7.1,2,3: Intro To Natural Selection

Question 1

Who was Charles Darwin? Where was his most notable research done? 2)

Answer 1

• English naturalist

- most notable research was done at the Galapagos Islands

Question 2

Charles Darwin was interested in bio geography. What is that?

Answer 2

The geographic distribution of species

Question 3

What was Darwin’s hypothesis?

Answer 3

• organisms left South America and colonized the Galapagos Islands, where they diversified and gave rise to new species

Question 4

What animal was Darwin most specifically interested in?

Answer 4

Finches

Question 5

Does natural selection give organisms what they need to survive? (2)

Answer 5

• No
• natural selection has no knowledge of what organisms “need”
•  natural selection simply acts on genetic variations that lead to survival and reproduction

Question 6

Does natural selection act for the good of a species? (3)

Answer 6

• 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
  

Question 7

Give an example of how natural selection does not act for the good of a species.

Answer 7

• 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

Question 8

True or false: natural selection is a process involving organisms trying to adapt to their surroundings. (2)

Answer 8

• 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

Question 9

True or false: in the term “survival of the fittest,” fittest means that irganisms in a population are the strongest, healthiest and fastest.

Answer 9

• False
• The fittest organisms simply refers to the organism that can survive and reproduce
  

Question 10

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)

Answer 10

• 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

Question 11

During his studies, Darwin proposed the idea of ____ _ ___. This is now the modern day definition of ____?

Answer 11

• descent with modification

- Evolution

Question 12

To explain the pattern of descent with modification (evolution), Darwin propose the idea of?

Answer 12

Natural selection

Question 13

What is the definition of natural selection?

Answer 13

• 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

Question 14

Natural selection acts on what?

Answer 14

• phenotypic variation in populations

Question 15

What will some phenotypes do to an organisms fitness (ability to survive and reproduce)? (2)

Answer 15

• some phenotypes will increase or decrease in organism’s fitness
• measured by reproductive success

Question 16

What happens to populations generally when environment’s change?

Answer 16

Causes selective pressures to populations

Question 17

The theory of natural selection is based on two main observations that Darwin made. What are these two observations?

Answer 17

• traits are heritable

- more offspring are produced than can survive

Question 18

Explain Darwin’s observation about how traits are heritable.

Answer 18

• characteristics can be passed from parent to offspring

- adaptations

Question 19

What are adaptations?

Answer 19

• inherited characteristics of organisms that enhance their survival and reproduction

Question 20

Explain Darwins observations on how more offspring are produced than can survive. (3)

Answer 20

• 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

Question 21

Darwin was worried about other scientists supporting his work, So he compared natural selection to artificial selection. What is artificial selection?

Answer 21

• the selective brreding of domesticated plants and animals to encourage the occurrence of desirable traits

Question 22

What is the difference between natural selection and artificial selection? (3)

Answer 22

• 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

Question 23

Natural and artificial selection both can have what changes in their organisms, but why is natural selection different?

Answer 23

• both can lead to evolutionary change in the organism

- natural selection occurs in nature without the influence of humans