Speciation + Evolution

Question 1

Define Speciation:

Answer 1

The process of forming a new species

Question 2

Define Microevolution:

Answer 2

Small-scale evolutionary changes within a population over a single lineage, can lead to genetic variation but doesn’t result in a new species

Question 3

Define Macroevolution:

Answer 3

Larger scale evolutionary changes in the genetic frequency that. produces a lineage split, producing 2 or more distinct species.

Question 4

Requirements for a new species?

Answer 4

They must be reproductively isolated from its original species, it cannot produce fertile offspring with its original species

Question 5

Define RIM:

Answer 5

Reproductively isolating mechanisms which are any barriers that prevent interbreeding

Question 6

Define Prezygotic RIMs:

Answer 6

RIMs that occur prior to an egg being fertilised / before the zygote is formed

Question 7

Define Postzygotic RIMs:

Answer 7

RIMs that occur after the egg has been fertilised and a zygote is formed

Question 8

Define Species:

Answer 8

A group of individuals that are able to successfully interbreed under natural conditions and produce fertile offspring with each other

Question 9

Define Genetic Drift:

Answer 9

A change in the genetic frequency of a population due to random chance as opposed to selection pressures

Question 10

Define Allele Frequency:

Answer 10

The number of times a particular allele appears in a population

Question 11

Define Deme:

Answer 11

An interbreeding sub population is a species that shares a distinct genetic identity. They are more likely to breed with individuals in this group rather than other groups, but they are not reproductively isolated. They are usually geographically or ecologically isolated.

Question 12

Define Allopatric Speciation:

Answer 12

The process by which a single species splits into two or more new species due to geographic isolation

Question 13

Define Sympatric Speciation:

Answer 13

The process by which a new species evolves from the same geographical area due to biological RIMs like genetic mutations, behavioural differences or ecological reasons.

Question 14

Define Mutations:

Answer 14

A permenant change in the DNA base sequence of an organism that can lead to genetic diversity.

Question 15

Define Founders Effect:

Answer 15

When a smaller group of individuals migrate to a different location away from their founding population and establish their own population with a different set of selection pressure.

Question 16

Define Geographic RIM:

Answer 16

A RIM where interbreeding is prevented due to physical barriers

Question 17

Define Ecological RIM:

Answer 17

A RIM where species have different niches in the same region, they won’t run into each other to breed due to preferences.

Question 18

Define Temporal RIM:

Answer 18

A RIM where the species won’t interact due to different preferences in seasons/times to mate

Question 19

Define Behavioural RIMs:

Answer 19

A RIM where differences in behaviour will prevent interbreeding between two species

Question 20

Define Structural RIM:

Answer 20

A RIM where two organisms from different species have non-corrosponding reproductive parts

Question 21

Define Gamete Incompatibility:

Answer 21

A RIM where one population’s sperm cannot fertilise the egg of another population, vice versa

Question 22

Define Hybrid Inviability:

Answer 22

A RIM where the hybrid dies pror to sexual maturity / is miscarried and cannot reproduce

Question 23

Define Hybrid Breakdown:

Answer 23

A RIM where the hybrid is initially fertile, but fertility is eventually diminished with each successive generation

Question 24

Define Hybrid Sterility:

Answer 24

A RIM where the hybrid reaches maturity, but is unable to produce their own fertile offspring

Question 25

Define Ploidy:

Answer 25

The general number of chromosomes an organism has

Question 26

Define Aneuploidy:

Answer 26

A genetic condition where an organism is either missing some or having extra chromosomes. Not complete sets. More common in animals than Euploidy

Question 27

Define Euploidy:

Answer 27

A genetic condition where complete sets of an organisms chromosomes are represented an unusual number of times.

Question 28

Define Instant Speciation:

Answer 28

This is the rapid formation of a new species within a single generation, typically due to polyploidy or hybridisation

Question 29

Define Polyploidy:

Answer 29

A genetic mutation that results in an organism that has 3 or more complete sets of chromosomes. Creates instant speciation, common in plants.

