Transcript Mutation, Evolution, and Natural Selection

K
W
What do you already
know about
evolution and natural
selection?
What do you want to
know about
evolution and natural
selection?
L
What did you learn
from our lab
“Survival of the
Beakest”?
There are 2 variations of the
beetles, green and red.
The birds prefer eating the
green beetles.
Over generations the red beetles
increase in population because
they are not eaten by the birds.
More survive to produce more
offspring.
Generations later….
Over time the red beetles have been
selected over the green beetles
So what happens to the birds now?
Natural Selection Simulation
 http://phet.colorado.edu/en/simulation/natural-selection
1) Why are there different colors?
mutation
2) Why do wolves eat white rabbit (in the equator
environment)? Brown are camouflaged
or move faster
3) Why do # brown rabbits increase over time?
Brown survive, reproduce & their babies are brown
4) What is it called when the # brown rabbits increases
over time? Evolution
5) What if the environment changed to the arctic?
The white rabbits would survive better and
the # white bunnies would increase
Why do giraffes have long necks?
Who was Charles Darwin?
•British scientist that in 1859
published The Origin of Species
•Stated that all life today came from
a common ancestor
•Change from one to many is called
evolution
•This happens by a process called
natural selection.
•
http://www.youtube.com/watch?v=
nMgLF8n4DnA
Darwin
Galapagos
Voyage of
H.M.S. Beagle,
1831 - 1836
90 feet of
ship, 74
people living
together for 5
years...
PHYSICAL: This moth
mimics an owl’s eyes
BEHAVIORAL: This monkey
is using tools to get food
CHEMICAL: this orchid
smells like a female bee
INCORRECT MODEL OF EVOLUTION:
BASED ON NEED
Why does this not work?
Change through use and disuse
Natural Selection’s Explanation
Ancestors had different
neck lengths
Through natural selection,
longer necks survived and
passed on their genes.
Eventually all giraffes
had long necks.
•225 Million Years Ago the continents were together making a
super continent called Pangaea
•The continents split and populations were separated.
•This increased the variety of living things because they were in
new environments,which would select for specific adaptations
and isolated these species from reproducing with original form.
EFFECTS OF ISOLATION
ONE Ancestor Many Varieties
• What are the different
types?
•What could cause all
the variety?
http://www.youtube.com/watch?v=sCEeefdaRcw
Common
AncestorWe did not
come from
monkeys, we
just share a
common
ancestor
Adaptation
 the evolutionary process where a
population becomes better suited to
its environment.
 This process takes many generations.
 A feature which is especially important
for an organism's survival.
 For example, the adaptation of horses' teeth
to the grinding of grass

Flat teeth (due to genetic mutation) chew grass
better
How does Evolution Work?
 Natural Selection- survival of the fittest
 Organisms best suited to their environment
 Natural selection is the result of four features of
living systems:
 1) variation – differences in the population
because of genetic mutation
 2) inheritance - parents pass on their genetic
mutations to their offspring
 3) selection - some organisms reproduce more
(fittest) than others
 4) time – happens over time, takes many
generations
Evolution
 the change in the inherited traits (passed on
from parents to offspring) of a population over
many generations.
 These traits could be:



physical (teeth shape)
chemical (ability to use sun for energy)
behavioral (run fast).
 This change is caused by mutations in the genes.
 http://www.youtube.com/watch?v=yVqJ_mQazik
Theories on Life
 Theory of Evolution
 Creationism
 Science
 Religion
 Based on evidence
 Based on faith