Evolution

Question 1

What is Evolution

Answer 1

Descent with modification, a change in genetics in a population from generation to generation

Question 2

Describe what is required in order for natural selection to occur.

Answer 2

-Variety of traits
-Competition (must produce more offspring than environment can support)
-Traits must be inherited (so individuals with better traits leave more offspring, Survival of the Fittest)

Question 3

Selective pressure

Question 4

Natural Selection

Answer 4

One trait is favoured over the other, so favoured traits get passed

Question 5

Survival of the Fittest

Answer 5

Result of Natural selection

Question 6

average heterozygosity

Answer 6

Average amount of alleles that are heterozygous in a whoel poplulation

Question 7

Why cant natural selection be perfect

Answer 7

1. It works with only existing variations
2. It acts for what the environment needs for the moment
   3.Adaptations are often compromises
3. Chance, Natural Selection and Environment interact.

Question 8

What is the biological species definaition?

Answer 8

(focuses on their ability to interbreed insread of physical similarities)

Question 9

What is Reproductive Isolation? What is an example

Answer 9

When barriers stop 2 different species from creating viable and fertile offspring

Question 10

There are 2 groups of frogs that are very similar living in the same lake. What might prevent them from interbreeding?

Answer 10

Temporal Isolation (diff mating seasons)
Behavioural Isolation (diff mating calls)
Gamete Isolation (diff sex organs)

Question 11

Why does a grolar bear (cross between grizzly bear and polar bear) have less fitness than its parents?

Question 12

What does Natural Selection being an Adaptive change mean?

Answer 12

It always results in making the population better suited for its environment. (unlike genetic drift and gene flow which are random and may or may not result in a better suited population)

Question 13

What is Reproductive Isolation

Answer 13

A biological barrier that stops 2 different species from MATING and producing a VIABLE, FERTILE offspring

Question 14

List prezygotic

Question 15

List post-zygotic

Answer 15

Reduced hybrid viability→ when the hybrid is born but mature into a healthy adult (wont live long)
Reduced hybrid fertility→ when hybrid is born but isn’t fertile, ex:mules
Hybrid breakdown→ when hybrid is born, and crosses with hybrids and its children aren’t fertile

Question 16

How can sexual selection cause sympatric speciation?

Question 17

What are the 3 types of Natural Selection? How do they look

Answer 17

Disruptive= the new generation puches towards the extremes
Directional= pushes towards one side
Stabilizing= creates more towards medium

Question 18

What are examples of directional, stabilizing and disruptive

Answer 18

Directional= dark moths camouflage in pollution
Disruptive= grolar bears,(not grolar bears would not survive because they’re not dark enough to camouflage in forest, BUT not light enough to camouflage in snow
Stabilizing= weight of babies

Question 19

How does Sickle Cell Anemia demonstrate Heterozygous advantage?

Answer 19

Those with 1 sickle cell recessive allele are resistant to malaria
But still wont get sickle cell anemia (because its recessive)