Lecture 13: Ecology

Question 1

ecology

Answer 1

study of…

• how organisms interact with each other and with their environments
• distribution and abundance of species
• structure and function of ecosystems

Question 2

Who proposed endosymbiotic theory for origin of mitochondrion?

Answer 2

Lynn Margulis proposed this theory is 1967 suggesting that mitochondria are a product of ancient symbiosis. Host cell engulfed bacteria, bacteria become eukaryotic cells.

Question 3

How many species of eukaryotes are there?

Answer 3

8.7 million. This number doesn’t include bacteria or archea, there are simply too many to count. Biodiversity is not equally distributed across tree of life.

Question 4

Model organisms vs Non model organisms

Answer 4

lab mice, fruit fly, some plants vs literally everything else

Question 5

Questions evolutionary and ecological biology ask…

Answer 5

WHY questions
Why do eukaryotic cells have mitochondria? Why don’t prokaryotic cells have mitochondria?
Why do mitochondria have their own genome?

Question 6

Evolution is a conjunction of…?

Answer 6

ecology and genetics

Question 7

population

Answer 7

all individuals of the same species in one place at one time

Question 8

community

Answer 8

all the species living together in one place at one time

Question 9

ecosystem

Answer 9

all species plus the non-living environment

Question 10

Determining factors for where species live…

Answer 10

dispersal –> abiotic conditions (climate and nutrients) –> species interactions (competition, predation, mutualism)

ex. the scarlet macaw can handle higher temperatures way better than the great Inca finch thus they are dispersed in different areas

Question 11

Inexhaustible vs exhaustible conditions

Answer 11

inexhaustible conditions are factors like climate (salinity, precipitation) while exhaustible conditions can be used up (food, nutrients, space).

Question 12

What are the areas of performance on the bell curve of intensity of conditions vs. performance of species?

Answer 12

Conditions exist in GRADIENTS. The peak of this curve corresponds to reproduction (R), one standard deviation out is individual growth (G), another SD out is individual survival (S). Past S are lethal zones where organisms die (past range of tolerance), ex. Mt. Everest above 8000m where O2 levels are 1/3 of what they are at sea level.

Question 13

The sixth extinction

Answer 13

result of human activities, 32% of known vertebrate species (8851 of 27600) are decreasing in population size of range.

Question 14

Example of a species that can live almost anywhere and one that can live essentially nowhere

Answer 14

Mountain lion populations span continents (Africa, NA) while the American Pika exists only in one part of western NA.

Question 15

What is eBird

Answer 15

largest biodiversity-related citizen project in the world. People submit bird observations and locations.

Question 16

How is species distribution also relevant to disease control?

Answer 16

Infectious diseases are technically species. We want to understand the patterns of their dispersal to combat it.