Transcript CH 11 Notes - Haiku Learning

Chapter 11: Evolution:
Evidence and Theory
Essential Question: Why is there a
large variety of living things? How
did the differences come about?
I. History of Evolutionary Thought
A. The Idea of Evolution
1. Evolution
a) Development of new types of organisms from
preexisting types of organisms over time
(difference between ancestor and relative: science
does not propose that humans evolved from
chimpanzees: humans and chimpanzees share a
common ancestor)
b) Heritable change in the characteristics within a
population from one generation to the next
Evolution
Fun Facts about Darwin:
(do not need to write down)
 Born 1809 to a wealthy family – his father
was a physician and wanted him to be a
doctor or a minister.
 Enrolled at the University of Edinburgh at the
age of 16, but was repelled by surgery with
no anesthesia – very experimental at the time.
He skipped lectures to collect biological
specimens instead.
 His father sent him to the University of
Cambridge to study theology in 1827, but
had little interest in the course of study.
Discovered his love of natural history.
 While at Cambridge he became close friends
with John Henslow (botanist).
2. Charles Darwin: naturalists that took a trip around the
world in the 1830’s and observed diverse and
unique organisms
a) Galapagos Islands: noticed that
groups of animals varied from island
to island (finches and tortoises)
b) Noticed similarities and differences among
animals around the world
c) Darwin took years to put together his evidence
for a theory of evolution and his theory forms the
basis for modern thoughts on evolution
The Voyage of the Beagle
• 5-year mapping and collecting
expedition to South America
and the South Pacific
• Darwin’s role as the
naturalist: collect specimens
(including fossils), observe
thousands of species, record
observations – take notes and
make sketches
• Dropped off at different ports
along the journey and would be
picked up months later
(seasick)
Giant Tortoises of the
Galápagos Islands
Section 15-1
Pinta
Pinta Island
Tower
Marchena
Intermediate shell
Fernandina
James
Santa Cruz
Isabela
Santa Fe
Hood Island
Floreana
Isabela Island
Dome-shaped shell
Hood
Saddle-backed shell
Galapagos’s Tortoise
• Galapagos's tortoise can
live for over 150 years
• Eat plants
• Different shells
depending on the island
Galapagos's Tortoise
3. Ideas of Darwin’s time
a) Most scientist thought that all species were
permanent and unchanging
b) Thought that the Earth was only thousands years
old and not billions
c) Scientists began to present evidence that the
species on Earth have changed over time and that the
Earth was much older
4. Ideas about geology
a) Strata: rock layers; were being studied and strata are
formed as new layers of rock are deposited over time
b) Lower strata were formed first
and are the oldest
c) Different layers of strata hold fossils of different
kinds of organisms
d) Showed that organisms in the past differed greatly
from any living species
e) Some species become extinct: species ceased to
live after a point in time
f) Geologic processes that have changed the shape of
Earth’s surface in the past continue to work in the
same ways (uniformitarianism)
g) Darwin used the idea that if the Earth could
change, organisms could also change
5. Lamarck’s ideas on Evolution: supported the idea
that populations of organisms change over time
a) Acquired trait: organisms could acquire traits
during their lifetimes as a result of experience or
behavior and then pass on those traits to offspring
b) Acquired traits was not correct
Lamarck
Section 15-2
Lamarck’s Theory of
Evolution
B. Darwin’s ideas
1. Darwin’s travels around the world help him form a theory
to explain evolution and he published a book called On the
Origin of Species by means of Natural Selection
2. Descent with Modification: used to describe the process
of evolution
a) Every species must have descended by reproduction from
preexisting species
b) Species must be able to change over time
c) All species have descended from only one or a few
original kinds of life
3. Galapagos island finches: 13 different species of
finches that came from just a few original species of
finches
a) Each island had a different type of food source
b) The beaks of the finches of each island adapted
to the certain kind of food
Darwin
C. Natural selection: process by which individuals that
are better adapted to their environment survive and
reproduce more successfully than less well adapted
individuals natural selection
Four main parts of Darwin’s
reasoning for natural selection
1. Overproduction: more offspring can be
produced than can survive to maturity
a) Environment limits the population of all
organisms by causing deaths or by limiting births
2. Genetic variation: within a population,
individuals have different traits and the
traits can be inherited
3. Struggle to survive: individuals must compete to
find food, shelter, etc.
a) Some variations improve an individual’s chance
to survive and reproduce, but some variations
reduce the chance
b) Adaptation: trait that makes an individual
successful in its environment Adaptation
4. Differential reproduction: organisms with the best
adaptations are most likely to survive and reproduce
a) The organism will pass on its traits through
inheritance to its offspring and the trait will become
more frequent in the population
b) Theory of natural selection proposes that nature
changes species by selecting traits. The
environment “selects” the traits that may increase in
a population by selecting the parents for each new
generation
c) “Survival of the fittest”
d) Fitness: organisms ability to reproduce and pass
on its traits Fitness
II. Evidence of evolution: gradual modifications are
seen
A. Fossil record
1. Fossil: remains or traces
of an organism that died long ago
a) Shows that different types of organisms appeared
at different times and places on Earth
b) Extinct: species is no longer alive
c) Most powerful evidence of evolution
• Rock layers
2. Transitional species: species have features that
are intermediate between those of ancestors and
later descendant species
B. Biogeography: study of the location of organisms
around the world
1. Animals around the world seemed closely related
yet were adapted to different environments
2. Mammals of Australia resemble wolves, cats and
mice, but are marsupials, so they probably evolved
in isolation
C. Anatomy and Embryology
1. Anatomy: study of the body structure of organisms
2. Embryology: study of how organisms develop
3. Homologous structures: structures that
occur in different species and that originated
by heredity from a structure in the most
recent common ancestor
a) Related structure but function may be
different
b) Example: limb bones of humans,
penguins, alligators and bats Homologous
4. Analogous structures: closely related functions but
do not come from the same ancestor
a) Example: wings on birds, bats, and moths have
different structures that evolved independently
Analogous
5. Vestigial structures: no function in the organisms,
but they resemble structures that had a function in
related organism
a) Appendix and tailbone in humans
Vestigial
Pelvic bones in whales.
in snakes.
.
Ex – eyes on cave dwelling animals, wings on flightless birds
Blind Cave Salamander
D. Biological Molecules
1. Compare DNA, RNA, and proteins of
organisms
2. Greater the number of similarities between
any given species, the more closely the species
are related through a common ancestor
E. Phylogeny: relationships by ancestry among groups
of organism
1. Tree is made using different evidence to show how
closely organism are related
2. Trunk: represents a past species that could have
been the ancestor of all these animals
3. Branches: separate population
4. More closely related groups appear closer to each
other on a branch Phylogeny
III. Evolution in Action: evolution is a continuous
process and it is going on today
A. Convergent evolution: process by which different
species evolve similar traits even though they had
different ancestor
1. Example: Sharks and dolphins have similar body
shapes but one is a fish and one is a mammal
B. Divergent evolution: descendants of a single
ancestor become more and more different due
to different environments: produced the large
variety of species alive today
1. Example: Galapagos’s Island finches
Comparison
C. Artificial selection: human breeder chooses
individuals that will parent the next generation
1. Dogs and other domesticated animals
2. Plants like corn and oats
D. Coevolution: two or more species have evolved
adaptations to each other
1. Predators and prey
2. Parasites and hosts
3. Plant eating animals and the plant
4. Humans have developed and used antibiotics to kill
bacteria, but some bacteria have evolved to resist the
antibiotics
coevolution
• Darwin
• Prezi