7.1,2,3: Intro To Natural Selection Flashcards
Who was Charles Darwin? Where was his most notable research done? 2)
- English naturalist
- most notable research was done at the Galapagos Islands
Charles Darwin was interested in bio geography. What is that?
The geographic distribution of species
What was Darwin’s hypothesis?
- organisms left South America and colonized the Galapagos Islands, where they diversified and gave rise to new species
What animal was Darwin most specifically interested in?
Finches
Does natural selection give organisms what they need to survive? (2)
- No
- natural selection has no knowledge of what organisms “need”
-  natural selection simply acts on genetic variations that lead to survival and reproduction
Does natural selection act for the good of a species? (3)
- no, natural selection has no intentions
- it only acts on traits that lead to survival and reproduction
- just because a trait leads to survival doesn’t mean it’s good for them

Give an example of how natural selection does not act for the good of a species.
- Let’s say we have a species of predators to have a trait that makes them the BEST predator
- overtime, they will eat all their prey, run out of a food source and starve and die
True or false: natural selection is a process involving organisms trying to adapt to their surroundings. (2)
- False
- natural selection acts on random mutations that have led to a genetic variation in the population
- organisms cannot close your eyes and cross your fingers and make a wish to adapt
True or false: in the term “survival of the fittest,” fittest means that irganisms in a population are the strongest, healthiest and fastest.
- False
- The fittest organisms simply refers to the organism that can survive and reproduce

Why doesn’t survival of the fittest refer to organisms that are the strongest, healthiest, and fastest? Use sickle cell anemia as an example. (3)
- for example, sickle cell anaemia is a trait that leads to protection against malaria.
- but individuals with sickle cell anaemia would not be classified as healthy
- sure they can survive, but they’re not strong
During his studies, Darwin proposed the idea of ____ _ ___. This is now the modern day definition of ____?
- descent with modification
- Evolution
To explain the pattern of descent with modification (evolution), Darwin propose the idea of?
Natural selection
What is the definition of natural selection?
- A process in which individuals that have certain traits tend to survive and reproduce at higher rates than other individuals because of all these traits
Natural selection acts on what?
- phenotypic variation in populations
What will some phenotypes do to an organisms fitness (ability to survive and reproduce)? (2)
- some phenotypes will increase or decrease in organism’s fitness
- measured by reproductive success
What happens to populations generally when environment’s change?
Causes selective pressures to populations
The theory of natural selection is based on two main observations that Darwin made. What are these two observations?
- traits are heritable
- more offspring are produced than can survive
Explain Darwin’s observation about how traits are heritable.
- characteristics can be passed from parent to offspring
- adaptations
What are adaptations?
- inherited characteristics of organisms that enhance their survival and reproduction
Explain Darwins observations on how more offspring are produced than can survive. (3)
- this leads to competition for limited resources, which results in differential survival
- The traits that lead to survival (“favourable” traits) will accumulate in the population
- populations evolve, not individuals
Darwin was worried about other scientists supporting his work, So he compared natural selection to artificial selection. What is artificial selection?
- the selective brreding of domesticated plants and animals to encourage the occurrence of desirable traits
What is the difference between natural selection and artificial selection? (3)
- In natural selection, nature “selects” traits that are better suited for survival and reproduction
- in artificial selection, human select traits that are desirable
- in artificial selection, domestication of plants and animals occur
Natural and artificial selection both can have what changes in their organisms, but why is natural selection different?
- both can lead to evolutionary change in the organism
- natural selection occurs in nature without the influence of humans