Question 30

Haploid:

Answer 30

n

Question 31

Diploid:

Answer 31

2n

Question 32

Triploid:

Answer 32

3n

Question 33

Tetraploid:

Answer 33

4n

Question 34

Monosomy:

Answer 34

2n - 1 Missing 1 chromosome

Question 35

Trisomy:

Answer 35

2n + 1 1 extra chromosome

Question 36

How can Polyploidy develop?

Answer 36

Errors in Meiosis / Mitosis (cell division) Hybridisation between species (two different species breed, offspring could end up with a different number of chromosomes)

Question 37

How can Polyploidy make an infertile offspring (caused by hybridisation) become fertile?

Answer 37

Polyploidy is a form of cell duplication, so each chromosome would have a partner to pair with and become fertile

Question 38

Define Non-disjunction:

Answer 38

Any errors in cell division when chromosomes fail to seperate

Question 39

Define Autopolyploidy:

Answer 39

When an organism has extra sets of chromosomes from the same species due to non-disjunction. Common in plants, only able to reproduce with other polyploids

Question 40

Define Allopolyploidy:

Answer 40

hybridisation occurs and the hybrid's combined chromosome sets undergo duplication, leading to a new species with multiple sets of chromosomes from both parents. Common in plants,

Question 41

Define Evolution:

Answer 41

The thoery that all terrestrial organisms have their origins in other preexisting ancestors

Question 42

What is a Fossil?

Answer 42

Preserved remains or imprints of an organism that lived in the past

Question 43

Define Fossil Record:

Answer 43

The record of occurence and evolution of living organisms through geological time as inferred through fossils

Question 44

What is Strata?

Answer 44

Layers of sedimentary rocks, older layers are deeper in the earth and newer layers are closer to the surface. Allows us to infer the time relationships of fossils nearby.

Question 45

Define Transitional Organisms:

Answer 45

Organisms / species that fills the gap between 2 seperate species and shows us that a new species didn't spring into existence

Question 46

Define Comparative Anatomy:

Answer 46

Comparing the body parts of different organisms

Question 47

Define Homologous Structures:

Answer 47

Organs that are similar in structure but serve different purposes

Question 48

Define Vestigal Organs:

Answer 48

Organs that are reduced or have no use in the organism they are in, they suggest that it was inherited from ancestors which did need it

Question 49

Define Adaptive Radiation:

Answer 49

Adaptive radiation is the rapid evolution of a single ancestral species into multiple different species, each adapted to a unique ecological niche.

Question 50

Define Convergent Evolution:

Answer 50

When two unrelated species develop similar traits or adaptions due to environmental pressures

Question 51

Define Divergent Evolution:

Answer 51

When two related species evolve different traits due to different environmental pressures

Question 52

Define Co-evolution:

Answer 52

Reciprocal evolutionary changes between two (or more) species that interact closely

Question 53

Define Embryology:

Answer 53

The study of developing embryos in different species, similar development in embryos indicates common ancestry

Question 54

Define Biogeography:

Answer 54

The distribution of species across geographical areas, showing how species evolve and adapt to their environments over time

Question 55

Define Direct Observation:

Answer 55

Evolution that can be analysed during a short period of time

Question 56

Define Rate of Evolution:

Answer 56

Refers to any patterns that occur in a phylogenetic tree that show the rate at which the morphology of organism changed

Question 57

Define Gradualism:

Answer 57

Slow but constant rate of change in the morphology of species over time in response to different selection pressures. Many transitional forms

Question 58

Define Punctuated Equilibrium:

Answer 58

Long periods of time with no or very little morphological change but then followed by short busts of intense morphological change. very few transitional forms

Question 59

How can new niches occur?

Answer 59

1. ancestral population migrates to a new geographical area 2. extinction of organisms that fills available niches, making the niches available to the ancestral species

Question 60

Define mtDNA:

Answer 60

mtDNA or mitochondrial DNA is the DNA located in the mitochondria. Only inherited from the female parent. It doesn't undergo independent assortment or crossing over so it keeps a detailed record of ancestral DNA as most of it is nearly unchanged.

Question 61

Define Y chromosome DNA:

Answer 61

Genetic material located on the Y chromosome, only inherited from the male parent. Can undergo recombination and is prone to accumulating mutations. Large portions of the Y chromosome can be lost throughout the years so it is less stable.