Chapter 24 - Speciation

Question 1

Adaptive Radiation

Answer 1

rapid speciation under conditions in which there is little competition.

Question 2

Paedomorphosis

Answer 2

Retention of Juvenile Characteristics in adults.

Question 3

Population

Answer 3

considered separate species if they are reproductively isolated from each other:
they do not interbreed or they fail to produce viable, fertile offspring.
therefore, no gene flow occurs between these populations

Question 4

Prezygotic Isolation

Answer 4

individuals of different species are prevented from mating.

Question 5

Postzygotic Isolation

Answer 5

individuals from different populations do mate, but the hybrid offspring produced have low fitness and do not survive or produce offspring.

Question 6

Morphological Species Concept

Answer 6

Biologists identify evolutionarily independent lineages by differences in morphological features.

Question 7

Phylogenic Species Concept

Answer 7

Reconstructing the evolutionary history of populations. It relies heavily on DNA sequencing.

Question 8

Monophyletic group or Clade

Answer 8

On phylogenetic trees, an ancestral population plus all of its descendants

Question 9

Synapomorphy

Answer 9

a trait unique to a monophyletic group

Question 10

Ecological Species Concept

Answer 10

defines a species as a set of organisms exploiting a single set of resources, having the same range of environmental tolerances, and facing the same predators and parasites.

Question 11

Genetic Species Concept

Answer 11

Classifies populations as being of the same species if they have 97% of the same genome

Question 12

Sub-species

Answer 12

populations that live in discrete geographic areas and have their own identifying traits but are not distinct enough to be considered a separate species.

Question 13

Allopatric Speciation

Answer 13

Speciation that begins with physical isolation

Question 14

Dispersal

Answer 14

occurs when a population moves to a new habitat, colonizes it, and forms a new population.

Question 15

Vicariance

Answer 15

occurs when a physical barrier splits a widespread population into subgroups that are physically isolated from each other.

Question 16

Sympatry

Answer 16

Different populations or species that live in the same geographic region live in sympatry

Question 17

Allopolyploidy

Answer 17

Parents that belong to different species produce offspring in which chromosome number increases. In rare occasions hybridization results in fertile animal offspring.

Question 18

Niche

Answer 18

the range of ecological resources that a species can use and the range of conditions it can tolerate

Question 19

Hybrid Zone

Answer 19

A geographic area where interbreeding between two populations occurs and hybrid offspring are common.

Question 20

How does hybridization link with extinction?

Answer 20

The hybrid is favoured over one of the species. Can also lead to formation of new species

Question 21

Which concept(s) for identifying species cannot be applied to asexual or fossil species?

Answer 21

Biological Concept - cannot make deductions based on sexual reproduction

Question 22

Reinforcement

Answer 22

type of natural selection called disruptive selection, which favours extreme phenotypes over intermediate phenotypes.

Question 23

Fertilization

Answer 23

The process by which haploid gametes form a diploid zygote

Question 24

Most polyploid plants arise as a result of _____.

Answer 24

Hybridization

Question 25

How can an allopolyploid plant become a biologically fit new species?

Answer 25

If a nondisjunction event occurred that resulted in chromosome doubling, the plant’s ability to undergo meiosis would be restored and it could then produce viable gametes.