chapter 5 Flashcards
Genetic diversity vs species diversity vs ecosystem diversity distinctions
Genetic diversity focuses on genetic differences within a species.
Species diversity is about the variety of species in an area.
Ecosystem diversity deals with the variety of different ecosystems in a region.
Describe what is meant by background extinction rate. What is the background extinction rate? How does the background extinction rate compare to the current number of species estimated to be going extinct each year?
The background extinction rate is the rate at which species go extinct naturally without any external interference
The BER is supposed to be 1-5 species per million per year. Actual rate is somewhere between 100-1000 times that
Explain how habitat loss affects specialist species compared to generalist species. Is it better to protect habitats or to try to save individual species? Explain your reasoning
Habitat loss is more devastating to specialist species who need highly specific environments to thrive. Conserving habitats is better (more cost effective, protects multiple species at once, prevents future extinctions, helps preserve the essential functions of ecosystems)
Invasive species
Nonnative species that harm their new habitat
Characteristics:
- Rapid reproduction
- Lack of native predators or competitors
- Damages biodiversity/functioning of new ecosystem
Examples:
- English Ivy
- Zebra mussel
- Kudzu (vine that ate the south)
Indicator species
Species that can indicate the health of an ecosystem via their presence/absence/health
Characteristics
- sensitive to environmental change
- Can indicate environmental health
- Often used in conservation efforts
Examples
- Lichens sensitive to air pollution
- Amphibians sensitive to changes in water quality and air quality - multipurpose indicator
- Mayfly Nymphs - Their presence in rivers indicates good water quality, while their absence suggests pollution.
Foundation species
Species that play pivotal roles in establishing/shaping ecosystems by creating habitats
Characteristics
- They have a significant impact on ecosystem structure and biodiversity.
- Provide essential resources (e.g., food, shelter) for other species.
- Often serve as habitat providers or primary producers in ecosystems.
Examples:
- Coral
- Oak trees
- Beavers (make dams)
Endangered species
Species that have a very high risk of going extinct
Characteristics
- Very small populations in the wild
- Limited geographic range/population size
- Often subject to very intense conservation efforts
Examples
- tiger
- blue whale
- sea otter
Threatened species
Species that will likely become endangered but are not quite endangered
Characteristics
- declining population but not quite critically low yet
- conservation efforts needed to prevent future decline
- often struggle with similar things to endangered species (habitat loss, overexploitation, etc)
Examples:
- snow leapord
- african elephant
- bald eagle
Endemic species
Species only found in certain parts of the world
Characteristics
- limited geographic range
- very vulnerable to extinction due to limited geographic range
- adapted/dependent on unique habitats
Examples:
- kakapo
- galapagos turtle
- redwoods
Why do many islands possess endemic and specialist species? How would invasive species threaten the survival of endemic species on islands?
Due to geographic isolation preventing migration, lack of competitors native to the island
Invasive species can create unforeseen competition for resources/outcompete native endemic species
Introduce diseases, predation, etc
Species richness vs species evenness
Richness - raw # of species, not regarding how many of each
Evenness - balance between species
What is a phylogenetic tree? What do these diagrams help us understand? Draw an example of a phylogenetic tree.
Evolutionary tree, demonstrates how diff species evolved from each other
Uses
- helps us understand common ancestors, speciation, help with comparitive biology to identify potential similarities
Describe what is meant by the “bottleneck effect” (population bottleneck). What effect does a population bottleneck have on the genetic diversity of a species? Explain with an example.
Sharp reduction in population size due to an environmental or human-caused incident, associated with steep reduction in genetic diversity and increased risk of inbreeding
Cheetahs are genetically super similar, have high rates of infertility and other issues associated w low genetic diversity
What is the founder effect + an example explaining impact on genetic diversity
The founder effect refers to a loss of genetic variation that occurs when a small group of individuals establishes a new population in an isolated location.
For ex –
The amish have a really high rate of a particular kind of dwarfism
What defines a mass extinction? According to the fossil record, how mass extinctions have previously occurred on Earth? Make a list of the 5 mass extinctions, state when each occurred and what scientists think caused the extinctions.
3 things that define a mass extinction
- widespread loss of species
- global impact
- impact across diff groups of animals
I’m giving up on remembering the mass extinctions unfortunately we will be cutting our losses
What data suggests that the sixth mass extinction is currently taking place? What is causing the sixth mass extinction?
Data:
- Abormally high extinction rate compared to backg
- widespread declines in biodiversity
- observable impacts on ecosystems and species.
