Population Dynamics and Growth

Question 1

What could cause populations of invasive species to grow exponentially?

Answer 1

-Lack of predators
-Lack of disease
-New niches to exploit
-Reduced competition from native species

Ex: Asian Carp

Question 2

Demography

Answer 2

The study of population abundance in varying age categories; this is how scientists track population growth

Question 3

Quadrats

Answer 3

Can be set up in the field to determine the absolute number of individuals in an area.

Question 4

Mark/Recapture

Answer 4

Can assist with animals that are very mobile.

Question 5

Life Tables

Answer 5

Examine abundance in various age classes.

Question 6

Type 1

Answer 6

High survival early on, rapidly declines later on

Ex: Humans

Question 7

Type 2

Answer 7

Linear survival

Ex: Birds

Question 8

Type 3

Answer 8

Low survival early on, slowly declines later on

Ex: Trees

Question 9

Logistic (restricted) growth stages

Answer 9

-Rate accelerates
-Point of maximum growth reached
-Rate slows down
-Carrying capacity of environment reached

Question 10

What could limit population growth?

Answer 10

-Population density: Competition for resources would eventually limit growth, and buildup of waste would become fatal
-Carrying capacity: Optimal size of a population that environment can maintain

Question 11

Density-Dependent Factors

Answer 11

Food
Water
Shelter
Nesting Space
Mates
Build up of waste products

Question 12

Density-Independent Factors

Answer 12

Weather
Natural Disasters
Pollution

Question 13

Characteristics of K-selected species

Answer 13

-Mature later
-Greater longevity
-Increased parental care
-Increased competition
-Fewer, larger offspring

Question 14

Characteristics of r-selected species

Answer 14

-Mature early
-Lower longevity
-Decreased parental care
-Decreased competition
-More, smaller offspring

Question 15

What factors will limit population growth in humans?

Answer 15

-Limits to food resources
-Increased Transmissible Disease
-Waste accumulation, which could lead to increases in diseases such as cancer
-Global climate change as a result of greenhouse gas emissions

Question 16

Interspecific competition

Answer 16

Competition between two species for resources – usually not direct battle, but rather one species evolves the ability to become more efficient than another at gaining resources.

Question 17

Predation

Answer 17

When one species consumes another. This can also extend to plant/herbivore relationships.

Evolved patterns based on predation:
Camouflage
Chemical warfare
Warning coloration
Mimicry
behavioral strategies

Question 18

Parasitism

Answer 18

One species (the parasite) feeds off of another organism (the host).

Ectoparasites – live on the outersurface of the host organism

Endoparasites – live inside the host organism

Question 19

Coevolution

Answer 19

When two species interact over long periods of time and changes in the gene pool of one species lead to changes in the gene pool of the other.

Oscillatory Dynamics

Question 20

Commensalism

Answer 20

An interaction that benefits one but has little, if any, beneficial or harmful effect on the other.

Question 21

Mutualism

Answer 21

Two species are both benefitted by the interaction.

Question 22

Red Queen Hypothesis

Answer 22

One of the key advantages of sexual reproduction is that it generates genetic diversity within populations, allowing for the rapid evolution of traits that can help organisms adapt to changing environments and overcome coevolutionary pressures. The Red Queen Hypothesis suggests that this rapid evolution is necessary because parasites, in particular, are constantly evolving to overcome their host’s immune defenses, and hosts must adapt to stay ahead of the parasites.

Question 23

Keystone species

Answer 23

Species that have a large impact relative to their biomass.

Ex: Seastars

Question 24

Dominant species

Answer 24

Constitute a large fraction of a community’s biomass and whose impacts are large, but not disproportionate to their abundances.

Question 25

Primary succession

Answer 25

Succession from new land that has formed, usually starts on bare rock.

Example: New island formation from explosion and depositing of molten rock.