Topic 5

Question 1

What are the modes of evolution?

Answer 1

Microevolution and macroevolution

Question 2

What is microevolution?

Answer 2

Evolution at the population level, is usually caused by selection or drift

Question 3

What is macroevolution?

Answer 3

Evolutional change above species level. It is the origin of complex novel characters, the appearance of higher taxa, mass extinctions and speciation

Question 4

What is the biological species concept?

Answer 4

Consists of a group of actually or potentially interbreeding individuals that are reproductivly isolated from other such groups

Question 5

What are some problems with the biological species concept?

Answer 5

It only applies to sexually reproducing species, suggest that two different species would never mate and produce offspring, some species are more unique then the rest, at extremes of disrupting “species” differ

Question 6

What is reproductive isolation? What are the 2 types?

Answer 6

Maintaining species differences. Pre-zygotic isolations and postzygotic isolations

Question 7

What is prezygotic isolation? What are its mechanisms?

Answer 7

This prevents 2 individuals from creating a zygote. Ecological, Temporal, Behavioral, Mechanical and Gamete

Question 8

What is ecological isolation?

Answer 8

Habitat selection is different, tree canopy vs ground

Question 9

What is temporal isolation?

Answer 9

Species reproduce during different times, different seasons and different time of day

Question 10

What is behavioral isolation?

Answer 10

Courtship patterns, pheromones and others differ between species

Question 11

What is Mechanical isolation?

Answer 11

The organisms are anatomically incompatible

Question 12

What is Gamete isolation?

Answer 12

The sperm and egg cannot fuse

Question 13

What is Postzygotic isolation? What are its mechanisms?

Answer 13

After a zygote is produced there is a reason it is not a species. Mechanisms include: zygote death, hybrid infertilely and hybrid inviability

Question 14

What is speciation?

Answer 14

The formation of a new and distinct species in the course of evolution

Question 15

What is cladogenesis?

Answer 15

The branching or splitting of a lineage

Question 16

What is anageneis?

Answer 16

Evolutionary change within a lineage, resulting in differences in sister lineages

Question 17

What is allopatric speciation?

Answer 17

The first step toward reproductive isolation happens when a single population becomes subdivided by a geographical barrier

Question 18

What is sympatric speciation?

Answer 18

Subgroups can from within a continuous habitat. If individuals in the subgroup stop mating with individuals of the larger population they may eventually become a new species

Question 19

What is a hybrid?

Answer 19

An individual formed by mating between unlike forms, usually genitically differentiated populations or species

Question 20

What is reinforcement?

Answer 20

2 species create a hybrid that is not viable for some reason. This reinforces the idea that they should remains 2 species

Question 21

What is fusion?

Answer 21

Reproductive barriers weaken until 2 species become 1

Question 22

What is stability?

Answer 22

Fit hybrids continue to be reproduced along side each individual species

Question 23

What is punctuated equilibrium?

Answer 23

Speciation happens rapidly, followed by relatively long periods of stasis (no change)