Transcript Change Over Time

Change Over Time
Warm Up Question

The cockroach originated on Earth more
than 250 million years ago and is still thriving
all over the world today. Species of
dinosaurs evolved around the same time
period and went extinct 65 million years
ago.
Warm Up Question
 Why
has this tiny
species been so
successful for so
long, and other
species die out
in a relatively
short time?
I. Adaptations:

Adaptation Anything that makes a species
better suited to its environment.
A.
Types:
1. Structural Adaptations
2. Physiological Adaptations
3. Behavior Adaptations
Adaptation Video Clip



What adaptation(s) does
the mantis possess that
helps it survive in it’s
environment?
How did this mantis
populations evolve to
possess this adaptation?
What pressure would the
mantis population face if
their environment
changed?
PBS: Evolution Adaptation Clip
1. Structural Adaptation Changes in the
structure of a body part.

Examples Camouflage
Mimicry
2. Physiological Adaptation
Changes to an organism’s metabolic
processes.
Ex. -Antibiotic resistant bacteria
-Insects that are resistant to pesticides
3. Behavioral Adaptation
Help an organism find food, protect itself, or
reproduce.
II. Evolution of Species

Species a group of organisms that are
closely related and can mate to produce
fertile offspring.
A. Evolution: Is the process by which
species change in over time.
1. Species evolve
from pre-existing
species.
2. Successful organisms survive and pass
on their genes, others go extinct.
Populations can
change
(evolve),
individuals can
not!!!
III. Evidence of Evolution:
A. Fossils

Scientist study fossils to find evolutionary clues.

Fossils show how populations of organisms
changed over a long period of time.
Whale Evolution Website
Whale Evolution Video Clip
Transitional Fossils

Fossils or
organisms that
show the
intermediate states
between an
ancestral form and
that of its
descendants
Transitional Fossil
Transitional Fossils

Fossils or
organisms that
show the
intermediate states
between an
ancestral form and
that of its
descendants
IV. Anatomy

Understanding homology and analogy
A. Homologous Structures

Modified body parts that have similar
structure and function in different organisms.
*Share a common ancestry. Can be used to
show evolution.
B. Analogous Structures

Similar function, but different structure.

Two characters are analogous if the two
lineages evolved independently.
C. Vestigial Structures

Any body structure that is reduced
in function in a living organism, but
may have been used in an
ancestor.
Examples
-Appendix in humans
-Hips on whales
V. DNA (Molecular Biology)
Closely related
species have similar
DNA patterns that
code for proteins.
 Ex: Human DNA is
20% identical to a
mouse, and 98%
identical to a
chimpanzee.

A. Changes in Genes
1. Mutation a change
in the nucleotidebase sequence of a
gene or DNA
molecule.

A Mutation Story Video
Ex: Sickle Cell
Anemia