Lecture 11: Ecology

Question 1

Community Ecology

Answer 1

Study of the interactions between species in communities.
Includes the study of the distribution, structure, abundance, demography and interactions between coexisting populations.
What constitutes a community and size of its territory is open to debate.

Question 2

Interactions between Species

Answer 2

Different species within a community can interact with each other.
These interactions classified by ecologists: Competition
Predation
Symbiosis: parasitism, mutualism & commensalism
Facilitation.

Question 3

Interactions between Species: Competition

Answer 3

Interspecific competition: When different species compete with each other over finite resources.
The species can compete for food, habitat, sunlight etc.
If 2 species occupy same niche, one will die.

Question 4

Ecological Niche

Answer 4

Ecological Niche: sum of a species’ use of the biotic and abiotic factors in its environment.
Species way of life.
Analogous to a species’ job.

Question 5

Ecological Niche Modeling

Answer 5

Hard to determine where a species is and where it likes to live.
Combine the observations of a species with abiotic date (temp, altitude, rainfall)
Use an algorithm to build a model of the tolerances of the species and fine its niche.

Question 6

Organisms Occupying the Same Niche Can Evolve the Same Traits

Answer 6

Convergent Evolution

Question 7

Predation

Answer 7

When one species eats another species.
Predator doesn’t always kill the prey or always consume the entire living organism.
Inclues Herbivory: eating of plants and algae.
Overlaps with parasitism in the case of parasitoids.
Predation and predator defense drive evolution in many organisms.

Question 8

Predator Adaptations

Answer 8

Teeth, claws, speed, patience, venom, smell, vision, echolocation, camouflage, social behavior, etc…

Question 9

Anti- Predation Adaptations

Answer 9

Mimicry, camouflage, poison, detachable tails, speed, smell, vision, social behavior, thorns…

Question 10

Evolutionary Arms Race

Answer 10

It’s a fight between competing sets of co-evolving organisms or genes that develop adaptations and counter- adaptations against each other.
The war can be fought between predator and prey or parasite and host.

Question 11

Co-Evolution

Answer 11

Joint evolution of two interacting species, each in response to selection imposed by the other.
Can occur at the species level or the molecular level.
Occur in predator/ prey, host/ parasite, and mutualistic relationship.
Darwin wrote about it.

Question 12

Warning Coloration

Answer 12

Anti-predator adaptation.
Advertising that the potential prey tastes bad or is poisonous.
Coloration can be mimicked by other organisms.

Question 13

Mimicry, Camouflage

Answer 13

Mimicry: Similarity of one species to another conferring an evolutionary advantage to one or both species.

Camouflage: When a species resembles its surroundings
Can be visual, aural or olfactory.

Question 14

Interactions between Species: Symbiosis

Answer 14

An ecological relationship between two different species that live together in direct contact.

Can be bad for one of the species.
Types of Symbiosis: Parasitism, Mutualism and Commensalism

Question 15

Symbiosis: Parasitism

Answer 15

Symbiotic relationship where one organism benefits at the expense of other.
Parasite lives either on (ectoparasite) or inside (endoparasite) of the host and feeds on cell components, tissues or body fluids.
Parasites don’t usually kill the host as this would deprive them of a host.

Question 16

Symbiosis: Parasitism- Parasitoids

Answer 16

Live attached to or within a single host organism in a parasitic relationship, but eventually sterilizes or kills, and sometimes consumes the host.

Insects are most famously parasitoids, but other arthropods, prokaryotes, vertebrates and even plants can be parasitoids.

Question 17

Parasitoid Wasps

Answer 17

Adult, Adult ovipositing egg into fly pupa, egg inside fly pupa, larva, pupa, adult emerging. = Adult.

Question 18

Symbiosis: Mutualism

Answer 18

Symbiotic relationship where both organism benefit.

Question 19

Symbiosis: Mutualism: Mycorrhiza

Answer 19

Mycorrhiza is a mutualistic association between a fungus and the roots of a vascular plant.
95% of plants have mycorrhiza.
Sometimes these associations are pathogenic

Question 20

Symbiosis: Commensalism

Answer 20

A symbiotic relationship where one organism benefits and the other is neither harmed nor helped.
Some relationships appear commensal but are not when viewed more carefully or are not commensal for all members of the population.

Question 21

Symbiosis: Commensalism Example?

Answer 21

Remora fish hitchhike on large organisms.
Sometimes they clean the larger organisms’ teeth and eat their poop.
Sharks have observed eating remoras attempting to attach onto them.

Question 22

Demodex

Answer 22

Mite that lives in human hair follicles.
Not everybody has them but most do.
Considered to be a commensal skin organism.
Can cause skin problem in some people (acne)
They eat your skin cells and oil.They mate, lay eggs, defecate and die in hair follicles. Crawl out at night.

Question 23

Lichens

Answer 23

Symbiosis between fungi and algae or bacteria.

Associations can be mutualistic, commensal or parasitic depending on species

Question 24

Endosymbiotic Theory

Answer 24

Endo= with, Sym= together, Biosis= living.
Several eukaryotic organelles were originally free living microorganisms.
They now live with Eukaryotes in symbiotic relationship.
Secondary endosymbiosis have occurred.

Question 25

Facilitation

Answer 25

An interaction where one species has a positive effect on the survival of another species without the intimate association of a symbiosis.

Some plants may make it easier for other plants to grow in the area.