Interactions between populations

Key terms: Niche = the way an organism makes a living (its career) Examples: Habitat = where an organism lives (its address) Examples:

Businesses have niches too. Think about McDonald’s, Taco Bell, and Subway… How are their niches similar? Different?

Types of interactions: Competition: (-/-) when two species fight for the same resources. Lab: ”Hide and Go Beak” Predation: (+/-) When one species hunts and eats another.

Intraspecific Competition Occurs between members of the same species Ex: Two male birds compete for a mate Basic factor of natural selection Leads to evolution of better adaptations within a species

Interspecific competition Occurs between members of different species Often leads to extinction/Losing species dies out Can lead to greater specialization Evolve different adaptations Ex: Anole Lizard Some hunt on ground and some in trees

Competition Example: Zebras, Wildebeests and Gazelles have evolved a taste for different parts of the same plant.

Effects of competition: Crowding and stress Symptoms include: Aggression Decrease in parental care Decrease fertility Decrease in resistance to disease Can lead to decrease in population size

PREDATION:

Predation example: Snake can detach its jaw to fit a mouse inside.

What type of interaction? Predation

Predator-Prey Interactions Make a T chart… Survival Adaptations in Prey …in Predators

Some Adaptations in Predators Speed Weapons Stingers Venom Sensors Agility Camouflage Intelligence

Some Adaptations in Prey Speed Weapons Poison Sensors Camouflage Deceptive markings Warning coloration Mimic a harmful species Mimicry ????

Which adaptation? Camouflage: canyon tree frog

Which adaptation? Deceptive markings: False eyespots

Poison Arrow Frog Warning coloration Which adaptation?

Hawk moth larva (non-venomous Insect larva) Green parrot snake (venomous) Mimicry

Another example of Mimicry Cuckoo bee (tastes bad) Yellow jacket (tastes bad) Two inedible species mimic each other

Which adaptation? Deceptive coloration What does this look like to a bird?

Deceptive Coloration Deceptive coloration

Parasitism: (+/-) When one species uses and harms another species, but keeps it alive. Mutualism: (+/+) When both species benefit from the interaction. Commensualism: (+/0) One species benefits and the other is unaffected. Other Interactions :

Both ants and acacia trees benefit. What type of interaction? Mutualism

Egret gets a perch and a free ride. Water buffalo is unharmed. What type? Commensalism

The guinea worm is coiled under the skin of an 18 year old man. This is not good for the man. What type of interaction? parasitism

The green color is from photosynthetic algae that live in the tissue of this anemone. What type of interaction? Mutualism

What type of interaction? Commensalism

SYMBIOSIS Symbiosis Lab The word symbiosis was first defined as “unlike organisms living together”. The relationship between these two unlike organisms can be positive, negative or neutral. There are three types of symbiotic relationships- mutualism, commensalism and parasitism.