EVOLUTION, what is it?
- organisms change over time.
How do organisms evolve?
- in order for the organism to evolve, it must first survive.
- Extinct organisms do NOT evolve.
How is evolution explained?- Scientists use fossils as evidence to explain evolution.
- Fossils are evidence of past life. Example below:
What was the first organism to inhabit this planet?
- The first organism to inhabit this planet was bacteria. Example below:
According to Darwin... (His explanation of natural selection)
1. In nature, organisms produce more offspring than will survive.
2. In any population, there is always variations among species
3. Individuals with favorable variations or traits survive the environment, passing on those variations or traits to the next generation
4. Overtime, offspring with certain variations make up most of the population and may look entirely different from their ancestors.
What are the mechanisms that drive evolution?
- In order to evolve, the organism must live or be selected.
- The environment is the selecting agent
- The mechanisms that drive evolution are mutations and genetic recombination through sexual reproduction
Problem
Use Darwin's theory of natural selection to explain why some bacteria that was once susceptible to certain antibiotics are becoming resistant.
Answer:
-Populations of bacteria produced more offspring than will survive
-In any given population of bacteria there is variation, like resistance to antibiotics.
-Bacteria with favorable traits, like resistance to antibiotics survive, reproduce and pass on the traits.
-Overtime, resistant bacteria make make up most of the population because they are the ones that survived.
How does over-crowdedness lead to natural selection?
- Over-crowdedness leads to competition. During competition, organisms that have favorable traits survive, reproduce and pass on those traits.
What are traits?
- Traits are your characteristics.
- Ex, skin color, eye color and height.
VOCAB:
Camouflage is when the organism blends in with the environment. This trait helps the organism survive by allowing the organism to escape predators or become less visible to its preys.
Adaptive traits are any structural or physiological or behavioral characteristics that help the organism survive the environment.
