes happen Studied
Charles Lyell geologist The present is the key to the past.The same
forces acting on earth in the past are continuing today. Clear to
Darwin that organisms adapted to their environments must also
change to remain adapted. Animals and plants were well adapted to
different environments of diff islands! Questioned how this change
occurred ~answers pointed to evolution or descent with modification
(structural or functional changes occur from one group of
descendents to the next)Darwin envisioned the tree of life
Phylogenetic Tree Explanations for Evolution
When thinking about HOW evolution happened, Darwin noted artificial
selection (selective breeding) plan/goal = to produce preferred
offspring Darwin wondered, Is there a force in nature that
simulates artificial selection??? Choose parents w/ desired traits
to breed together Darwin reasoned that if we could artificially
select traits, then the same process should occur naturally
Evolution is different b/c relies on variation & chance w/o
human interference Darwins Explanation: Natural Selection
What were the 4 main points Darwin used to explain how evolution
occurred? Overproduction of offspring Struggle to survive
(competition for existence) Variation within population Successful
reproduction (survival of the fittest/ best adapted organisms are
naturally selected) 1859 Trick to remember Overproduced variations
struggle to successfully reproduce In his book On the Origin of
Species by Means of Natural Selection (1859) Darwin explained
how/why changes in populations occurred By early 1840s Darwin
developed major features of theory of natural selection as
mechanism for evolution. Reluctant to publish, continued to compile
evidence1858, Alfred Wallace, naturalist working in East Indies,
sent Darwin manuscript containing a theory of natural selection
essentially identical to Darwins.Did not know Darwin had been
developing a theory of the process behind evolutionLater that year,
both Wallaces paper and extracts of Darwins essay were presented to
the Linnaean Society of London.Darwin quickly finished The Origin
of Species and published it the next year.While both Darwin and
Wallace developed similar ideas independently, the essence of
evolution by natural selection is attributed to Darwin because he
developed and supported the theory of natural selection earlier and
much more extensively. Video:Who Was Charles Darwin? Darwins
Explanation: Natural Selection
Overproduction of offspring Why is this necessary? to ensure that
at least some offspring will survive long enough to reproduce &
pass on genes Upon his return from England Darwin read an essay by
Thomas Malthus.Malthus warns that the human population is
increasing too quickly for the planet.Larger the population gets
larger the rate of reproduction W/ pop growth comes
competitionMalthusconcludes dont worry it will fix itself!How?/Why?
Overproduction many offspring produced die before reaching maturity
due to competition for scarce resources, illness, starvation, etc.
How would these ideas have influenced Darwins thinking?Darwin
extended idea to other organisms.realized struggle for
existence/competitionSurvivors usually those best suited for
environment (fittest) Darwins Explanation: Natural Selection
Over production leads to the struggle to survive How? more
organisms than resources to go around leads to competition (idea
based on work of Thomas Malthus) Organisms compete for? food,
shelter, mates, space, light, water, nutrients, etc. Population
levels off at the carrying capacity. maximum # that can be
supported given available resources Video: Darwin & Malthus
a.k.a. struggle for existence Survivors Who are they? Individuals
w/ variations for traits adaptive for their environment that time)
have a better chance of survival, & thus, leave more offspring
How did they get these traits? By chance. (usually due to random
mutation &/or sexual reproduction) Were these traits a response
to their environment? NO certain features are NOT developed in
order to adapt to changes in the envit just so happens that certain
variations become useful when env changes The carrying capacity of
a biological species in an environment is the maximum population
size of the species that the environment can sustain indefinitely,
given the food, habitat, water and other necessities available in
the environment. Upon his return from England Darwin read an essay
by Thomas MalthusMalthus warns that the human population is
increasing too quickly for the planet.Larger the population gets
larger the rate of reproduction W/ pop growth comes
competitionMalthusconcludes dont worry it will fix itself!How?/Why?
Overproduction many offspring produced die before reaching maturity
due to competition for scarce resources, illness, starvation, etc.
