Unit 3 Flashcards
Genetic Diversity
A measure of the genetic variation among individuals in a population
Species diversity
The number of species in a region or in a particular ecosystem
Habitat Diversity
The variation/variety of habitats that exist in a given ecosytem
Ecosystem Diversity
The Variety of ecosystems that exist in a given region
Population Bottleneck
When a large population declines in number, the amount of genetic diversity is carried by the surviving individuals is greatly reduced
Species Richness
The number of different species in a given area
Species evenness
The relative proportion of individuals within a different species in a given area
What are current challenges to estimate the number of living species on Earth?
- Active during night hours
- Found in inaccessible areas
- Too small to be found with the naked eye
-Range and numbers are too great to quantify
Ecosystem Services
The process by which life-supporting resources such as clean water, timber, fisheries, and agricultural crops are produced
What are the 4 ecological services?
Provisional, regulating, supporting, and cultural
Provisional
Are considered goods humans can use directly
EX: Furs, trees, natural pharmaceuticals
Regulating
Services that maintain environmental conditions
EX: Removal of carbon dioxide by plants, flood controls, temperate control in forested areas
Supporting
Services that would be costly for humans to generate
EX: Pollination, pathogen removal/filtrate
Cultural
Services that provide intrinsic/aestetic benefits for certain groups of people
Ex: Natural bueaty draws visitors or religious groups, septic economic value can be attached to ecosytem services
Human activities
Food production, fish/shelfuish production, water availability, pollination services
/Island Biogeography
The study of how species are distributed and interacting on islands?
Larger Islands= more species b/c of resource availability
Islands closer to mainland = Morespeices diversity
Species area curve
A description of how the number of species on an island increase with the area of the island
Why is it that species that evolve on islands tend to be specialists
- Some species may lack predatation
- Food sources may be specialized to the island
- Adaptions can occur rapidly
What are thginbgs you need to know about Island Biography
- Need of producers will affect ecological efficency
- Distance to mainland tends to be a major affect due to coloinazation frequency and ease
- Islands of similar size, but closer to proximity to mainland will have higher species diversity
- Smaller islands can’t support large numbers of predators, so producers wont last
What is limited resources and why does it happen
- Colonization slows, extinsction rises
B/c of larger population in species
Ecological Tolerance
The suite of a optic conditions under which a species survive, grow, and reproduce (Fundamental niche)
Fundamental Niche
Entire way of life for particular organism
Realized niche
The range of abiotic and biotic conditions under which a species actually lives
Geographic Range
Areas of the world in which a species lives
- Bitoic and Abotic conditions affect t this
- Habitats have changed and species have been forced to adapt
How many mass extinctions have there been?
5
- Earth is undergoing its 6th mass extinction
Mass Extinction
Short period of time where 65-95% of all species became extinct
Periodic Desruption
Occurring at regular intervals (night and day)
Episodic Disruptions
Somewhat regularly (Drought and rain intervals)
Random Disruptions
no regular pattern (Natural Disatsters)
Resistance
If a species is largely unaffected by disruption
Resilience
If a species is affected by disruption, the rate it takes to return to its original states
If ecosytem is more diverse is resistance and resilience higher or lower
More resilient and resistant
What are methods to measure change?
- species composition
-Gas bubbles in ancient ice
-Measuribg melt of ice sheet
Intermediate Distyurbance hypothesis
Hypothesis that ecosytems experiencing intermideate levels of disturbance will favor higher level of diversity of species then those with high or low disturbance levels
Intermediate Distyurbance hypothesis
Hypothesis that ecosytems experiencing intermideate levels of disturbance will favor higher level of diversity of species then those with high or low disturbance
Evolution.
A change in genetic composition of a population over time
Micro evolution
Evolution at the population level
Macro evolution
Evolution that gives rise to new species, genera, families, classes, or phyla
Evolution by Artifical Selcetion
the progress in which humans can determine which individual to breed typically with a preconceived set of traits in mind
Evolution by Natural selection
The process in which the environment determine which indiduals survive and reproduce
Fitness
An individuals a ability to survive and reproduce
Adaption
A trait that improves an individuals fitness
Evolution by random processes
The process that alter the genetic composition of a population over time, but not related to differences of fitness
What were Darwin’s key ideas about natural selection
- Individuals produce excess of offspring
- Not all offspring survive
- Different traits get passed from parent to offspring
- Those that have the ability to survive and reproduce pass on their traits
Mutations
Changes to the genetic variation of a population
Gene flow
Individuals moving from one population to another
Genetic Drift
Simple change in genes over time due to random mating
Bottleneck Effect
A reduction in the size of a populations genetic variation
Founders affect
A few individuals begin a new population with genotypes not representative of the larger group
Allopathic Speciation
A geographic separation in a population, leading to new species (Once too long apart, they develop diffract alleles and genes)
Sympathetic Speciation
Genetic isolation without geographic separation in a population, leading to new species
Ecological Succession
The predictable replacement of one group of species by another group of species over time
Primary Succession
Ecological succession occurring on surfaces with bare rock and no soil
Pioneer species
In primary succession, species that can survive with little or no soil
Secondary Succession
The succession of plant life that occurs in areas that have been disturbed but have not lost their soil
Climax Commuity
Historically described as the final stage of succession
How does succession begin/
Increase in Species richness, biomass, and productivity
Indicator Species
Those which canan demonstrate characteristics of an ecosytem
EX: Lichens
Key stone species
An organism that is a rock and necceistity of an ecosytem
Convergent Evolution
Two species developing similar traits due to their habitants and co existence
Pyroclastic flows
hot river and ash that flow down a side of the river
Example of what occurs before primary succession
Salizanation
Soil become saline
