Quick Review: Theory vs. Law Theory: A well-tested explanation
to make accurate predictions They can be changed! Law: A
generalized way of explaining things, but doesnt necessarily say
why Law of gravity Cant be disproven
Slide 3
Earths Early History 19.3 What do scientists hypothesize about
early Earth and the origin of life? What theory explains the origin
of eukaryotic cells? What is the evolutionary significance of
sexual reproduction?
Slide 4
The Mysteries of Lifes Origins Earth was struck by a large
object and heated Eventually cooled down enough to form oceans Its
atmosphere had very little oxygen
Slide 5
The Mysteries of Lifes Origins Miller and Ureys experiment
suggested how mixtures of organic compounds necessary for life
could have arisen Not entirely accurate more recent experiments
have been done First formations were thought to be proteinoid
microspheres that had some characteristics of living things NOT
CELLS!
Slide 6
The Mysteries of Lifes Origins RNA World hypothesis states that
RNA came before DNA do you think this is possible?
Slide 7
The Mysteries of Lifes Origins First forms of live evolved to
live in an oxygen free world anaerobic prokaryotes Eventually,
photosynthetic bacteria came around which produced _________. This
allowed aerobic organisms to evolve.
Slide 8
Origin of Eukaryotic Cells EukaryoticProkaryotic Have nucleus
Have membrane-bound organelles Have mitochondria No nucleus Very
few membrane-bound organelles
Slide 9
Origin of Eukaryotic Cells The endosymbiosis theory suggests
that a __________ relationship evolved between eukaryotes and
prokaryotes Created the mitochondria and the chloroplasts we know
today
Slide 10
Origin of Eukaryotic Cells In support of this hypothesis:
Mitochondria and chloroplasts contain their own DNA which is
similar to bacteria DNA. Have their own ribosomes Replicate like
bacteria (binary fission)
Slide 11
Sexual Reproduction Important in our evolutionary history
because it introduces genetic diversity / variation. Genetic
variation increases the likelihood of a population adapting to new
or changing environmental conditions.
Slide 12
Evidence of Evolution 16.4 How does the geographic distribution
of species today relate to their evolutionary history? How do
fossils help to document the descent of modern species from ancient
ancestors? What do homologous structures and similarities in
embryonic development suggest about the process of evolutionary
change? How can molecular biology be used to trace the process of
evolution? What does recent research on the Galapagos finches show
about natural selection?
Slide 13
Evidence of Evolution Darwin hypothesized that animals evolved
because of natural selection what is that??
Slide 14
Biogeography Patterns in the distribution of living and fossil
species tell us how modern organisms evolved from their
ancestors.
Slide 15
Biogeography Closely related but differentDistantly related but
similar Alike species with different traits Different species with
same traits (similar environment)
Slide 16
Age of Earth & Fossils Radioactive data shows Earth to be
4.5 billion years old supporting Darwins theory (lots of time for
evolution) Recent fossil records are filling the gaps, showing that
modern species evolved from extinct ancestors.
Slide 17
Comparing Anatomy & Embryology Evolutionary theory explains
the existence of homologous structures adapted to different
purposes as the result of descent with modification from a common
ancestor.
Slide 18
Comparing Anatomy & Physiology HomologousAnalogous Similar
structure Similar function
Slide 19
Comparing Anatomy & Embryology Vestigial structures arent
necessary, but dont harm the function of the organism and so they
remain Appendix!
Slide 20
Comparing Anatomy & Embryology Similar patterns of
embryological development provide further evidence that organisms
have descended from a common ancestor.
Slide 21
Genetics & Molecular Biology At the molecular level, the
universal genetic code and homologous molecules provide evidence of
common descent Most of the DNA and RNA used from bacteria to humans
is the same. We must have come from a common ancestor!
Slide 22
Genetics & Molecular Biology Homologous proteins are shared
from bacteria to humans how we make insulin from bacteria for our
use. Homologous genes exist between flies and humans these same
genes direct our head-to-tail development and limbs
Slide 23
Testing Natural Selection The Grants were able to test Darwins
hypothesis by: Analyze that there was enough heritable variation in
the traits for natural selection There were enough differences in
beak size and shape to produce differences in fitness
Slide 24
Testing Natural Selection Dry weather = more survival of large
beak birds Their data confirmed that competition and environment
drive natural selection
Slide 25
Hominine Evolution 26.3 (Pg. 767) What adaptations enabled
later hominine species to walk upright? What is the current
scientific thinking about the genus Homo?
Slide 26
Hominine Evolution We separated to create hominines and
chimpanzees The skull, neck, spinal column, hip bones, and leg
bones of early hominine species changed shape in ways that enabled
later species to walk upright bipedal.
Slide 27
Hominine Evolution Bipedal allowed us to free our hands for
tools developed opposable thumbs Also developed larger brains
(cerebrums) Figure 26-16 gives major differences between humans and
gorrillas
Slide 28
Hominine Evolution Fossils date back to 7 million years old not
all findings are ancestors, they may be relatives Research suggests
bipedalism evolved before larger brains Oldest hominine: 2002,
Sahelanthropus Best studied:1974, Australopithecus afarensis or
Lucy
Slide 29
Hominine Evolution Recent research shows our human evolution
isnt straight forward more like several branches and several trunks
Homo habilis: handy man, probably our ancestor Homo ergaster:
bigger brain, downward-facing nostrils
Slide 30
Hominine Evolution Our genus originated in Africa and migrated
from there to populate the world Homo habilis in Turkey Homo
Erectus in Asia
Slide 31
Hominine Evolution Multiregional hypothesis says we evolved
independently in various parts of the world Out-of-Africa model
suggests we migrated and colonized the rest of the world about
200,000 years ago More supported theory by mitochondrial DNA
evidence
Slide 32
Hominine Evolution Modern humans may or may not have coexisted
with Neanderthals something made Neanderthals go extinct and Homo
sapiens remain the only hominine clade. Both used stone tools,
lived in complex social groups, controlled fire, and had rituals to
bury their dead.
