Lecture 13: What is ecology and why does it matter

Question 1

What is ecology

Answer 1

the science of:
* How organisms interact with each other and with their environment
* The word ‘ecology’ comes from the Greek word oikos (home/place to live)
* The distribution and abundance of species
* The structure and function of ecosystems
* In a nutshell, the science of biodiversity

Question 2

population

Answer 2

all the individuals of the same species in one place at one time (all the zebras in a savanna)

Question 3

community

Answer 3

all the species living together in one place at one time (all the zebras, giraffes, elephants, plants, insects, etc., in a savanna)

Question 4

ecosystem

Answer 4

all the species plus the non-living environment (the entire savanna)

Question 5

What determines where species live?

Answer 5

Dispersal

Abiotic conditions
* Climate
* Nutrients

Species interactions
* Competition
* Predation
* Mutualism

Question 6

What limits a species’ range?

Answer 6

• Dispersal
• Climatic or other inexhaustible conditions, e.g., temperature, salinity, etc.
• Food or other exhaustible resources, e.g., nutrients, space, etc.
• Species interactions, e.g., competition, predation, or mutualism
• These factors vary across space and time; we envision gradients of conditions
• Organisms perform best at certain portions of a gradient

Question 7

What is The sixth extinction

Answer 7

• Ongoing mass extinction, mainly as a result of human activities
• 32% of known vertebrates species (8,851 out of 27,600 species) are decreasing in population size or range (Ceballos et al. 2015, PNAS)
• You will be reading a recent paper on bird declines in North America later in the course (Rosenberg et al. 2019, Science)