Summary of Darwin’s Theory
1. Organisms differ; variation is inherited
2. Organisms produce more offspring than survive
3. Organisms compete for resources
4. Organisms with advantages survive to pass those
advantages to their children
5. Species alive today are descended with
modifications from common ancestors
Natural Selection
The traits that help an organism survive in a particular
environment are “selected” by the conditions of the
environment
Natural
Selection
The environment
determines which
traits are favorable
for survival.
It follows Logically that …
• Some individuals will be better suited to their
environment - they will survive and reproduce
more successfully than individuals without those
characteristics.
• Future generations will thus contain more genes
from better-suited individuals.
• As a result, characteristics will evolve over time to
resemble those of the better-suited ancestors.
Regents Review Question # 1
Ancestors of the giant panda had rounded paws with
five very short toes. Today, the giant panda has a sixth
toe, often referred to as a thumb, even though it
develops from a wrist bone. This unique thumb is an
adaptation that allows the panda to easily hold and eat
bamboo shoots. The presence of the giant panda’s
thumb is most likely the result of
(1) natural selection
(2) selective breeding
(3) asexual reproduction
(4) ecological succession
Regents Review Question # 1 (answer)
Ancestors of the giant panda had rounded paws with
five very short toes. Today, the giant panda has a sixth
toe, often referred to as a thumb, even though it
develops from a wrist bone. This unique thumb is an
adaptation that allows the panda to easily hold and eat
bamboo shoots. The presence of the giant panda’s
thumb is most likely the result of
(1) natural selection
(2) selective breeding
(3) asexual reproduction
(4) ecological succession
Regents Review Question # 2
A species that lacks the variation necessary to adapt to
a changing environment is more likely to
(1) develop many mutated cells
(2) become extinct over time
(3) begin to reproduce sexually
(4) develop resistance to diseases
Regents Review Question # 2 (Answer)
A species that lacks the variation necessary to adapt to
a changing environment is more likely to
(1) develop many mutated cells
(2) become extinct over time
(3) begin to reproduce sexually
(4) develop resistance to diseases
Regents Review Question #3
Which statement is best supported by the theory of
evolution?
(1) Genetic alterations occur every time cell
reproduction occurs.
(2) The fossil record provides samples of every
organism that ever lived.
(3) Populations that have advantageous
characteristics will increase in number.
(4) Few organisms survive when the environment
remains the same
Regents Review Question #3 (Answer)
Which statement is best supported by the theory of evolution?
(1) Genetic alterations occur every time cell reproduction occurs.
(2) The fossil record provides samples of every organism that ever
lived.
(3) Populations that have advantageous characteristics will
increase in number.
(4) Few organisms survive when the environment remains the
same.
Regents Review Question # 4
The diagram below represents the bones of the forelimbs of two animals alive
today that most likely evolved from a common ancestor. Members of the original
ancestral population were isolated into two groups by natural events. If these two
animals did have a common ancestor, which statement would best explain why
there are differences in the bones?
(1) Changes occurred to help the animals return to their original environment.
(2) Changes contributed to the survival of the organisms in their new
environment.
(3) Changes helped reduce competition within each group.
(4) Changes indicate the species are evolving to be more like the ancestral
species.
Regents Review Question # 5
The kit fox and red fox species are closely related. The kit fox lives in the desert,
while the red fox inhabits forests. Ear size and fur color are two differences that
can be observed between the species. An illustration of these two species is
shown below.
Which statement best explains how the differences between these two species
came about?
(1) Different adaptations developed because the kit fox preferred hotter
environments than the red fox.
(2) As the foxes adapted to different environments, differences in appearance
evolved.
(3) The foxes evolved differently to prevent overpopulation of the forest habitat.
(4) The foxes evolved differently because their ancestors were trying to avoid
competition.
