UNIT 1: EVOLUTION AND PHYLOGENETICS (18&20)

Question 1

Evolution

Answer 1

• The gradual change over time; happens in all kinds of things
• Organisms are static and do not change

Question 2

Theory

Answer 2

• The way an organism uses anatomical traits is based on the demands of their environment. Based on this use or disuses, their offspring will be born with modified traits that can better deal with those demands (this theory is wrong)
• Inheritance for acquired traits
• Jean-Baptiste Lamarck (1809)

Question 3

Natural selection

Answer 3

1) Traits are passed from parent to offspring
2) More offspring are produced than can survive
This is due to limited resources such as food, space, mates, etc.
3) Offspring vary in their traits
- Offspring will compete for these limited resources the better competitors survive, and the survivors’ traits are passed on (survival of the fittest)
- If you die; traits font get passed on
- If you survive; your traits get passed on

Question 4

Species

Answer 4

• A group of individual organisms that interbreed and produce viable, fertile offspring
• Natural selection explains difference between species
• Darwin observed patterns in species based on his travels

Question 5

Speciation

Answer 5

• Occurs when a group within a species separates from other members of its species and develops its own unique characteristics

Question 6

Reproductive Isolation

Answer 6

• Enough differences accumulate that they cannot/will not interbreed if reintroduced (separate groups of a population so they can mate which leads to differences so eventually those differences are so different so then they can’t breed together again)

Question 7

Biological Species Concept

Answer 7

• When two different organisms can reproduce with one another, but are reproductively isolated from other organisms (tiger + lions = ligers)

Question 8

Phylogenetic Species Concept

Answer 8

• An evolutionary divergent lineage (branch), one that has maintained its hereditary integrity through time and space

Question 9

Evolutionary Species Concept

Answer 9

• Organism which maintains their morphological (morpho means form) identity from other organisms through time and over space

Question 10

Types of Speciation

Answer 10

1) Allopatric Speciation
2) Sympatric Speciation

Question 11

Allopatric Speciation

Answer 11

• Speciation by geographic isolation
• Geographic separation of a population from a parent population
• They have different homes which is why they’re different

Question 12

Dispersal

Answer 12

• When a few members of a species move to a new geographical area

Question 13

Vicariance

Answer 13

• Change in the environment to physically divide organisms (seperated due to mountain range or river)

Question 14

Adaptive Radiation

Answer 14

• An evolutionary process that produces new species from a single, rapidly diversifying lineage

Question 15

Sympatric Speciation

Answer 15

• The evolution of a new species from a surviving ancestral species while both continue to inhabit the same geographic region
• There are no physical barriers needed

Question 16

Reproductive Isolation

Answer 16

• The inability of two populations to interbreed and produce offspring

Question 17

Prezygotic Barrier

Answer 17

• A mechanisms that blocks the gametes from ever meeting

Question 18

Postzygotic Barrier

Answer 18

• Barriers that occur after a zygote has formed and reduce the viability of the hybrid zygotes or offspring

Question 19

Gamete Barrier

Answer 19

• Differences in gamete cells (eggs and sperm) prevent fertilization from taking place

Question 20

Habitat isolation

Answer 20

• Populations that moved to a new habitat that no longer overlaps with the same species’ other populations

Question 21

Behavioral isolation

Answer 21

• Occurs when the presence or absence of a specific behavior prevents reproduction

Question 22

Phylogenetics

Answer 22

• The study of evolutionary relationships among biological entities – often species, individuals or genes
• The Taxonomic Hierarchy

Question 23

Phylogenetics Order

Answer 23

• Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species

Question 24

Phylogentic Trees

Answer 24

• First created by darwin
• Explained the realtionship between species
• A phylogeny is a fancy way of saying family tree
• A diagram used to reflect evolutionary relationships of a organisms or groups of organism

Question 25

Branch Point

Answer 25

• A point at which two evolutionary lineages split from a common ancestor

Question 26

Basal Taxon

Answer 26

• A lineage that evolved early from the root that remains unbranched

Question 27

Sister Taxa

Answer 27

• Two lineages stemming from the same branch point

Question 28

Polytomy

Answer 28

• A branch with two or more than two lineages
• More than 2 is a polytomy
• Not accurate

Question 29

Homologous

Answer 29

• Structures that share a similar embryonic origin (humerus bone analogy in different animals) (use this to define trees)

Question 30

Analogous

Answer 30

• Structures that have a similar function (wings used to fly) (don’t use this to define trees)

Question 31

The phylogenetic tree concept

Answer 31

• A single trunk representing a common ancestor
• Branches representing the divergence of species from this ancestor
• Classification of organisms into classes based on the last common ancestor

Question 32

What determines a tree?

Answer 32

• Morphology
• DNA
• Computer Algorithms

Question 33

Maximum Parsimony

Answer 33

• The more similar the more closely related they are

Question 34

Horizontal Gene Transfer

Answer 34

• The introduction of genetic material from one species to another species
• Other than by vertical transmission (parent to offspring)
• Swapping genes with someone from same generation
• No new generation is made
• The transfer of genes between unrelated organisms

Question 35

Horizontal Gene Transfer Methods

Answer 35

1) Transformation- bacteria makes up naked DNA
2) Transduction- a virus transfers the genes
3) Conjugation- a hollow tube transfers gene between organisms (swap some DNA with each other)

Question 36

Monophyly

Answer 36

• Includes recent common ancestor and all descendants

Question 37

Paraphyly

Answer 37

• Includes recent common ancestor but not all descendants

Question 38

Polyphyly

Answer 38

• Does not include recent common ancestor or all descendants