How Species Form

Question 1

Describe what Species is 🎀

Answer 1

• Interbreed
• Produce viable offspring
• Reproductively from other species
  (Eg. Elephants and frogs cannot interbreed)

Question 2

The formation of a new species

Answer 2

Speciation

Question 3

What are the two pathways for Speciation?

Answer 3

Transformation and Divergence

Question 4

(Pathway for Speciation) New species gradually develop as a result of mutation and adaptation to changing environmental conditions
- Old species is gradually replaced

Answer 4

Transformation

Question 5

(Pathway for Speciation) One or more species arises from a parent species.
- Adaptive radiation

Answer 5

Divergence

Question 6

Which pathway for Speciation increases biological diversity?

Answer 6

Divergence (because it increases the number of species).

Question 7

Diversification of a common ancestral species into a variety of species, all of which are differently adapted. (Ex. Galapagos Island Finches)

Answer 7

Adaptive Radiation

Question 8

For speciation to occur, two populations must be prevented from what?

Answer 8

Interbreeding

Question 9

For speciation to occur, populations must be isolated from another through a barrier. What are these 2 kinds barriers?

Answer 9

1. Geographical Barriers
2. Biological Barriers

Question 10

____________ Barriers
- Physical Separation (Ex. Mountains and Rivers)
- Prevent interbreeding because populations are physically separated.

Answer 10

Geographical

Question 11

(True/False) Isolation has to be maintained forever for speciation to occur.

Answer 11

False

Question 12

____________ Barriers
- Reproductive isolation
- When species can not produce viable offspring

Answer 12

Biological

Question 13

Biological barriers are when species can not produce viable offspring because of what?

Answer 13

1. Physical incompatibility
2. Different behaviours (bird vs frog song)
3. Different pheromones (mate attraction)

Question 14

What are the 2 models that scientists have proposed for the pace of evolution based on the fossil record?

Answer 14

Gradualism, and Punctuated Equilibrium

Question 15

Model that proposes that gradual change occurs steadily in a linear fashion.
- Big changes occur as a result of the sum of many small changes

Answer 15

Gradualism

Question 16

Model that proposes that evolutionary history consists of long periods of Equilibrium where there is little change and “punctuated” or interrupted periods of speciation.

Answer 16

Punctuated Equilibrium

Question 17

(Punctuated Equilibrium) Speciation events often follow periods of mass extinction, resulting in the next __________ being very different from the original.

Answer 17

Generation