EV Bio Spring Final

What is the difference between the exponential and logistic growth models, their assumptions, and their outcomes?

Exponential growth assumes unlimited resources and causes rapid population growth. Logistic growth assumes resources become limited, so population growth slows as it approaches carrying capacity.

What is the equation for the exponential growth model?

DN/Dt=rN

Which population growth model produces a j-shaped curve?

The exponential growth model.

In what situations in nature would we expect population growth to approximate exponential growth?

When resources are unlimited, competition is low, or a species enters a new environment.

What is the equation for the logistic growth model?

dN/dt=rN (I-N/K)

Which population growth model produces an s-shaped curve?

The logistic growth model.

What is carrying capacity?

Carrying capacity is the maximum population size an environment can support long-term.

What happens to a population and carrying capacity if carrying capacity is exceeded?

Resources become depleted, causing population decline, starvation, disease, or crashes

What is the difference between density independent and density dependent limiting factors?

Density dependent factors become stronger as population size increases, while density independent factors affect populations regardless of size.

What are some examples of each?

Density dependent: disease, competition, predation.
Density independent: hurricanes, fires, droughts.

What are the different types of competition?

Intraspecific competition (within the same species) and interspecific competition (between different species).

What is their impact on each of the interacting individuals?

Both individuals are negatively affected because they compete for limited resources

What are the different types of exploitation we discussed?

Predation, herbivory, parasitism, and parasitoidism.

What is their impact on each of the interacting individuals?

One organism benefits while the other is harmed.

What is a refuge?

A refuge is a place where prey can avoid predators.

How do refuges affect predator-prey relationships?

They help prey survive and prevent predators from eliminating prey populations completely.

What is mutualism?

A relationship where both species benefit.

What are its effects on the interacting individuals? What are some examples of mutualism that we discussed?

Both organisms benefit. Examples include bees pollinating flowers and clownfish living with sea anemones.

What is a niche?

A niche is the role a species plays in its environment, including how it survives and interacts with other species.

How do each of the different types of species interactions we discussed (competition, exploitation, mutualism) impact a species’ realized niche?

Competition usually reduces a species’ realized niche, exploitation can limit where species survive, and mutualism can expand survival opportunities.

What are the predictions of the theory of island biogeography?

Larger islands and islands closer to the mainland will have more species.

What causes the outcomes that the theory predicts?

Higher immigration rates and lower extinction rates.

What is a barrier to dispersal?

Something that prevents species from moving into new areas.

What are some examples of barriers to dispersal?

Oceans, mountains, deserts, and climate differences.

What are the different types of dispersal abilities that could help a species cross a barrier to dispersal?

Flying, swimming, floating, or being carried by wind or animals.

What is the difference between an oceanic island and landbridge island?

Oceanic islands form in oceans and were never connected to continents. Landbridge islands were once connected to the mainland.

When a landbridge island becomes cut off from the mainland, what are the consequences for species?

Species can become isolated and evolve separately, leading to speciation or extinction.

What is a vicariant event? (See speciation lesson

An event that separates populations geographically.

How can a vicariant event result in speciation?

Separated populations evolve independently until they become different species.

What is an endemic species?

A species that can only be found in one location

Why would some islands have higher percentages of endemic species than others?

Long isolation allows species to evolve separately over time.

What does fossil and genetic evidence tell us about the evolution of humans?

Humans evolved from earlier primates and share common ancestors with other animals.

Review lesson 2 on the Linnaean Classification System. Make sure you know how to interpret a phylogeny.

Phylogenies show evolutionary relationships and common ancestry between species.

When did anatomically modern humans (Homo sapiens) originate?

300,000 ya

How large is the human population predicted to be by 2050? By 2100?

About 9.7 billion by 2050 and over 10 billion by 2100.

What is an ecological footprint?

The amount of resources and land humans use to support their lifestyle.

What is biocapacity?

The Earth’s ability to regenerate resources and absorb waste

How can the concepts of ecological footprint and biocapacity be used to estimate the carrying capacity for humans on planet earth?

They compare how much humans use versus how much Earth can sustainably provide.

What does the current analysis of these concepts indicate about humans on planet earth?

Humans are using resources faster than Earth can replace them.

What is a functional extinction?

When a species becomes too rare to play its ecological role.

What is the Allee Effect?

Small populations struggle to survive and reproduce.

What human activities are damaging coral reefs?

Climate change, pollution, overfishing, and ocean acidification.

Where is the only place in the world that lemurs live?

Madagascar

Why should we be concerned that wild populations of species are declining?

Population declines weaken ecosystems and increase extinction risk.

What can be done to reduce the global decline in biodiversity?

Protect habitats, reduce pollution, lower greenhouse gas emissions, and conserve endangered species.

Make sure to review how evolution, speciation, and adaptive radiation occur.

Evolution occurs through natural selection, speciation occurs when populations become isolated, and adaptive radiation happens when species rapidly diversify into new niches

Explain how adaptive radiation results in the re-diversification of species following a mass extinction event.

After extinctions create empty niches, surviving species evolve into many new forms.

What were the characteristics of the end-Permian and end-Cretaceous extinctions?

The end-Permian was the largest extinction event. The end-Cretaceous killed the dinosaurs.

What caused each?

End-Permian: volcanic eruptions and climate change.
End-Cretaceous: asteroid impact and environmental changes.

What were the consequences of each?

Massive biodiversity loss and ecosystem collapse.

How did biodiversity recover following each?

Through evolution and adaptive radiation over millions of years.

What are the major types of fossil fuels?

Coal, oil, and natural gas.

What are the major human generated greenhouse gasses?

Carbon dioxide, methane, nitrous oxide, and fluorinated gases.

How have their concentrations changed over time?

They have increased rapidly since the Industrial Revolution.

Where in the environment has CO2 released by humans accumulated?

In the atmosphere, oceans, and plants.

Where in the environment has heat generated by these greenhouse gasses accumulated?

Mostly in the oceans.

How does CO2 damage coral reefs?

It causes ocean acidification, making it harder for corals to build skeletons.

What is the mode likely amount of warming between 1850 and 2100 according to the IPCC?

About 2–4°C of warming.

What effects does climate change have on the distribution and processes of natural systems?

It changes biomes, species distributions, weather patterns, productivity, and decomposition rates.

What is intrinsic value?

The idea that nature has value simply because it exists.

What is the difference between anthropocentrism and biocentrism?

Anthropocentrism values nature based on benefits to humans, while biocentrism believes all living things have value

What can be done to reduce the impacts humans are having on natural systems?

Use renewable energy, conserve habitats, reduce pollution and waste, protect biodiversity, and live more sustainably.