How would these ideas have influenced Darwins thinking?Darwin
extended idea to other organisms.realized struggle for
existence/competitionSurvivors usually those best suited for
environment (fittest) Darwins Explanation: Natural Selection
The survivors of the struggle to survive Who are they? individuals
w/ variations that are best suited for that particular environment
(adaptations) How do they get these traits? chance & variation
unlike artificial selection which has plan/goal Were these traits a
response to their environment? NO it just so happens that the
variation is beneficial & allows for increased survival &
reproduction of more offspring with that trait (due to natural
selection for that trait) camouflage a.k.a. struggle for existence
Survivors Who are they? Individuals w/ variations for traits
adaptive for their environment that time) have a better chance of
survival, & thus, leave more offspring How did they get these
traits? By chance. (usually due to random mutation &/or sexual
reproduction) Were these traits a response to their environment? NO
certain features are NOT developed in order to adapt to changes in
the envit just so happens that certain variations become useful
when env changes The carrying capacity of a biological species in
an environment is the maximum population size of the species that
the environment can sustain indefinitely, given the food, habitat,
water and other necessities available in the environment. Upon his
return from England Darwin read an essay by Thomas Malthus.Malthus
warns that the human population is increasing too quickly for the
planet.Larger the population gets larger the rate of reproduction
W/ pop growth comes competitionMalthusconcludes dont worry it will
fix itself!How?/Why? Overproduction many offspring produced die
before reaching maturity due to competition for scarce resources,
illness, starvation, etc. How would these ideas have influenced
Darwins thinking?Darwin extended idea to other organisms.realized
struggle for existence/competitionSurvivors usually those best
suited for environment (fittest) Darwins Explanation: Natural
Selection
Variations can be adaptations. traits that make an organism better
able to survive in its environment Ex. Desert adaptations for temp
extremes & water availability EVOLUTION does not occur w/ a
purpose certain features are not developed in order to adapt to
change in env. Variation exists in population (usually due to
random mutation &/or sexual reproduction) & certain
variations become useful when env changes the organisms w/ the
best-suited variations survive & produce offspring while others
dies before they can reproduce in this way a population/species
becomes adapted to its environment BRIDGING THE GAP in teachers
edition of 200 book How do you explain a dark mouse producing
offspring that are light? GENES control mouse color thus, a certain
gene combo in offspring can result in light color (genetic
variation) Can the dark mouse control the type of color in its
offspring? NO, the sorting out of traits is a random event
occurring during meiosis Darwins Explanation: Natural
Selection
Contractile Vacuole Video Variations can be adaptations. traits
that make an organism better able to survive in its environment Ex.
Desert adaptations for temp extremes & water availability
EVOLUTION does not occur w/ a purpose certain features are not
developed in order to adapt to change in env. Variation exists in
population (usually due to random mutation &/or sexual
reproduction) & certain variations become useful when env
changes the organisms w/ the best-suited variations survive &
produce offspring while others dies before they can reproduce in
this way a population/species becomes adapted to its environment
BRIDGING THE GAP in teachers edition of 200 book How do you explain
a dark mouse producing offspring that are light? GENES control
mouse color thus, a certain gene combo in offspring can result in
light color (genetic variation) Can the dark mouse control the type
of color in its offspring? NO, the sorting out of traits is a
random event occurring during meiosis Darwins Explanation: Natural
Selection
In any given population, there will be a variation within a trait.
What causes variety? Sexual reproduction b/c combining genes from 2
genetically different parents speeds up evol b/c increase genetic
variety Crossing over during meiosis causes new arrangement of
genes on chromosomes Arrangement of chromosomes (alleles) during
meiosis affects how chromosomes sort into gametes Mutations random
changes in genes Variation exists among all groups of
organisms.Individuals w/ variations for traits adaptive for their
environment have a better chance of survival, & thus, leave
more offspring b/c variations can be inherited, many offspring will
have those same traits Organisms lacking those traits are less
likely to survive & tend to leave fewer offspring over time,
the population consists only of adapted organisms (until
environment changes) What we know about genetics today supports
Darwins theory of natural selection Darwins Explanation: Natural
Selection
What causes variations within a population? Sexual reproduction
Crossing over during meiosis Arrangement of chromosomes during
meiosis (independent assortment) Mutations Sexual repro. &
meiosis speed up evolution increases variety Darwin did NOT have
knowledge of genetics! What causes variety? Sexual reproduction b/c
combining genes from 2 genetically different parents speeds up evol
b/c increase genetic variety Crossing over during meiosis causes
new arrangement of genes on chromosomes Arrangement of chromosomes
(alleles) during meiosis affects how chromosomes sort into gametes
Mutations random changes in genes Variation exists among all groups
of organisms.Individuals w/ variations for traits adaptive for
their environment have a better chance of survival, & thus,
leave more offspring b/c variations can be inherited, many
offspring will have those same traits Organisms lacking those
traits are less likely to survive & tend to leave fewer
offspring over time, the population consists only of adapted
organisms (until environment changes) What we know about genetics
today supports Darwins theory of natural selection Darwins
Explanation: Natural Selection
How does natural selection lead to successful reproduction? Those
organisms best suited for environment tend to survive, reproduce,
& pass on genes (survival of fittest) more offspring have
favorable adaptation than before Example of Natural Selection
Pepper Moths EnglandOriginal color 99% white (trees light
bark)Industrial Revolution, 1850s produced smog Enviro. changes s
-99% black (trees dark bark) Darwins Explanation: Natural
Selection
Ex. Pepper Moths England Original color 99% white (trees w/ light
bark) Industrial Revolution, 1850s produced soot Enviro. changes s
-99% black (trees w/ dark bark) Pepper Moth Game Principles of
Natural Selection "Interactive" Darwins Explanation: Natural
Selection Divergent evolution Finches on different islands ate
different foods beak adaptations that helped them gain more food
(& thus survive & reproduce) were selected for & passed
on to offspring. Eventually causing adaptive radiation so that
birds on different islands had beaks that were more suited to the
type of food available on that island (other beak types that were
not well adapted to that food type were selected against) Adaptive
Radiation Hawaiian Honeycreepers Divergent evolution How would
Darwin adjust the description given by Lamarck about the length of
giraffes necks?
