Download What is Evolution? How has evolution lead to the diversity of life?

Adaption, Fitness, and Evolution
Essential Question: How has
evolution lead to the diversity of
life?
Important terms
• Adaption: Any trait that helps an organism survive
and reproduce in its environment
• Fitness: The ability to SURVIVE and REPRODUCE
So an organism is FIT (has a high fitness) if it can
survive and reproduce. – SURVIVAL OF THE FITTEST
Let’s look at some examples…………
Adaptions
How many can you find?
Adaptions – What about teeth, eyes,
speed?
Adaptions
How many can you find?
• Large eyes for
low light
• Flexible neck
for following
prey
• Sharp talons for
catching prey
• Silent flight
How have alligator’s adapted to their
environment?
One more example…
What causes theses changes - MUTATIONS!
• Changes in the structure of
the DNA
• Adds genetic diversity to the
population
• May or may not be adaptive
(benefical)
– Depends on the
environment! Remember
the “most FIT” will survive
and pass on their traits
Sooooo….What’s Evolution?
• The change in a POPULATION’S genetic makeup (gene
pool) over time (successive generations)
– Those with selective advantages (i.e., adaptations),
survive and reproduce
– All species descended from earlier ancestor species
– Sometimes results in new species
Natural Selection drives evolution - it is a process by
which forms of life having traits that better enable
them to adapt to specific environmental pressures, as
predators, changes in climate
The Case of the Peppered Moths
• Industrial revolution
– Pollution darkened tree
trunks
• Camouflage of moths
increases survival from
predators
• Directional selection
caused a shift away from
light-gray towards darkgray moths
Darwin’s Finches
Fossils