Species and Speciation

Question 1

How does new species evolve?

Answer 1

Through Speciation
- The process by which new species form
- ASEXUAL split two or more diff species
- SEXUAL evolution to point where members can no longer breed with members of another population that did not evolve

Question 2

What is a Species?

Answer 2

Biological Species Concept
- Group of Population that Evolves Independently (alleles don’t move between gene pools of diff species)
- Groups of Actually or Potentially Interbreeding Natural Populations (reproductively isolated from each other)

Question 3

What biologist coined the correct “biological species” concept?

Answer 3

Ernst Mayr

Question 4

What are the Two Phases on How Speciation Happens?

Answer 4

• Geographic Isolation
• Reproductive Isolation

Question 5

When does speciation occur?

Answer 5

When Sexually reproducing members of a population can no longer produce fertile offspring with each other (prevent flow of genes between two or more populations)

Question 6

How does Geographic Isolation occurs?

Answer 6

When different groups of the same population of a species become physically isolated from one another for a long period of time

Question 7

How does Reproductive Isolation occurs?

Answer 7

Mutation and Change by Natural Selection operate independently in the gene pools of geographically isolated populations

Question 8

Mechanisms for the Origin of Species

Answer 8

• Allopatric Speciation (geographic isolation)
• Sympatric Speciation (reproductive isolation)

Question 9

What’s Allopatric Speciation?

Answer 9

• two populations are geographically separated from one another
• no gene flow eventually will accumulate genetic differences

Question 10

What’s Sympatric Speciation?

Answer 10

• two populations share the same geographical area

Question 11

What are the factors that can lead to sympatric speciation?

Answer 11

• Ecological Isolation of a Population (within the same geographic area but different habitats)
• Changes in Chromosomes Number (i.e plants polyploidy multiple copies of each chromosomes)

Question 12

What are the Mechanisms of Reproductive Isolation?

Answer 12

• Premating/Prezygotic Isolating Mechanisms (prevent mating between species)
• Postmating/Postzygotic Isolating Mechanisms (prevent the formation of vigorous, fertile hybrids between species)

Question 13

Prezygotic Isolating Mechanisms

Answer 13

• GEOGRAPHICAL Isolation (physical barrier separation)
• ECOLOGICAL Isolation (diff habitats/areas)
• TEMPORAL Isolation (breed on diff times)
• BEHAVIORAL Isolation (diff courtship and mating rituals)
• MECHANICAL Incompatibility (reproductive structures incompatibility)

Question 14

Postzygotic Isolating Mechanisms

Answer 14

• GAMETIC INCOMPATIBILITY (no fertilization of egg of diff sperm from diff population)
• HYBRID INVIABILITY (offspring fail to survive to maturity)
• HYBRID INFERTILITY (offspring sterile or have reduced fertility)

Question 15

What’s the common reason for hybrid infertility?

Answer 15

failure of chromosomes to pair properly during meiosis (eggs and sperm never develop)

Question 16

What’s another process that affects the number and types of species aside from Speciation?

Answer 16

Extinction
- Biological Extinction (entire species cease to exist)
- Local Extinction (population of species extinct over a large region (not entirelyyy))

Question 17

What happens to a population of a species when environmental conditions change?

Answer 17

• Adapt through natural selection
• Migrate
• Extinction

Question 18

What’s Species Diversity? What’s its Importance?

Answer 18

• number of different species
• Major component of Biodiversity
• Increase the Sustainability of some Ecosystems

Question 19

What are the examples of Generalist Species?

Answer 19

Flies, Cockroaches, Mice, Rats, White-tailed deer, Raccoons, and Humans

Question 20

What are the examples of Specialist Species?

Answer 20

Panda, Koala, Tarsier

Question 21

What are Generalist Species?

Answer 21

• Live in many diff places
• Tolerate Wide range of Environmental Conditions
• Eat variety of Foods

Question 22

What are Specialist Species?

Answer 22

• Live only one type of habitat
• Use one or a few types of food
• Tolerate narrow range of climatic and environmental conditions

Question 23

What are the Classifications of Niches?

Answer 23

• Native Species
• Nonnative Species
• Indicator Species
• Keystone Species
• Foundation Species

Question 24

What are Native Species?

Answer 24

normally live and thrive in a particular ecosystem

Question 25

What are Nonnative Species?

Answer 25

migrate into or deliberately accidentally introduced into an ecosystem
A.K.A ALIEN, Invasive, Exotic Specie

Question 26

What are Indicator Species?

Answer 26

Provide early warnings of damage to a community or an ecosystem
I.E:
- trout species
- birds
- butterflies
- Frogs
- Caged Canaries

Question 27

What are Keystone Species?

Answer 27

• Roles have a large effect on types and abundances of other species in an ecosystem
• Usually Predators
  I.E:
• pollination process species (bees, butterflies, hummingbirds, bats…)
• alligator, wolf, leopard, lion, some shark species,
• sea otter (kelp)

Question 28

What are Foundation Species?

Answer 28

Shapes communities by creating and enhancing their habitats in ways that benefit other species
I.E:
- Elephants
- Beavers (ecological engineers)