Natural Selection
Natural selection is the idea that organisms with different heritable traits have difference chances of _______________ & ______________.
Surviving and reproducing
Something that changes the fitness of a portion of a population and leads to new adaptations over time.
Selective pressure
A group of organisms that can interbreed and produce fertile offspring
Species
The process of humans selectively breeding plants and animals to intentionally alter their evolution and produce desirable traits (eg domesticated dogs)
Artificial selection
Fitness
The sum total of all selective pressures acting on an organism
Niche
Are lions and tigers different species? Why or why not?
Yes. Because their offspring are not reproductively viable.
My doctor told me to take an antibiotic for 7 days to clear up an infection, but I feel better after 3 days so I stop taking my medication. Why is this a bad idea?
The surviving bacteria may have survived for a reason- they are resistant. And if I stop taking my medicine the infection will return even worse than before.
The man who developed the theory of Evolution by Natural Selection and published "Origin of Species"
Summarize what the Competitive Exclusion Principle says
No two organisms can have identical niches. One will have to either adapt differently or be driven to extinction.
If two groups of snakes are separated by a mountain range that neither can slither over, what kind of reproductive isolation is this an example of? (geographical, temporal, or behavioral)
Geographical
The change in the frequency of traits in a population over time
Evolution
A genetic mutation that causes an animal's fur to become thicker is most likely to occur in which environment: A. A hot desert B. A snowy artic tundra C. A rainforest D. None of these
D. None of these. Genetic Mutations are random
Why did the rock pocket mice still have a light-colored underbelly even though the rest of their fur turned dark?
The predators were coming from above, so there was no selection for camoflauge on the belly.
Two groups of frogs stop interbreeding because one group mates in the summer months and the other mates in the winter. What type of reproductive isolation is this an example of? (geographical, temporal or behavioral)
Temporal
Human have the ability to sweat to lower our body temp. What type of selective pressure would have led to this adaptation? (competition, predation, sexual selection, or physiological stress)
Physiological stress- has to do with maintaining internal balance in the body.
A species of brown moths live on brown rocks in an environment where there are no predators eating them.
If a volcanic eruption turns the rocks black, what would we expect to find if we looked at the color of the moths after thousands of years with no environmental change?
They are still brown. No predators means to selective pressure to be camouflaged.
Male mountain goats have strong horns that they use to fight with each other.
What type of selective pressure might have led to this adaptation?
Sexual selection/ Intraspecific competition
Describe in at least 3 steps how a new species of mice might arise from a subset of an existing population.
1. Part of the population is separated by being introduced to a new island land mass.
2. Island population undergoes changes over many generations without crossbreeding with mainland mice.
3. When island mice can no longer create viable offspring with mainland mice, it is a new species.
A classmate tells you: "humans are more evolved than our ape-like ancestors because we evolved later". Explain why this is inaccurate.
Fitness is relative to environment, does not produce superior organisms later in the evolutionary timeline. (eg. chicken is not superior to t-rex)