Lamarck vs. Darwin Darwin would say that its not b/c the giraffe
keeps stretching that necks get longer over time, but that within
the population, there is variation in neck length & that those
giraffes w/ longer necks are better suited to their env &
getting food off the tops of trees. Therefore, they are able to
survive better, reproduce more, & pass on their genes (compared
to those w/ short necks) over time, more individuals have the genes
for longer necks b/c selected for (due to successful reproduction)
Darwins Explanation: Wallaces Same Conclusion
Who was Alfred Wallace (1858)? naturalist that arrived at same
basic explanation as Darwin However, Darwin usually given credit
but BOTH men should be credited By early 1840s Darwin developed
major features of theory of natural selection as mechanism for
evolution. Reluctant to publish, continued to compile evidence
1858, Alfred Wallace, naturalist working in East Indies, sent
Darwin manuscript containing a theory of natural selection
essentially identical to Darwins.Did not know Darwin had been
developing a theory of the process behind evolutionLater that year,
both Wallaces paper and extracts of Darwins essay were presented to
the Linnaean Society of London.Darwin quickly finished On the
Origin of Species and published it the next year.While both Darwin
and Wallace developed similar ideas independently, the essence of
evolution by natural selection is attributed to Darwin because he
developed and supported the theory of natural selection earlier and
much more extensively. Indirect Evidence to Support the Theory of
Evolution: Fossil Record
evidence of: change in organisms over time age of the Earth Which
layer is youngest? oldest? Explain Law of Superposition Indirect
dont/cant actually see happening generally happens over very long
periods Direct see happening. Generally can happen w/in a few
generations/a persons lifetime Fossils once living remains of
organisms traces or impressions of organisms from the past,
mineralized in sedimentary rocks Fossils w/in layers show that a
succession of organisms have populated Earth throughout time.
Evidence of change over timetypes of organisms change from one
layer to the next in general, simpler body structures found in
older layers & more complex structures found in younger/more
recent layers However, many of the simpler life forms still exist
Fossil record is limited b/c Decomposition often occurs rapidlyto
be fossilized must be covered in sediment as quickly as possible
(this is why more fossils of shells & aquatic
organisms)Exceptions frozen, dried, anoxic environment
fossilization is affected by type of material preserved (bone,
shell, impressions, amber) hard parts preserve better 3. Fossil
record is incompleteWhy? b/c not all organisms are fossilized, not
all fossils are found 4. Easily disrupted Why? some are destroyed
by nature/people. Principle of original horizontality (sedimentary)
rock layers deposited horizontally & stay that way unless
disrupted by outside force Law of superpositionNicolaus Steno layer
on bottom was deposited 1st as move up, layers become younger
youngest layer on top Correlation matching up of layers &
fossils (ex. across river..) Indirect Evidence to Support the
Theory of Evolution: Fossil Record
Why is the fossil record limited? decomposition type of material
What fossilizes best? hard parts. teeth, bones, scales incomplete
record Why? not all organisms are fossilized not all fossils are
found easily disrupted some are destroyed by natural processes or
people Indirect dont/cant actually see happening generally happens
over very long periods Direct see happening. Generally can happen
w/in a few generations/a persons lifetime Fossils once living
remains of organisms traces or impressions of organisms from the
past, mineralized in sedimentary rocks Fossils w/in layers show
that a succession of organisms have populated Earth throughout
time. Evidence of change over timetypes of organisms change from
one layer to the next in general, simpler body structures found in
older layers & more complex structures found in younger/more
recent layers However, many of the simpler life forms still exist
Fossil record is limited b/c Decomposition often occurs rapidlyto
be fossilized must be covered in sediment as quickly as possible
(this is why more fossils of shells & aquatic
organisms)Exceptions frozen, dried, anoxic environment
fossilization is affected by type of material preserved (bone,
shell, impressions, amber) hard parts preserve better 3. Fossil
record is incompleteWhy? b/c not all organisms are fossilized, not
all fossils are found 4. Easily disrupted Why? some are destroyed
by nature/people. Principle of original horizontality (sedimentary)
rock layers deposited horizontally & stay that way unless
disrupted by outside force Law of superpositionNicolaus Steno layer
on bottom was deposited 1st as move up, layers become younger
youngest layer on top Correlation matching up of layers &
fossils (ex. across river..) Indirect Evidence to Support theTheory
of Evolution: Comparative Anatomy
compares structures of different organisms living today homologous
structures analogous structures vestigial structures Indirect
dont/cant actually see happening generally happens over very long
periods Direct see happening. Generally can happen w/in a few
generations/a persons lifetime Indirect Evidence to Support
theTheory of Evolution: Comparative Anatomy
1. What are homologous structures? similar structures with
modifications (ex. location & arrangement of bones) Which are
evidence of ? a common ancestor later organisms becoming more
different (divergent evolution) Indirect dont/cant actually see
happening generally happens over very long periods Direct see
happening. Generally can happen w/in a few generations/a persons
lifetime Homologous Structures Parts on different organisms that
are similar in structure w/ some variations/modifications (and
often similar function) and seem to indicate common origin common
ancestor.Ex. bones of arm, wing, fin, & foreleg. Indicate
divergent evolution things becoming more different. 2. What are
analogous structures?
