Chapter 5 Evolution Flashcards
Bottleneck Effect
Reduction of genetic diversity due to population decrease from CATASTROPHIC EVENT
Founder Effect
Reduction of genetic diversity due to population decrease from MIGRATION OF A FEW MEMBERS OF THE POPULATION
Cons of lower diversity
- Less able to adapt to future environmental changes
- Can lead to decline and extinction
- Increased risk of disease/low fertility
Artificial Selection
Process of selection conducted under HUMAN instruction
- desirable traits bred into next generations
- Bad scenarios: Bacteria becoming resistant to antibiotics
Genetic change/traits must exist _____________ environmental change
BEFORE
Allopatric Speciation
Populations are physically separated and evolve into 2 different species
Geographic Isolation
Certain groups of the same population become physically isolated for a long period of time
Reproductive Isolation
Two populations change so much that they can no longer produce viable offspring with each other
(No interbreeding)
____________ isolation leads to ____________ isolation
Geographic leads to Reproductive
Genetically Modified Organism (GMO)
Copying genes from one species with a desirable trait and inserting it into another
Extinction
The disappearance of a species from Earth
______ mass extinctions in history
5
Worst mass extinction
Permian Extinction
(90% of life destroyed)
Mass Extinction
25% of species lost in “short” amount of time (thousands of years)
Endemic species
Species that only exist in a certain location
- very susceptible to extinction
- usually have small populations
ex. Kangaroos
Human causes of mass extinction
Habitat destruction
Hunting
Over harvesting
Introduction of invasion species
Range of tolerance
Abiotic conditions a species can TOLERATE
Fundamental Niche
Abiotic conditions where a species can grow, survive, and reproduce
(Perfect conditions)
Realized Niche
Abiotic/Biotic range of conditions under which a species actually lives
Distribution
Areas of the world where a species live
Niche Specialist
Narrow niche
Specific needs
LIMITED COMPETITION
Vulnerable to changing conditions
Niche Generalist
Broad Niche
Wide array of habitats/resources
Can better adapt to changing conditions
Niche overlap
Competition
Native species
Evolved in area, been there for generations
Nonnative species
Alien or exotic species
Good nonnative species
Cattle
Chickens
Crops
Invasive species
Takes over environment, spreads rapidly, sometimes no natural predators
ex. Zebra Mussels
Indicator Species
Provide early warning of damage to an ecosystem (change in environment)
ex. Frogs, Birds, Butterflies, Trout
Keystone Species
Play large roles in types and abundance of other species in the ecosystem
- pollinators
- top predators (sea otters in kelp forests)
They have a strong and wide-reaching impact
Removal of the species has a ripple effect
Foundation Species
Create/enhance habitat which benefits others
ex. Beavers create wetlands with dams
Tropic cascade
Predators at high tropic levels indirectly affect populations at low trophies levels
- keeps species at intermediate tropic levels in check
- keeps population in check
ex. Loss of wolves = deer takeover
Macro evolution (speciation)
Bigger changes that lead to the development of new species over time
Micro evolution
Small changes over time
Types of biodiversity
Species
Genetic
Ecological
Functional
Species Richness
Number of species in a give area
Species Eveness
Relative proportion of individuals within the different species in a given area
Intraspscific Competition
Members of the same species interact/compete for limited resources
ex. Competing for mates
Interspecific Competition
Members of 2+ species interact/compete for limited resources
Resource Partitioning
Species use different resources or use shared resources in different ways
ex. One species active at night and other active during the day
Predation
A member of one species feeds directly on another living species (kills and eats)
Coevolution
Predators and prey interact long enough that a change in the gene pool of one leads to a change in the other
Herbivory
Animals feed on the tissue of plants
Mutualism
Interaction between 2 species in which both benefit
ex. Tiny bird cleaning crocodile teeth by eating food off of them
Parasitism
One organism feeds on another causing harm to the host
Commensalism
Interaction between 2 species that benefits one and causes no harm to the other
ex. Bird building a nest in a tree
