Evolution & Classification

Question 1

Timeline: How Long ago was the Earth formed?

Answer 1

4.5+ BYA

Question 2

Timeline: How old are the oldest prokaryote fossils? What were they?

Answer 2

3.5 BYA

cyanobacteria

Question 3

Timeline: How old are the oldest Unicellular eukaryote fossils? What were they?

Answer 3

1.8 BYA

dinoflagellates

Question 4

Timeline: When did the earliest metazoa evolve?

Answer 4

670 MYA - 1.2 BYA ???

Question 5

Timeline: How old are the oldest sponge & invertebrate embryo fossils?

Answer 5

570 MYA

Question 6

Timeline: How old are the oldest vertebrate fossils?

Answer 6

550 MYA

Question 7

Timeline: When did the cambrian explosion occur?

Answer 7

540 MYA

Question 8

Timeline: the 1st terrestrial arthropods evolved how long ago?

Answer 8

425 MYA

Question 9

Timeline: The 1st wingest insects and earliest terrestrial tetrapods (vertebrates) evolved how long ago?

Answer 9

413 MYA

Question 10

Timeline: Dinosaurs appeared how long ago?

Answer 10

225 MYA

Question 11

Timeline: Birds appeared how long ago?

Answer 11

185 MYA

Question 12

Timeline: Hominids (“Ardi”) appeared how long ago?

Answer 12

4.4 MYA

Question 13

Timeline: How long ago did Homo sapiens appear?

Answer 13

~0.4 MYA

Question 14

What is classification?

Answer 14

arrangement into groups according to established criteria

Question 15

What is Biological Classification?

Answer 15

grouping beings according to their actual evolutionary relationship.

Question 16

What is systematics?

Answer 16

grouping of species by similarity & evolutionary relatedness

Question 17

What is binomial nomenclature?

Answer 17

every species is given a 2 part name
species name = Genus + specific epithet
ex) Homo sapiens

Question 18

What is a Biological species?

Answer 18

members of a species reproduce with each other but do not interbreed with other species. subspecies arising through geographic separation can still interbreed with viable offspring but slight gene diff

Question 19

Name the hierarchical classification in order.

Answer 19

Kingdom, Phylum, Class, Order, Family, Genus, Species

Question 20

What data is used for classification?

Answer 20

Morphology
Ecological characteristics
fossils
molecular information

Question 21

What is morphology?

What is the problem with using it for classification?

Answer 21

external & internal anatomy,embryology

Problem: if similar morphology not due to close relationship

Question 22

What is convergent evolution?

Answer 22

This is when 2+ species evolve the same feature, separate from one another.
(ie. they have a common ancestor w/o the feature)

Question 23

When a feature evolves more than once, what is it called? Give an example.

Answer 23

analogous

“Wings” - birds & bats

Question 24

What is a homologous feature? Give an example.

Answer 24

a feature present in a common ancestor

“forelimbs” - birds & humans

Question 25

What are some ecological characteristics? | What is the problem with using this for classification?

Answer 25

Habitat, niche, behavior, phenology, geographic range Problem: best for lower categories (ie. genus)

Question 26

How is the fossil record useful in classification? | what is the problem with using it for classification?

Answer 26

Usefulness: helps determine sequence of appearance, useful for extinct species (common ancestors) & good record of taxa with hardened body problem: only ~10% of invertebrates fossilize well

Question 27

What is molecular evidence in classification?

Answer 27

Physiological: enzyme structure, biochemical pathways Genetic: chromosonal banding patterns, DNA sequence

Question 28

What is the problem with using molecular evidence for classification?

Answer 28

Difficult to detect convergent evolution difficult to extract DNA mutation rates not known for all taxa rates very w/in geologic periods (punctuated equilibrium)

Question 29

What is the exaptation concept?

Answer 29

New complex adaptations don't appear in a single mutation. Adaptations are modifications of preexisting inherited structure that may have evolved for other purposes. New adaptations evolve in progression of useful intermediate stages

Question 30

What is the evolution of feathers? State the possible intermediate stages.

Answer 30

Cold-blooded dinosaurs with flattened scale for protection. IS: insulation for warm-blooded dinosaurs IS: Sexual displays Winged Dinosaur glides w/feathered forelimb Birds diverge, specialized for flight

Question 31

Explain the lifecycle of the Unionid Clam.

Answer 31

Adults nearly sessile sperm is expelled & taken in by female gravid female grows a fish lure fish bites lure causing clam to spray larvae into its mouth larvae attach to gills then drop at maturity

Question 32

name the 3 classification methods

Answer 32

"Classical" taxonomy Phenetics Cladistics

Question 33

What is the goal of Classical taxonomy? | What is the problem?

Answer 33

compares the morphology of "best" features (based on expert opinion) to find overall similarity and relatedness problem: expert opinion is subjective. bad traits may be chosen (ex. "wings" belong to bats & birds; convergent evolution)

Question 34

What is the goal of Phenetics? | made in 1950s

Answer 34

eliminate subjectivity, classify by similarity not based on relatedness as many traits as possible are used in computer programs to calculate similarity index; shows "best fit" evolutionary biologists hate this

Question 35

What is the diagram in Phenetics called?

Answer 35

Phenogram

Question 36

What is the problem with phenetics?

Answer 36

- different computer programs calculate "best fit" differently - ignores evolutionary relationships - uses convergent characteristics

Question 37

What is the goal of Cladistics? | made in 1950s-60s

Answer 37

Eliminate subjectivity, show relatedness - uses many traits, but only ones showing evolutionary relationships - computer programs estimate relatedness

Question 38

What is the diagram in cladistics called?

Answer 38

cladogram

Question 39

What is a monophyletic group?

Answer 39

a complete group and all their decendents that have the same ancestor reptiles are not monophyletic, birds evolved from them

Question 40

What is an apomorphic feature?

Answer 40

Wings, modified scales feature that evolved within a group

Question 41

What is a pleisiomorphic feature?

Answer 41

scales feature that evolved at the base of a study group