Ecology and Population Dynamics: Species Strategies, Growth, and Demographic Transition

What are generalists in ecology?

Organisms that can use a variety of environmental resources and adapt to a wide range of environments.

What are specialists in ecology?

Organisms that use a specific set of resources and are less adaptable due to specialized needs.

How do generalists and specialists differ in terms of extinction risk?

Generalists are less likely to become extinct, while specialists are more likely to become extinct.

What characterizes r-strategists in population dynamics?

They have many offspring, low parental care, mature rapidly, and are not endangered.

What characterizes K-strategists in population dynamics?

They have few offspring, high parental care, mature slowly, and are often endangered.

What is a Type I survivorship curve?

Characterized by low mortality at birth and high probability of surviving to advanced age, typical of humans and elephants.

What is a Type II survivorship curve?

Characterized by fairly uniform death rates across all age categories, typical of rodents and songbirds.

What is a Type III survivorship curve?

Characterized by high mortality rates for younger individuals, typical of species like sea turtles and fish.

What does carrying capacity (K) refer to?

The number of individuals that can be supported sustainably in a given area.

What factors can regulate population sizes in relation to carrying capacity?

Factors include sunlight availability, food availability, nutrient levels, oxygen content, and space.

What is a population dispersal pattern?

The distribution of individuals or species in different spaces over time.

What is a clumped population dispersal pattern?

A pattern where some areas are dense with organisms while others have few members, often found in environments with patch resources.

What is a random population dispersal pattern?

A pattern where individuals are distributed randomly, occurring in habitats with consistent environmental conditions.

What is a uniform population dispersal pattern?

A pattern where space is maximized between individuals to minimize competition.

What is biotic potential?

The maximum reproductive capacity of an organism under optimal environmental conditions.

What is environmental resistance?

Any factor that inhibits the increase in the number of organisms in a population.

What factors can increase biotic potential?

Adaptability, ability to migrate, adequate disease resistance, favorable environmental conditions, and high birth rates.

What factors can decrease biotic potential?

Inability to adapt or migrate, poor disease resistance, unfavorable environmental conditions, and low birth rates.

What is a J-Curve in population growth?

A representation of rapid population growth in a new environment that stops abruptly due to environmental resistance.

What is an S-Curve in population growth?

A representation of population growth that stabilizes near the carrying capacity after initial exponential growth.

What are density-independent limiting factors?

Factors that limit population size regardless of the population density, such as climate and natural disasters.

What are density-dependent limiting factors?

Factors that limit population growth based on population density, including competition and predation.

What is the significance of reproductive success in ecology?

It measures how many organisms are able to mature and reproduce, balancing natural resource limitations and competition.

What is an S-Curve in population dynamics?

It occurs when the population density of an organism initially increases slowly but then stabilizes due to finite resources.

What does the carrying capacity of an environment signify?

It denotes the point at which the upward growth curve of a population begins to level out.

What are positive feedback loops in ecosystems?

They stimulate change and are responsible for sudden or rapid changes within ecosystems.

How do negative feedback loops contribute to population stability?

They provide stability by limiting population growth, often through predation and resource availability.

What is a limiting factor?

It is any resource or environmental condition that limits the abundance, distribution, and/or growth of a population.

What is Liebig's law of the minimum?

It states that the least favorable factor will dictate the growth, abundance, or distribution of a population.

What are density-independent factors?

Factors that limit population size regardless of the number of individuals in the population.

What is the Rule of 70?

It helps explain the time periods involved in exponential population growth occurring at a constant rate.

What is doubling time in population studies?

It is the amount of time it takes for a population to double in size.

How do you calculate doubling time using the Rule of 70?

Doubling time (dt) = 70 / r, where r is the growth rate.

What is the Crude Birth Rate (CBR)?

CBR = (b ÷ p) × 1,000, where b is the number of births and p is the total population.

What is the Crude Death Rate (CDR)?

CDR = (d ÷ p) × 1,000, where d is the number of deaths and p is the total population.

What is the formula for Global Population Growth Rate?

Global Population Growth Rate (%) = [(CBR - CDR)] / 10.

What percentage of the world is malnourished?

25% of the world is malnourished.

What impact does population growth have on biodiversity?

Two-thirds of the world's species are in decline due to human activity.

How does population growth affect coastal ecosystems?

High population densities and urban development stress half of coastal ecosystems.

What is the impact of population growth on forests?

Nearly half of the world's original forest cover has been lost, with 16 million hectares cut annually.

What are the public health implications of population growth?

Over 12 million people die each year from dirty water and poor sanitation, mostly in developing nations.

What are age-structure diagrams?

They are determined by birth rate, generation time, death rate, and sex ratios.

What does a pyramid-shaped age-structure diagram indicate?

It indicates high birth rates with the majority of the population in the reproductive age group.

What does a bell-shaped age-structure diagram indicate?

It indicates that pre-reproductive and reproductive age groups are nearly equal, characteristic of stable populations.

What does an urn-shaped age-structure diagram indicate?

It indicates that the post-reproductive group is largest and the pre-reproductive group is smallest, characteristic of declining populations.

What is the Total Fertility Rate (TFR)?

The average number of children that each woman will have during her lifetime.

Name one factor contributing to the decline in fertility rates.

Greater access to primary healthcare and family-planning services as countries develop.

How has female education impacted fertility rates?

Increasing female educational opportunities have contributed to declining fertility rates.

What trend is observed among millennials regarding marriage?

Many millennials are postponing marriage until their careers are established.

How does urbanization affect family size?

Urbanization increases the cost of living and reduces the need for extra children to work on farms.

What is the Total Fertility Rate of Niger?

7.63

What is the Total Fertility Rate of the USA?

1.87

What factors have reduced human death rates?

Increased food availability, medical advancements, improved sanitation, and better hygiene.

What major human population growth surges occurred due to the use of tools?

The first surge occurred approximately 3.5 million years ago.

What was the human population around 8000 B.C.E.?

Approximately 50 million.

What characterized the population growth from 0 C.E. to 1300 C.E.?

Population increased due to the discovery of new habitats, despite famines, wars, and diseases.

What is the current estimated human population?

Approximately 7.5 billion.

What is the projected human population by 2050?

Estimates are as high as 9.8 billion.

What does demographic transition refer to?

The transition from high birth and death rates to lower birth and death rates as a country develops.

What are the characteristics of Stage 1 of demographic transition?

High birth and death rates due to poor agricultural practices and medical care, resulting in low population growth.

What happens in Stage 2 of demographic transition?

Death rates decline due to medical advances and sanitation, leading to rapid population increase.

What is a key feature of Stage 3 of demographic transition?

Urbanization reduces economic incentives for large families, leading to lower birth rates.

What defines Stage 4 of demographic transition?

Population growth is zero when birth and death rates are equal, with low birth and death rates.

What is Stage 5 in demographic transition theory?

A proposed stage where death rates exceed birth rates, leading to population decline, especially in Europe and East Asia.