Natural
Selection
explains the
development
of pesticide
resistance in
insects
Natural Selection is also responsible for:
Antibiotic resistance in bacteria
MRSA methicillin-resistant
Staphylococcus aureus bacteria
Necrotizing Fasciitis
Streptococcus pyogenes aka “Flesh Eating Bacteria”
Classification
Classification the grouping of
information or objects based on
similarities.
Naming Organisms
•We only know about a fraction of the organisms
that exist or have existed on Earth.
• A unique scientific name is given to
each species whether it’s alive today or extinct.
• The scientific name comes from one of two
“dead” languages – Latin or ancient Greek.
Binomial Nomenclature
a two name system for writing scientific names.
•The genus name is written first (always Capitalized).
•The species name is written second (never capitalized)
Felis catus
Felis c
Equus
burchelli
The Dichotomous Key
• A key is a device for easily and quickly
identifying an unknown organism.
• The dichotomous key is the most widely used
type in biological sciences.
• The user is presented with a sequence of
choices between two statements, couplets,
based on characteristics of the organism. By
always making the correct choice, the name of
the organism will be revealed.
Here's an example in written form using these items:
1. a. Organism is living........................................................go to 4.
1. b. Organism is nonliving..................................................go to 2.
2. a. Object is metallic........................................................go to 3.
2. b. Object is nonmetallic..................................................ROCK
3. a. Object has wheels......................................................BICYCLE.
3. b. Object does not have wheels......................................TIN CAN.
Regents Review Question #
ANSWER:
Alopias vulpinas
A phylogenetic tree or
evolutionary tree is a
branching diagram or "tree"
showing the evolutionary
relationships among various
biological species based upon
similarities and differences in
their physical and/or genetic
characteristics.
It also is called a cladogram.
Phylogenetic
Tree
Regents Review Question # 6
Which statement concerning the evolution of species A, B, C, D,
and E is supported by the diagram below?
(1) Species B and C can be found in today’s environments.
(2) Species A and D evolved from E.
(3) Species A and C can still interbreed.
(4) Species A, B, and E all evolved from a common ancestor and
all are successful today.
Regents Review Question # 6
Which statement concerning the evolution of species A, B, C, D,
and E is supported by the diagram below?
(1) Species B and C can be found in today’s environments.
(2) Species A and D evolved from E.
(3) Species A and C can still interbreed.
(4) Species A, B, and E all evolved from a common ancestor and
all are successful today.
Regents Review Question # 7
An evolutionary pathway is represented below.
Which statement about evolutionary pathways is most accurate?
(1) All evolutionary pathways show that life began with autotrophic
organisms that soon evolved into heterotrophic organisms.
(2) Two organisms on the same branch of an evolutionary pathway are
more closely related to each other than to those on distant branches.
(3) All the organisms shown at the ends of evolutionary pathway branch
tips are alive today.
(4) Evolutionary pathways show that evolution is a short-term process.
Regents Review Question # (Answer)
An evolutionary pathway is represented below.
Which statement about evolutionary pathways is most accurate?
(1) All evolutionary pathways show that life began with autotrophic
organisms that soon evolved into heterotrophic organisms.
(2) Two organisms on the same branch of an evolutionary pathway
are more closely related to each other than to those on distant
branches.
(3) All the organisms shown at the ends of evolutionary pathway branch
tips are alive today.
(4) Evolutionary pathways show that evolution is a short-term process.
Regents Review
Question # 8
An inference that can be made from information in the diagram is that
(1) many of the descendants of organism B became extinct
(2) organism B was probably much larger than any of the other organisms
represented
(3) most of the descendants of organism B successfully adapted to their environment
and have survived to the present time
(4) the letters above organism B represent members of a single large population with
much biodiversity
Regents Review
Question # 8
An inference that can be made from information in the diagram is that
(1) many of the descendants of organism B became extinct
(2) organism B was probably much larger than any of the other organisms
represented
(3) most of the descendants of organism B successfully adapted to their environment
and have survived to the present time
(4) the letters above organism B represent members of a single large population with
much biodiversity