Exam 3: 7 + 7.5

Question 1

Delimitation

Answer 1

The process of finding the boundaries, or limits, of some defined entity.
= Defining a particular species

Question 2

Identification

Answer 2

Applying a species’ definition to a specimen

Question 3

Species delimitation

Answer 3

1. The process of finding the boundaries, or limits, of species
2. Identifying the limits of variation that correspond to species definitions

Question 4

Biological species

Answer 4

Individuals from populations that can (or do) interbreed in nature and have fertile offspring

Question 5

Problems with biological species

Answer 5

• Practicality: Almost impossible
• Can it be applied through time?: Hard to say…
• Can it be applied to all organisms?: Only sexually reproducing ones
• Intuitive: Yes

Question 6

Morphological species

Answer 6

Individuals from populations that can be assigned to distinct groups by discontinuous variation in form
= Individuals that look alike are the same species

Question 7

Problems with morphological species

Answer 7

• Practicality: Easy
• Can it be applied through time?: Yes
• Can it be applied to all organisms?: Yes
• Intuitive: Appears to be, but problems with cryptic species (won’t always match with the biological species concept)

Question 8

Cryptic species

Answer 8

A group of individuals that would be recognized as a separate species if we had a better capability to detect it.
= A species that truly exists but is superficially identical to another one

Question 9

Genetic species

Answer 9

Individuals from populations that share a common gene pool (or belong to a similar genetic cluster)

Question 10

Problems with genetic species

Answer 10

• Practicality: Easy w/ tech
• Can it be applied through time?: No.
• Can it be applied to all organisms?: All non-hybridizing organisms
• Intuitive: Indirectly relates to biological species concept but big grey area (morphological species concept has this problem too.) All individuals have unique alleles, and where is the cutoff?

Question 11

Ecological species concept

Answer 11

Read the paper

Question 12

Problems with ecological species concept

Answer 12

read the paper

Question 13

Phylogenetic species

Answer 13

The smallest group of individuals that share unique character states

Question 14

Problems with phylogenetic species

Answer 14

• Practicality: Difficult
• Can it be applied through time?: Yes
• Can it be applied to all organisms?: All organisms with character information and vertical transfer of genetic material (prokaryotes?)
• Intuitive: Indirectly relates to biological species concept but big grey area

Question 15

Do species exist? (Facts)

Answer 15

• Discontinuities and barriers to mating sometimes exist
• Evolution acts on alleles in populations
• Higher classifications (above species level) are DEFINITELY MAN-MADE

Question 16

Speciation

Answer 16

• The process by which new species arise
• The process by which discontinuities between lineages are created

Question 17

Why do heritable reproductive barriers emerge?

Answer 17

• They arise over time due to genetic drift and accumulation of random mutations
• They arise over time due to divergent selective pressures
• They arise due to natural selection, which favors traits that prevent hybridization

Question 18

Allopatric speciation

Answer 18

• As geographic barrier arise (vicariance event) that splits the population into two (or more sectors), populations will undergo different selective pressure and evolve differently.
• The populations remain distinct as time goes on (either morphologically, genetically, phylogenetically etc.) when their ranges meet.

Question 19

Peripatric speciation

Answer 19

Founder effect at play — a small portion of the population leaves the range and found a new range.
*NOT splitting of a population and slow drift over time

Question 20

Parapatric speciation

Answer 20

Due to differences in environmental conditions of the range, the species face different selective pressures and can evolve to have different traits under the range.
*Can lead to ring species.

Question 21

Sympatric speciation

Answer 21

Speciation that occurs within the exact same habitat
*Can occur through Fisherian selection (female choice) where the female favors different shades of males which leads to speciation.
*Also happens when the species is having divergent selection to two niches

Question 22

If hominids had head lice when moving out of Africa, what will occur in the headlice?

Answer 22

Headlice will probably undergo allopatric or parapatric speciation

Question 23

Cospeciation

Answer 23

The process of speciation occurring (roughly simultaneously) due to a strong symbiotic relationship between them