evolution

Question 1

Darwins theory of natural selection

Answer 1

Sailed on the HMS beagle
- Natural selection: populations change over time and individuals with traits best suited to the environment will survive and reproduce.
This is called the Survival of the Fittest

Question 2

Darwin calls this Natural Selection:

Answer 2

It is important to note that Darwin did not use the word Evolution he used Descent with Modification
- Descent with Modification- theory that natural selection does not demonstrate progress but results in the ability to survive local environmental conditions

Question 3

Homologous

Answer 3

Similar internal anatomy, differnet function. (Common ancestor)
Ex. Bat wing & Human arm

Question 4

Analogous

Answer 4

Similar function, different anatomy. (No common ansestor )
Ex. Bat wing & Butterfly wing

Question 5

Vestigial structures

Answer 5

Non functioning versions of structures that were once useful and functioning to an organism’s ancestor. Ex. Goosebumps show we used to have a lot of body hair to keep warm, Tail-bone shows us, humans at some point had a tail

Question 6

Adaptation

Answer 6

Mimicry and camouflage

Question 7

Mimicry

Answer 7

Harmless species mimic harmful species, or species that predators don’t like. Ex. The Viceroy butterfly will mimic the Monarch butterfly because predators won’t eat monarchs as they don’t taste very good.

Question 8

Camouflage

Answer 8

Organisms use their appearance to blend in with their surroundings

Question 9

Fitness

Answer 9

Refers to a species ablilty to produce viable offspring in a gene pool

Question 10

Pre - zygotic:

Answer 10

Prevention of mating

Question 11

Behavioural isolation

Answer 11

behaviours that prevent other species from recognizing or selecting them for mating

Question 12

Temporal isolation

Answer 12

Two species that live in the same habitat but have different mating season

Question 13

Habitat isolation

Answer 13

Two species that live in same general area but in different habitats

Question 14

Post - zygotic

Answer 14

Prevention of fertilization

Question 15

Hybrid inviablilty

Answer 15

Death in the womb

Question 16

Hybrid breakdown

Answer 16

They can have babys, but that offspring is weak and as the generations go on, they get weaker and weaker showing consequences

Question 17

Hybrid infertilitity

Answer 17

Offspring can’t have babies

Question 18

Stabilizing Selection

Answer 18

favours an intermediate phenotype and selects against extreme variants of the phenotype - Ex weight of human babies

Question 19

Directional Selection

Answer 19

favours phenotypes at one extreme over the other - This type of selection is common during times of environmental change - Ex: colour of pepper moths or antibiotic resistant bacteria

Question 20

Disruptive Selection

Answer 20

favours extreme phenotypes rather than intermediate phenotypes - Sometimes intermediate phenotypes are completely eliminated from the population - Ex: Male coho salmon - > Very large phenotype (4500 grams or more) are better at fighting for access to females’ eggs and very small phenotype (~ 500 grams) are better at “sneaking” & fertilizing females’ eggs

Question 21

Survival of the fittest

Answer 21

organisms compete for limited resources. Organisms with favourable traits that help them survive will have an increased chance of reproduction. If they reproduce, a growing number of the population will have these traits in later generations