Slide 33
GO HEAT!!
Slide 34
The Brain (Pg. 902-903) Split into 5 major components: Cerebrum
Limbic System Thalamus and Hypothalamus Cerebellum Brain Stem
Slide 35
The Brain Cerebrum: largest region of the brain responsible for
voluntary (conscious) activities Intelligence, learning and
judgment are stored here The part that grew the most in our
ancestors
Slide 36
The Brain The Cerebrum is split up into right and left
hemispheres Left hemisphere controls right-side of the body and
vice versa Also into four lobes Frontal (planning, judgments)
Temporal (hearing and smell) Parietal (reading and speech)
Occipital (vision)
Slide 37
The Brain The Cerebrum also has two layers The cerebral cortex
(topmost layer, aka grey matter) which has many of the neurons
responsible for all the activities White matter (innermost layer)
which makes connections between different brain areas
Slide 38
The Brain Limbic System: mostly associated with emotions,
behavior, and long-term memory
Slide 39
The Brain Thalamus: receives messages from sensory neurons and
sends them to the right place Hypothalamus: helps to know and
analyze hunger, thirst, fatigue, anger, and body temperature
Slide 40
The Brain Cerebellum: second largest region of the brain which
deals with coordinating the bodys actions
Slide 41
The Brain Brain stem: the oldest part of the brain which
connects the brain to the rest of the body Also controls important
functions like blood pressure, heart rate, breathing, and
swallowing What keeps you breathing while you sleep
Slide 42
Darwins Voyage of Discovery 16.1 Darwin developed a scientific
theory of biological evolution that explains how modern organisms
evolved over long periods of time through descent from common
ancestors Darwin was born in 1809 and began his journey in 1831 on
the HMS Beagle
Slide 43
Observations Aboard The Beagle Darwin didnt just observe
species, he thought about them in scientific ways and noticed
Species vary globally Species vary locally Species vary over time
Different species inhabit separate, but ecologically similar
habitats
Slide 44
Observations Aboard The Beagle Darwin also noticed that
different, yet related animal species occupied different habitats
within a local area All his observations were conducted between
Australia, South America, and Africa (and of course, the
Galapagos)
Slide 45
Observations Aboard The Beagle Darwin also noticed that some
fossils of extinct animals were similar to living species the
Glyptodont and the Armadillo All of this evidence suggested that
species are not fixed, but that they change by some kind of natural
process which we know today as ________________.
Slide 46
Lets Practice! Find your study buddy Study Workbook A Pgs.
169-170. Question AND Answer. One sheet of paper for both of you
Skip #4
Slide 47
Ideas that shaped Darwins thinking 16.2 Hutton and Lyell, two
geologists, concluded that Earth is extremely old and the processes
that changed Earth in the past are still operating in the present
Went against the idea that Earth was only a few thousand years
old
Slide 48
An Ancient, Changing Earth Hutton introduced deep time: our
planets history is older than we can imagine. He reached this
conclusion by his observations of: The layers of rocks in
mountains, valleys, and even volcanic molten lava Rain, wind, heat
and cold take a long time to shape rock
Slide 49
An Ancient, Changing Earth Lyell believed in uniformitarianism
laws are constant over time (what happens now, happened then)
Darwin read Lyells book and observed an earthquake push rock from
the sea out if Earth was old, and the same things happened, could
life have changed too?
Slide 50
Lamarcks Evolutionary Hypothesis Lamarck suggested that species
decide what part of themselves to use / not use, and these traits
were passed on to offspring Published the year Darwin was born,
1809
Slide 51
Lamarcks Evolutionary Hypothesis He suggested that if we wanted
longer legs, we simply had to wish or stretch for them and it would
happen acquired characteristics Then, we passed then on to our
children inherited acquired characteristics Crazy ideas! But he was
the first to suggest we changed according to our environment
essential for people like Darwin to come up with evidence!
Slide 52
Population Growth Malthus had suggested that we cant grow
unchecked because there wont be enough space for everyone we were
limited by war, famine and disease Darwin linked this to other
organisms and reasoned this must be the reason why only certain
individuals survive and reproduce
Slide 53
Artificial Selection Variations cause some animals to be more
productive than others we choose the best and breed those to make
sure those variations become permanent. Darwin didnt understand
where these variations came from, but he knew this would cause
changes in the species
Slide 54
Darwin Presents His Case- 16.3 Darwin did not publish his ideas
immediately for fear of being ridiculed, until he found out Wallace
was about to publish something very similar
Slide 55
Evolution by Natural Selection The struggle for existence: more
are born than can survive, and must compete for resources Those
with the best adaptations (body part, color, function or behavior)
survive and reproduce have high fitness
Slide 56
Evolution by Natural Selection Natural selection occurs in any
situation in which More individuals are born that can survive
(survival of the fittest) There is natural heritable variation
(variation and adaptation) There is variable fitness among
individuals (survival of the fittest)
Slide 57
Evolution by Natural Selection Natural selection doesnt make
perfect organisms- just good enough to survive in their
environments If the environment changes, adaptations can change
also so long as its not too fast of a change
Slide 58
Common Descent As generations progress, we get species evolving
into new species descent with modification The principle of common
descent is that all living and extinct species are descended from
ancient common ancestors The tree of life