Distributions and life history

Question 1

Questions of Distribution (Biogeography)

Answer 1

What factors limit the geographic ranges of species?

What factors influence the distribution of populations
within species ranges?

Question 2

What factors limit the geographic ranges of species?

Answer 2

-climate (physiological adaptations)
-nutrient/food availability
-interspecific interactions
-dispersal ability/mobility
-historic factors (e.g., glaciations)

Question 3

What factors influence the distribution of populations
within species ranges?

Answer 3

-microclimate variation (temp and moisture vary)
-nutrient/food availability (can be patchy)
-interspecific interactions (can be local; anthropogenic)
-dispersal ability/mobility (some areas are inaccessible)
-historic factors (e.g., fire)

Question 4

Distribution types of individuals within a population…

Answer 4

Clumping, Uniform, Random

Question 5

Clumping distribution is…

Answer 5

The most common.
Safety in numbers
social interaction
mating
Caring for young resources are clumped
-poor/low disposal

Question 6

Uniform distribution is…

Answer 6

Not as common.
Used because of the scarcity of resources
Reflects interactions between individuals
Competition for resources
Territoriality

Question 7

Random distribution is…

Answer 7

Quite rare
It can be hard to determine between truly random or “largely clumpy.”

Question 8

Slimy salamanders are found near flowing water and are territorial, with each male holding a similarly-sized territory. Over a geographic area of 100 km2. Which of the following is likely to characterize the distribution of slimy salamanders?

1. Clumped
2. Uniform
3. Random

Answer 8

Uniform distruibution

Question 9

Life History Traits are…

Answer 9

phenotypes that affect the life history strategy of an individual

Question 10

Life History Strategy is…

Answer 10

• age-specific schedule of survival and reproduction
• determined by the distribution of energy across
  survival, growth, and reproduction at different ages

Question 11

How life history and strategy relate

Answer 11

Life History Traits -> Life History Strategy -> Population-level distribution & abundance

Question 12

Life History Trait examples…

Answer 12

Size and age at sexual maturity
Offspring number
Offspring size
Life span

Question 13

Darwinian Demon is…

Answer 13

• Reproductive at birth
• Produces an infinite number of offspring
• Lives forever

Question 14

The Optimal Life History Strategy varies with ecological characteristics…

Answer 14

Abiotic conditions
Resource availability
Community composition
and how these (and any other factors) influence the age-specific probability of survival

Question 15

High adult (low juvenile) mortality rates:

Answer 15

selection favors high levels of energy allocation to reproduction, early age at sexual maturity, many offspring, small offspring*

Question 16

• High juvenile (low adult) mortality rates:

Answer 16

Juveniles put more energy into growth (get big!) than into reproduction, fewer offspring, large offspring

Question 17

How do guppies in juvenile-predation environments
differ from those in adult-predation environments?

Answer 17

C. They have larger offspring.

Question 18

Life tables tell us:

Answer 18

• At what age do individuals face the lowest/highest mortality risk?
• Population growth rate
• Estimated future population size

Question 19

Cohort Life Table

Answer 19

follows cohort of individuals

Question 20

Static Life Table

Answer 20

estimates of age structure and vital rates as a snapshot in time

Question 21

Is the population of females in the U.S. growing?

A. Yes
B. No

Answer 21

YES