1. Evolution and Natural Selection
SURVIVAL OF THE FITTEST

2. Charles Darwin and Natural Selection
Charles Darwin is best known for his contributions to the theory of Evolution
On a five year voyage on a ship called the Beagle, Darwin recorded his observations of organisms and fossils he found along the way
This led Darwin to develop the idea of evolution and natural selection

3. Survival of the Fittest
“Survival of the Fittest” means that those organisms best adapted to their environment will survive, reproduce, and pass on genes
“Fittest” means best adapted, not strongest!

4. What is an Adaptation?
Any heritable trait an organism has that helps it to survive
What are some adaptations of this falcon?

5. Abut Adaptations
If an organism does not have adaptations to best fit its environment, it will die
“Survival of the Fittest”
Example: Bird beaks-Imagine that birds had different sized beaks in an area where the food source was seeds. In order to crack them, the birds needed a large, strong beak. Which would survive and reproduce?

6. Natural Selection
Species have the potential to increase exponentially, but environmental factors maintain lower population numbers
Resources required to sustain life
Environmental conditions
Relationships among organisms in food web
Changing environments select for specific phenotypes
Those organisms with favorable adaptations survive, reproduce, and pass on their alleles to future generation
Over time, the accumulation of favored alleles leads to a change in species (change over time = evolution)

7. Case Study: Antibiotic Resistant Bacteria
Organisms are constantly changing and adapting; bacteria reproduce and evolve quickly to adapt to constant changes!
Humans often use antibiotics to combat harmful bacteria (ex. Staphylococcus)
Some bacteria are born with a natural resistance (an adaptation!) to the antibiotic
These bacteria will survive and reproduce, creating a group that are resistant to the drugs