Systematics And Phylogentic Revolution

Question 1

What are all organisms composed of?

Answer 1

–Are composed of one or more cells
–Carry out metabolism
–Transfer energy with ATP
–Encode hereditary information in DNA

Question 2

What is classification?

Answer 2

Multilevel groping of individuals .

Question 3

Who first classified organisms ? How?

Answer 3

By Aristotle over 2k years ago. Written in Latin and formed by their genus.

Question 4

Who replaced polynomial system? What is it? What did he change it to?

Answer 4

by Linnaeus about 250 years ago.
–polynomial - strings of Latin words and phrases containing up to 12 words
–binomial - two-part name for each species

Question 5

What is taxa?

Answer 5

group of organisms at a particular level in a classification system (taxonomy)

Question 6

Convention of taxonomy ?

Answer 6

–first word of binomial name is genus and is always capitalized
–second word refers to particular species and is not capitalized
together form scientific name, written in italics

Question 7

The taxonomic Hierarchy in order is?

Answer 7

Domain-Kingdom-phylum-class-order-family-genus-species

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Question 8

What is systematics?

Answer 8

reconstruction and study of evolutionary relationships

–construct phylogeny by looking at similarities and differences between species

Question 9

What is phylogenetics? (Phylogeny)

Answer 9

Study of evolutionary relationships among groups of organisms. Evolutionary history of species. Includes species that are closely related and in what order related species evolved.

Question 10

What is cladistics ?

Answer 10

distinguishes ancestral from shared characters
§only shared derived characters are considered in determining evolutionary relationships
- taxonomy method for creating hierarchies of organisms.

Question 11

How did Darwin depict his hypothesis of all species deriving from a common ancestor?

Answer 11

Cladogram. Represents phylogeny, depicts evolutionary relationships.
–Twigs of tree represent existing species
–Joining of twigs and branches reflects common ancestry

Question 12

What is convergent evolution?

Answer 12

two unrelated species evolve similarly, occurs when:

• use similar habitats
• similar environment pressures.

Question 13

What is evolutionary reversal?

Answer 13

process in which a species re-evolves characters of an ancestral species.

Question 14

What is derived character?

Answer 14

similarity that is inherited from most recent common ancestor of an entire group.

Question 15

What is ancestral character?

Answer 15

similarity that arose prior to common ancestor of the group.

Question 16

What is a character in cladistics?

Answer 16

any aspect of the phenotype:

   - Morphology    - Physiology
   - Behavior        - DNA

Question 17

What is character states?

Answer 17

recognizable forms of a character:
–Example: Teeth (character) in amniote vertebrates has two character states, present in most mammals and reptiles and absence in birds and turtles
Character: teeth
States: present, absent

Question 18

What is polarization of a character?

Answer 18

determine if a character is ancestral or derived
–Example: polarize “teeth” means to determine presence or absence in the most recent common ancestor
•Outgroup comparison is used to assign character polarity

Question 19

What is an outgroup?

Answer 19

species or group of species closely related to, but not a member of, the group under study.
Do not always exhibit the ancestral condition. Because the outgroup also evolved from ancestor.

Question 20

What is a Clade?

Answer 20

species that share a common ancestor as indicated by possession of shared derived characters.
Clades are evolutionary units and refer to a common ancestor.

Question 21

What is synapomorphy and plesiomorphy?

Answer 21

Synapomorphy is a trait that is shared by two or more taxa and their most recent common ancestor .
Plesiomorphy is ancestral trait.

Question 22

What is Homoplasis?

Answer 22

Shared character state that has not been inherited from a common ancestor.
- results from convergent evolution or evolutionary reversal.

Question 23

What is the principle of parsimony ?

Answer 23

Process of characterizing organisms by common traits and traits that make them different. Quickest way possible. Shortest steps.
Like birds and insect.
Wings are behind first part but feathers would separate the two.

Question 24

What is the molecular clock?

Answer 24

rate of evolution of a molecule is constant through time
Used to determine time since branching occurred on cladogram
But rate of evolution is not constant, so method no weak when used alone

Question 25

What is classification in systematics?

Answer 25

organization of species within the taxonomic hierarchical system
–Domain, kindgom, phylum, class..

Question 26

What is monophyletic group?

Answer 26

includes the most recent common ancestor of the group and all of its descendants (clade).

Question 27

What is paraphyletic group?

Answer 27

includes the most recent common ancestor of the group, but not all of its descendents.

Question 28

What is polyphyletic group?

Answer 28

does not include the most recent common ancestor of all the members.

Question 29

Biological species concept (BSC) is defined as ?

Answer 29

defines species as groups of interbreeding population that are reproductively isolated from other groups.

Question 30

Phylogenetic species concept (PSC) is defined as ?

Answer 30

defines species as groups with shared derived characters

–Applied to groups of populations that have been evolving independently of other groups

Question 31

What is comparative biology?

Answer 31

determine phylogenetics of species through comparative studies of development, genomics, physiology, and ecology

Question 32

What are Homologous structures?

Answer 32

derived from common ancestor (e.g. dolphin flipper and horse leg) but serve different purposesParental care in dinosaurs, birds, crocodiles

Question 33

What are homoplastic structures? (Analogous)

Answer 33

not derived from common ancestor, instead from convergent evolution
–Wings of birds and insects

Question 34

What is species richness?

Answer 34

Greater number of species per Clade.

Ex: 60% of all animals are insects and 80% of all insects are beetles (order Coleoptera)

Question 35

What are some explanations of phylogenetics for beetle species richness?

Answer 35

–Not the evolution of herbivory
–Diversity of plants to feed upon lead to evolution of new beetles to feed on angiosperms
–Angiosperm eating beetles evolved 5 times independently
–Angiosperm specializing clade is more species-rich than other clades probably due to large angiosperm diversity