Exam 3

Question 1

Taxonomy

Answer 1

science of classifying organisms into taxa with a traditional Linnaean system (after Carl Linnaeus) uses a nested hierarchical system

At each sublevel in the taxonomic classification system, organisms become more similar.

Question 2

Binomial nomenclature

Answer 2

Species name = genus + species ‘epithet’

Question 3

Biologists group organisms based on shared characteristics. What are the 6 traits?

Answer 3

Fossil records
Morphology
Physiology
Behavior
Embryological development
DNA/RNA sequences

Question 4

Phylogenetic systematics

Answer 4

Reconstruction and study of evolutionary relationships

Question 5

Phylogeny

Answer 5

Hypothesis about relationships among taxa
Depicted as a phylogenetic tree or cladogram
A branching diagram depicting evolutionary relationships

Question 6

Taxon (taxa, pl)

Answer 6

group(s) of organisms (species, family, domain, etc.)

Question 7

Clade

Answer 7

any branch or lineage (lines in cladogram)

Question 8

Branch point (node)

Answer 8

splitting represents single lineage evolving into two clades

Nodes are most recent common ancestor (MRCA) of subsequent clades

Question 9

Limitations of cladograms

Answer 9

Often, closely related taxa look similar, but not always

If evolved under different circumstances (selection pressures), the taxa may look very different despite their close relation

Unless specified, the length of the clade does not indicate amount of time passed since divergence (node)

Question 10

Two Options for Similarities

Answer 10

Homologous characters
Analogous characters

Question 11

Analogous characters

Answer 11

Similar due to functional or ecological constraints/pressures
Characters can be very similar in appearance due to convergent evolution
Convergence occurs in unrelated (or distantly-related) taxa when characters are shaped by similar ecological or evolutionary constraints (selection pressures)
May be referred to as ‘homoplasy’ (instead of homology)

Question 12

Homologous characters

Answer 12

Similar due to divergent evolution (same ancestral source)
Based on genetics and developmental origin
The deeper the similarity, the more likely it’s of same origin

Question 13

Monophyletic groups (monophyly)

Answer 13

the most recent common ancestor and all descendants
According to cladistic analysis, only monophyletic groups should be named and recognized

Question 14

Building Phylogenetic Trees

Answer 14

All organisms within a clade share an exclusive point (node) on the tree.

A clade may contain multiple groups, as in the case of animals, fungi and plants, or a single group, as in the case of flagellates.

Groups that diverge at a different branch point, or that do not include all groups in a single branch point, are not considered true clades.

Question 15

Ancestral character state (aka plesiomorphy)

Answer 15

The character state present in a lineage immediately before a character state change

Found in common ancestor of taxa, but not all displayed taxa have it
Basal clade taxon is expected to display most ancestral character states

Question 16

Shared derived character state (aka synapomorphy)

Answer 16

Arose (derived) within the larger clade
Distinguishes taxa that share it from those that do not
Provides information about relatedness within the larger group
Used to identify branch points (nodes) within the larger clade

Question 17

Rule of parsimony

Answer 17

Prefer the simplest cladogram with the fewest steps or events

Question 18

Two patterns of evolution that may be misleading

Answer 18

Convergent evolution
Evolutionary reversal

Question 19

Convergent evolution

Answer 19

Structures evolving from same evolutionary pressures but not from a common ancestral trait
Example: wings in birds and wings in insects
Example: leglessness in (some) lizards and leglessness in snakes

Question 20

Evolutionary reversal

Answer 20

Ancestral traits are sometimes lost in descendants in one group
Example: loss of limbs in snakes (most other squamates have legs)
Example: loss of hindlimbs in cetaceans

Question 21

6 reasons why do phylogenies matter?

Answer 21

1. Understanding of evolutionary processes
2. Research on related species may help to better understand human health, medical issues
3. Track evolution of parasites and viruses
4. Use biotechnology to produce more productive crops, domesticated animals
5. Produce more effective drugs (e.g. human insulin)
6. Improve conservation efforts for threatened and endangered species

Question 22

Organismal Ecology

Answer 22

Study of adaptations that enable individuals to live in specific habitats. These adaptations can be morphological, physiological, and behavioral.

Question 23

Population Ecology

Answer 23

Study of demography and intraspecific interactions; includes the number of individuals in an area and how and why population size changes.

Question 24

Community Ecology

Answer 24

Study of interspecific interactions at small and large scales (e.g., symbiosis and succession, respectively

Question 25

Ecosystem Ecology

Answer 25

Study of the storage and movement of nutrients and energy among organisms and the surrounding atmosphere, soil, and water.

Question 26

Landscape Ecology

Answer 26

Study of biomes and the conditions that influence their dispersion.

Question 27

Biogeography

Answer 27

the study of the geographic distribution of living things and the abiotic factors that affect their distribution.

Question 28

endemic species

Answer 28

one which is naturally found only in a specific geographic area that is usually restricted in size.

Question 29

cosmopolitan species

Answer 29

species which live in a wide variety of geographic areas.

Question 30

Abiotic Factors affecting distribution

Answer 30

Energy Sources Sunlight Ocean Upwelling Temperature Presence, Type, and Changes in Water Freshwater Saltwater Frozen water Seasonal water changes Nutrients and Inorganic Materials Other factors: Aquatic: Oxygen, salinity, currents, tides, vents Terrestrial: Fire, wind Both: Volcanism, tectonics, natural events

Question 31

Ocean upwelling

Answer 31

an important process that recycles nutrients and energy in the ocean. As wind pushes offshore, it causes water from the ocean bottom to move to the surface, bringing up nutrients from the ocean depths.

Question 32

Fire impact

Answer 32

mature cones of the jack pine (Pinus banksiana) open only when exposed to high temperatures, such as during a forest fire. A fire is likely to kill most vegetation, so a seedling that germinates after a fire is more likely to receive ample sunlight than one that germinates under normal conditions

Question 33

Using your understanding of ocean upwelling, explain one reason why marine life is more abundant near some coastlines than others.

Question 34

Draw and label a cladogram depicting the relationships of four taxa (A, B, C, and D). Taxon A occupies the basal clade. Taxa B and C are sister taxa. Indicate the occurrence of a homologous characteristic shared by all taxa (refer to it as ‘cells’). Then indicate the occurrence of an analogous characteristic shared by taxa C and D (refer to it as ‘aerobic’).

Question 35

Use the cladogram below to complete the following: What named group is monophyletic? What ancestor is shared by all displayed taxa? What shared derived character is diagnostic of bilateria?

Answer 35

bilateral symmetry ancestor 1 having bilaterial symmetry

Question 36

Climate

Answer 36

long-term, predictable atmospheric conditions of a specific area

Question 37

Weather

Answer 37

conditions of the atmosphere during a short period of time A specific weather event occurring in a particular region is not evidence of global climate change

Question 38

Different biomes

Answer 38

Tropical forest Desert Tundra Temperate forest Boreal forest -- taiga Temperate grassland Savanna (grasses) Chapparal – scrub forest

Question 39

Aquatic zones in water

Answer 39

Neritic zone (shallow coastline) Intertidal Zone Photic Zone Aphotic zone Abyssal zone Benthic realm

Question 40

If you were to travel up Mount Kilimanjaro in Tanzania, you would pass through several habitats: savanna at the base, forest on the slopes, and tundra near the top. Explain how such diverse habitats can be found at one location near the equator.