Indirect Evidence to Support theTheory of Evolution: Comparative
Anatomy 2.What are analogous structures? different structure, but
same function (ex. wings made of different materials bird = bone
vs. insect = chitin) Which are due to? similar environment/use but
do NOT have common ancestor later organisms become more similar
(convergent evolution) Indirect dont/cant actually see happening
generally happens over very long periods Direct see happening.
Generally can happen w/in a few generations/a persons lifetime
Unrelated organisms look similar b/c of common environmental
conditions, but structure itself is different Ex. wing of bird has
bones, wing of insect does not, but both are used for flight
becoming more similar due to convergent evolution (b/c similar
environment/use) Indirect Evidence to Support theTheory of
Evolution: Comparative Anatomy
3. What are vestigial structures? structures with reduced size or
function that often have no apparent use Which are evidence that?
species has changed Indirect dont/cant actually see happening
generally happens over very long periods Direct see happening.
Generally can happen w/in a few generations/a persons lifetime How
does embryonic development provide evidence for evolution?
Indirect Evidence to Support theTheory of Evolution: Comparative
Embryology How does embryonic development provide evidence for
evolution? early stages very similar later stages more distinction
What does this tell us? organisms inherited same basic body plan
from common ancestor greater # similar stages more closely related
Indirect dont/cant actually see happening generally happens over
very long periods Direct see happening. Generally can happen w/in a
few generations/a persons lifetime Pic. Fish, salamander, tortoise,
chick hog, cat, rabbit, human (all mammals) Indirect Evidence to
Support theTheory of Evolution: Comparative Biochemistry
What codes for similar organic compounds (ex. amino acids &
proteins)? similar DNA DNA most reliable form of evidence What is
the significance of 2 very different speciessharing large amounts
of the same DNA? evidence of common ancestry higher %, more closely
related Indirect dont/cant actually see happening generally happens
over very long periods Direct see happening. Generally can happen
w/in a few generations/a persons lifetime Hemoglobin protein in red
blood cells that carries oxygen Cytochrome c is a protein used in
cellular respiration Phylogeny = Evolutionary history of a living
organism based on such factors such as fossil evidence &
biochemical comparisons Relationships shown through phylogenetic
tree Direct Evidence to Support the Theory of Evolution:
Observation
Ex. of rapid evolution that allow us to observe evolution?
antibiotic- resistant bacteria MRSA pesticide-resistant insects
Resistance already present in some individuals (variation)
resulting from mutation Indirect dont/cant actually see happening
generally happens over very long periods Direct see happening.
Generally can happen w/in a few generations/a persons lifetime
rapid usually within a few decades (seen w/in a humans lifetime)
antibiotic resistant bacteria MRSA (Methicillin-resistant
Staphylococcus aureus) Evolution & Classification
Evolutionary relationships are the basis of classification closely
related share more groups (similar classification) black bear &
brown bear same down to genus distantly related share fewer groups
(dissimilar classification) snake & brown bear same only to
phylum DOMAINEukaryota from Domain down, each level has a new set
of criteria that must be shared Ex in pic. Domain all have nucleus,
kingdom all are animals (have nucleus AND multicellular
heterotrophs that do not have cell walls), phylum all have
spines/backbones (and are animals with have nucleus AND
multicellular heterotrophs that do not have cell walls), class all
give birth to live young, feed the young milk, are covered w/ fur,
have mammary glands (AND have spines/backbones (and are animals
with have nucleus AND multicellular heterotrophs that do not have
cell walls). Order eat meat. AND.. Every characteristic from
above