Evir. Science Exam #3 Flashcards
Evolution
Changing in gene frequency within a population from 1 generation to the next
Genetic Diversity
Populations that contain genetically different individuals, which is needed for populations to evolve
Genetic Mutation
changes in DNA structure
Genetic Recombination
combination of traits arising from both parents
Natural Selection must have
genetic variation and selective pressure
Higher genetic variation means
the better chance individuals can withstand or thrive changing environmental conditions
What are the 2 main sources for genetic diversity?
Genetic mutation and genetic recombination
Natural selection must have both
genetic variation and selective pressure
Adaptations
traits favored by the environment
What is true about the evolutionary processes?
Evolution acts on existing genetic variation
Steps in Natural Selection
- Individuals with the best adaptations survive and reproduce
- The population contains more of the better-adapted individuals
- Changes in how common certain genes are
- The population has experienced evolution
Individuals are _____ for, populations ____
selected, evolve
Directional Selection
continually favors a particular extreme of the trait
Stabilizing Selection
favors the norm and selects against extremes
Disruptive Selection
favors the extremes but selects against the intermediate forms
Coevolution
when 2 species provide pressure determining which of the other’s trait is favored by natural selection
Genetic Drift
Pure chance and random mating that increases or decreases the frequency of a trait
Bottleneck Effect
Part of the population dies suddenly, leaving the survivors left to produce a new generation
Founder Effect
Small group contains only some of the original variants and becomes isolated
What is the change in gene frequency within a population called?
Evolution
Evolution can occur when random mating eliminates some genes from the population. This is called
genetic drift
Artificial Selection
selecting individuals to breed and produce a population with desired traits
Evolutionary fitness
measures the relative ability of an individual to produce viable, fertile offspring, relative to other individuals in the population
Which group of organisms have we identified the most species?
Insects
Biodiversity
the variety of life on Early, includes genetics species, and ecological diversity
What regions have the highest biodiversity?
Tropical
Nature is approximately worth
$125,000,000,000,000
Genetic Biodiversity
heritable variation among individuals of a single population
Species Biodiversity
variety of species, including richness and evenness
Ecological Biodiversity
variety within an ecosystem’s structure including many communities, habitats, niches, and trophic levels
Biodiversity Hotspots
areas that have high endemism and have lost at least 70% of their orginal habitat and contain a large number of endangered species
Examples of biodiversity hotspots
Tropical Andes and Polynesia-Micronesia
Endemic Species
Plant and animal species that only exist at 1 location on Earth
Examples of endemic species
the galapagos penguin and marine iguana
What is the world’s 36th biodiversity hotspot?
North American Coastal Plain
What percentage of endemic species lives on the hawaiian islands?
90%
What describes how isolation affects the ability of a population to adapt to changes?
Harder for a population to adapt because individuals can’t breed with other populations
What is the #1 threat to biodiversity?
Habitat Destruction
Habitat Destruction
human activities that reduce ecosystem size and unique habitats within
Fragmentation
loss part of a larger habitat, leaves patches which may be no suitable for species needing large expanses
Overharvesting
populations harvested faster than they can reproduce with crash and some species are more vulnerable than others
Invasive Species Pollution
may outcompete or displace native species, have a lack of predators, and can drive native species to extinction
Pollution
directly impacts biodiversity, organisms are sensitive to small changes, and pollutants can build up through food webs and affect many species
Climate Change
shifting weather patterns can alter or eliminate habitat
Conservation Biology
the science of preserving biodiversity
Threatened Species
species at risk of extinction
Characteristics of Endangered Species
extremely small range, require a large terrritory, living on an island, have a low reproductive success, small population size, low reproductive rates, require specialized breeding areas, specialized feeding habitats
Ex-situ Conservation
Off-site conservation tactic
Examples of Ex-situ Conservation
zoos
seed banks
captive breeding programs
In-situ Conservation
On-site conservation tactic
Examples of In-situ Conservation
landscape
habitat protection
ecosystem restoration
habitat corridors
Captive Breeding Programs
individuals carefully chosen to maximize genetic diverstiy and reared to no associate humans with food to facitlitate eventual release
Reintroduction Programs
individuals from captive breeding programs or other wild populations are reintroduced to an area with suitable habitat and protection
Seed Banks
stored seeds kept saf from habitat destruction and climate warming and is used to preserve genetic diversity adn reintroduce extinct plant species
Ecosystem conservation
focuses on propecting habitats and protects all species living there
Landscape conservation
targets a suite of species that all use vital areas of the habitat
Ecosystem restoration
protects species habitat and often benefit other species
Ecosystem restoration could include
replanting
reintroducing native species
removing invasive species
cleanup of damage or pollution
Conservation genetics
used to identify endangered populations and track illegal sale or trade of endangered species
Protected habitats
wildlife refuges and wilderness areas that are generally open to visitors and hunting/fishing but not commercially developed
Nature Reserves
closed to hunting and fishing (main goal is to protect wildlife)
Habitat Corridors
allow animals to move safely between habitat fragments
Wildlife Management
work to keep animal populations well maintained and can focus on preserving species and/or managing nuisance animals
Endangered Species Act of 1973
Mandated protection of a list of species
- Prohibits “taking” species, regardless of land ownership
- Includes capture, hunting, collection, and any conduct that might damage a species’ ability to reproduce
Convention on International Trade in Endangered Species of Wild Fauna and Flora (1973)
Regulates sale and trade of endangered or threatened species or products
Effectiveness is debatable due to the black market
Ecotourism
low impact travel to natural areas that contributes to environmental protection and respects local people
Debt-for-nature Swaps
preservation of natural areas funded by an agreement where a nation forgives part of the debt of a developing nation
Nonprofit Organizations
raises awareness, fund conservation projects, create land protections
Consumer Choices
buy products from businesses that help conservation efforts (fair trade products)
What are the 3 categories that we get from nature?
Cultural benefits, human provisions, ecosystem services and support
What are the causes of biodiversity loss?
Habitat destruction, habitat fragmentation, overharvesting, invasive species, pollution, climate change, and altered patterns of disturbance
List the 9 categories of the IUCN Red List
extinct, extinct in the wild, critically endangered, endangered, vulnerable, near threatened, least concerned data deficient, not evaluated
