Chapter 17: Speciation & Evolution Models

Question 1

Micro vs macroevolution?

Answer 1

Micro = small changes in one species. Macro = new species over time.

Question 2

Prezygotic isolation?

Answer 2

Prevents fertilization (e.g., mating behavior, timing).

Question 3

Postzygotic isolation?

Answer 3

Fertilization happens, but offspring can’t survive/reproduce.

Question 4

3 species concepts?

Answer 4

Biological, evolutionary, phylogenetic.

Question 5

2 types of speciation?

Answer 5

Allopatric (geographic), sympatric (same place).

Question 6

What is adaptive radiation?

Answer 6

One species becomes many in new environments.

Question 7

Coevolution vs convergent evolution?

Answer 7

Coevolution = two species affect each other. Convergent = different species evolve similar traits.

Question 8

Gradual vs punctuated equilibrium?

Answer 8

Gradual = slow change. Punctuated = quick bursts.

Question 9

Gene expression in speciation?

Answer 9

Small gene changes can lead to big differences.

Question 10

Is evolution goal-oriented?

Answer 10

No, it’s not.

Question 11

What is microevolution?

Answer 11

Small genetic changes within a species.

Ex: Antibiotic resistance in bacteria.

Question 12

What is macroevolution?

Answer 12

Big changes that lead to new species.

Ex: Reptiles evolving into birds.

Question 13

What is prezygotic reproductive isolation?

Answer 13

Barriers that stop mating or fertilization.

Ex: Two species mate at different times.

Question 14

What is postzygotic reproductive isolation?

Answer 14

Fertilization happens, but offspring can’t reproduce.

Ex: Mule is sterile.

Question 15

What is habitat isolation?

Answer 15

Species live in different environments.

Ex: One fish in ocean, one in freshwater.

Question 16

What is temporal isolation?

Answer 16

Mating at different times.

Ex: Daytime vs nighttime breeders.

Question 17

What is behavioral isolation?

Answer 17

Different mating behaviors.

Ex: Unique bird songs.

Question 18

What is mechanical isolation?

Answer 18

Incompatible reproductive organs.

Ex: Insects can’t physically mate.

Question 19

What is gamete isolation?

Answer 19

Sperm can’t fertilize egg.

Ex: Sea urchins releasing gametes.

Question 20

What is hybrid inviability?

Answer 20

Offspring doesn’t develop or dies.

Ex: Cross-species embryo fails.

Question 21

What is hybrid sterility?

Answer 21

Healthy hybrid, but can’t reproduce.

Ex: Mule (horse + donkey).

Question 22

What is F2 fitness?

Answer 22

Grand-offspring are weak or infertile.

Ex: Hybrid’s kids have low survival.

Question 23

What is allopatric speciation?

Answer 23

Geographic separation causes speciation.

Ex: River splits one species into two.

Question 24

What is sympatric speciation?

Answer 24

New species forms in the same area.

Ex: Polyploid plants.

Question 25

What is polyploidy?

Answer 25

Extra chromosome sets. ## Footnote Ex: Triploid bananas.

Question 26

What is autoploidy?

Answer 26

Chromosome duplication within one species. ## Footnote Ex: Self-fertilizing plants.

Question 27

What is alloploidy?

Answer 27

Chromosomes from different species. ## Footnote Ex: Hybrid plants with both parents’ DNA.

Question 28

What is the biological species concept?

Answer 28

Species can breed and make fertile offspring. ## Footnote Ex: Humans across the world.

Question 29

What is the phylogenetic species concept?

Answer 29

Based on evolutionary lineage. ## Footnote Ex: Comparing DNA to find species.

Question 30

What is the evolutionary species concept?

Answer 30

Shared traits and ancestry over time. ## Footnote Ex: Fossil evidence showing a species line.

Question 31

What is coevolution?

Answer 31

Two species evolve in response to each other. ## Footnote Ex: Bees and flowers.

Question 32

What is convergent evolution?

Answer 32

Unrelated species get similar traits. ## Footnote Ex: Sharks and dolphins both have fins.

Question 33

What are homologous structures?

Answer 33

Same structure, different function. ## Footnote Ex: Human arm and bat wing.

Question 34

What are analogous structures?

Answer 34

Same function, different structure. ## Footnote Ex: Bird wing vs insect wing.