Turn in Warm-ups from 1/29- 2/6 (Pass towards middle)
Warm-up 2/12:
•What is Struggle to Survive?
•Give an Example.
•Why is struggle to survive key to Natural Selection?
•Give two examples of Evidence that scientist have to
support evolution. (You should have learned some in
middle school)
Evolution defined…
 Evolution is a process of
gradual modifications
 Darwin called this descent with
modification
 Many animals and plants shared common ancestors
and deviated from that common ancestor overtime
Organism 1
Ancestor
Organism 2
Fossils

Fossils provide geologic
evidence of evolution

Fossils in older layers are
more primitive than those
in the upper layers
Transitional Species:
- Descent with modification states that newer
species are modified versions of older
species
- Fossil record contains the intermediates
Anatomy
 Vestigial organs - a group of organs with no
particular use now but may have been useful in
ancestors (tailbone coccyx or hip bones in whales)
Anatomy cont.
 Homologous Structures: body
parts that are similar in
structure may have different
functions
 Indicating at some point way in
the past they did the same job
and came from a common
ancestor
Anatomy cont.
 Analogous Structures:
same functions but
different development
 ex. a butterfly wing and a
bat wing
 Indicates that
populations evolved to
be better suited to the
environment
Warm-up 2/13
 What is the difference between Homologous and
Analogous Structures?
 Name 3 ways that the fossil record gives evidence for
evolution.
Evidence for Evolution Part b
(continuation of Tuesdays notes)
Biogeography
 Certain animals in one location share similar traits
(I.E. marsupials in Australia)
Embryology
 Similar likenesses in
embryos of organisms is
evidence of descent with
modification
Biological Molecules
DNA  RNA Proteins
 Similar proteins means similar DNA
 The longer it’s been since they shared a common
ancestor the more differences in protein
Chapter 15-3
pp. 308-311
Evolution defined…

 Evolution of a population is due to environment and
the interaction of other species
 Evolution acts on phenotype, not genotype
Artificial Selection

 Humans breed for specific traits causing differences
in species (i.e. dog breeding)
Examples of Evolution
 Convergent evolution:

Organisms with very
different ancestors become
more alike due to a common
environment
 Ex. fish and whalescompare analogous
structures
 Divergent evolution: populations become more and
more dissimilar to adapt to the environment-compare
homologous structures

 Appearance of birds with different sized beaks that are
specific for size of bird seed
Adaptive radiation


Population undergoes divergent evolution until it
fills all areas of the environment
 Co-evolution: as one species evolves another does
(parasites and hosts)