Primarily caused by various human activities (overexploitation, overfishing/hunting, habitat destruction, urbanization, wtv else)
What is causing global declines in the genetic diversity of domesticated species (species grown for food, crops, livestock, etc.)? What are people doing in order to try to preserve genetic diversity in domestic species?
Causes:
- monoculture farming, growing only one thing in one large area reduces genetic diversity
- selective breeding for desirable traits reduces genetic diversity
- pesticide and herbiside usage leads to the survival of only a few genetically similar varieties that r resistant
- globalization has led to survival of the fittest
solutions:
- crossbreeding to create new varieties out of existing ones
- diversifying farmland by planting may diverse crops together
- legal protections regulating GMOs
Define the IUCN (International Union for Conservation of Nature) categories: extinct, endangered, threatened, near-threatened, and least-concern species.
Extinct: A species is considered extinct when there is no reasonable doubt that the last individual has died.
Endangered: Very likely to go extinct soon in the wild
Threatened: Not quite endangered, but could become endangered if nothing changes
Near threatened: could become threatened in the near future
Least concern: healthy, abundant populations
For each of the following groups of organisms, list the percentage of each that are considered threatened, near-threatened, and least concern.
Conifers; birds; reptiles; mammals; amphibians; and fish
Which category of organisms has the most threatened species and is experiencing the greatest global declines? Why would this group have the most vulnerable number of species?
Among the groups listed, amphibians have the highest percentage of species that are considered threatened (41%). They are experiencing the greatest global declines among these groups.
Reasons why
- permeable skin, sensitivity to external conditions
- habitat loss (impacted by both aquatic and terrestrial)
- highly suspeptible to disease and polllution
Provisioning
Getting food/resources from ecosystems (like food via fishing/gathering and fresh water from lakes)
Disrupted by deforestation, reducing the output of forests and water pollution
Regulating
Climate regulation (bodies of water keep temp steadier) and pollination.
Pesticide usage harms pollinators and excess carbon emissions prevent bodies of water from effectively regulating temps
Cultural
Non-material benefits like hiking trails and aesthetic value
Urbanization and pollution disrupt natural beauty
Supporting
Processes that support other ecosystem services like soil formation and nutrient cycling (harmed by industrial agricultural practices which disrupt natural decomposers/soil formation)
IUCN
Establishes red list to identify urgent need for conservation efforts, spearheads some field conservation programs
CITES
International treaty focused on regulating international trade of wildlife and ensuring that it does not cause harm to them. Allows for certain animals to be classified as protected and creates a system for global enforcement of wildlife trafficking laws
Convention on Biological Diversity (CBD)
International treaty attempting to preserve biodiversity by setting national goals and action plans and promoting sustainable usage
Lacey Act
U.S. law that prohibits trafficking in illegal wildlife, fish, and plants.
The Marine Mammal Protection Act
The MMPA is a U.S. law that prohibits the “take” (hunting, capturing, or killing) of marine mammals in U.S. waters and by U.S. citizens, with limited exceptions.
Endangered Species Act (ESA)
U.S. law that provides for the protection of species at risk of extinction and the preservation of their habitats. Protects endangered species and their habitats. Creates recovery plans
Debt for Nature
Program where a portion of a country’s foreign debt is forgiven in exchange for the country’s commitment to invest in conservation projects and biodiversity protection. Creates a financial incentive to meet climate goals and creates funding for conservation efforts elsewhere
When protecting areas of land or water as nature preserves, describe how the size, shape, and connectedness of the protected area are important factors to consider.
Size - larger areas can support more species/individuals however due to land-use restrictions and funding, it can be harder to protect large areas. Also larger area = more diversity = reduced extinction risks
Shape - more compact, less fragmented territories result in reduced edge effect, allowing for more undisturbed space in the middle of the reserve. sometimes irregular shapes are necessary due to geographic features
Connectedness - corridors allow gene flow and boost resiliance to climate change/other external changes. Human activity (roads, etc) might necessitate fragmentation.
What is “edge habitat”? Why does the amount of edge habitat matter when planning protected habitats?
Edge habits have diff species than interior (ones that thrive in disturbed areas) and usually are not good for internal species which require more stability/space. Edge habits are more vulnerable to external changes and invasive species
Describe biosphere reserves. Which three zones should be considered when planning biosphere reserves? Describe the importance of these zones.
They maintain biodiversity while fostering sustainable livelihoods for local communities.
Biosphere reserves are meant to act as living laboratories, where scientists can study ecosystems, human impact on the environment, and sustainable resource management practices.
Three zones – core zone, strictly for conservation and research efforts, buffer zone with reduced human activity that supports ecosystem development and transition zone with more human activity sustainable land-use practices, integrates conservation with community development, and generates economic benefits.
