Lecture Exam 1

Question 1

What is a species? Defend your answer.

Answer 1

-While there is no singular definition of a species, I believe that a species is a group of individuals that breed naturally and is stable throughout time.
- Biological species = “potentially interbreeding natural populations” → most common definition

Question 2

What are the assumptions of the general theory of evolution?

Answer 2

-Non-living things gave rise to living things (spontaneous generation; why has it not happened again?)
-Spontaneous generation occurred only once (why not more than once?)
-All life is interrelated
-Protozoa gave rise to Metazoa
-Invertebrate phyla are interrelated
-Invertebrates gave rise to vertebrates
-Vertebrates gave rise to other vertebrates

Question 3

Compare and contrast cladistics and phenetics.

Answer 3

Compare:
-Both are branches of Phylogeny (historical relationships of organisms)
-Both methods are not quantitative
-Both methods have different “scenarios” for the same organism
Phenetics:
-Collecting a series of measurements (can be from anywhere on the organism)
-Relationships are based on overall similarity; the more similar two species are, the more closely related they are
Cladistics:
-Cladistics suggest that relationships cannot be determined by overall similarity
-Relationships are determined by shared DERIVED characters (the more recent the character, the more evolved)
-Requires us to look at what a primitive and derived character is
-Outgroup comparison

Question 4

Describe vicariance biogeography

Answer 4

-Part of the Cladistic revolution is the notion that phylogenies also predict earth history
-Is a quantitative, testable method
-It revitalizes the field of systematics, coupling phylogeny reconstruction with geographic history and adds to the field and adds to the field of science dealing with evolution

Question 5

Describe the mechanisms that determine the distribution of vertebrates.

Answer 5

-Faunal: prepare faunal lists of animal populations for specific areas; forms the basis for all zoogeographic research (just try to figure out what’s there)
-Comparative: classify distributions according to external features (grouping based on traits and geography
-Geographic Range: compare distances where found between two species
-Ecological Distribution: what is found in a certain climate

Question 6

Discuss Pough’s strategies to being a vertebrate.

Answer 6

-Two Hypothesis: Low Energy Flow vs. High Energy Flow
-Low Energy Flow:
-fish amphibians, reptiles
-Ectothermy: avoid insulation to allow blood to be heated from environment
-Anaerobic Respiration during exercise; short bursts of activity; long recovery to convert lactic acid
-Low Resting Metabolism: low maintenance energy; relatively impermeable cell membranes; no need for oxygen during exercise; small brains
-MOST of energy consumed converted to biomass (growth or reproduction)
-High Energy Flow:
-birds, mammals
-Endothermy: requires insulation to minimize maintenance energy
-Aerobic respiration during exercise due to relatively permeable cell membranes; long, sustained recovery
-High Resting Metabolism
-High Maintenance energy
-relatively permeable cell membranes
-large brains (nervous tissue requires much oxygen)
-Most of energy consumed lost to maintenance, little to no growth or reproduction-average=1.4%