3.1 Biodiversity and Conservation
What is Biodiversity?
A broad concept encompassing the total diversity of living systems, which includes the diversity of species, habitat diversity and genetic diversity.
How can biological variation arise?
mutation, sexual reproduction (random mating and fertilisation), crossing over of homologous chromosomes.
How do current rates of extinction compare to natural rates?
Much higher than predicted naturally by up to 100 times
What is the difference between species and habitat conservation
Habitat based approach (Ex situ) - improve the probability of survival of the species by taking them out of their habitat and breeding them in captivity; with the intention of re-introducing them back into the wild in the future.
Species based approach (In situ) - focuses on conserving the species in their natural habitat.
Define the difference between species-based conservation and habitat-based conservation
SBC tend to be ex situ
HBC tend to be in situ
Explain the process of natural selection.
1. Within a population of one species, there is genetic diversity, which is called variation.
2. Due to natural variation, some individuals will be fitter than others.
3. Fitter individuals have an advantage and will reproduce more successfully than individuals who are less fit.
4. The offspring of fitter individuals may inherit the genes that give that advantage.
Define speciation
It is the formation of new species when populations of a species become isolated and evolve differently from other populations.
Explain two human activities causing species loss.
Deforestation/logging/loss of habitat
Pollution/Overuse of fossil fuels contrib. to climate change
Invasive species
Etc.
Give an economic, social and ecological reason for conserving biodiversity.
Examples:
Economic: Unique species (particularly plants) may contain medicines for humans that could be sold at a profit
Social: Abundance of species is more pleasing aethetically to look at, outdoors activities are more interesting with biodiversity (i.e.scuba diving)
Ecological: We have a moral obligation to conserve life
How can natural processes in ecosystem regenerate
Rewilding
True/False: Low diversity is not found in pristine ecosystems.
False - low diversity can be present in natural, ancient and unpolluted sites (for example, in Arctic ecosystems).
What is a result of every extinction event?
Widespread species loss leading to a boom of new species adapting and evolving.
What threats do tropical biomes face?
Deforestation/logging, poaching of animals, overcultivation of land, pollution, invasive species, human activity/land disturbance, erosion, etc.
Explain the criteria for consideration when designing protected areas.
Answer should refer to at least 3 of the following: size, shape, edge effects, corridors, and proximity to potential human influence.
Define keystone species and give an example
A keystone species is an organism that has a large impact on its ecosystem relative to its abundance.
elephants, wolves, sea otters, beavers, prairie dogs, sharks, whales, hummingbirds, parrotfish, saguaro cactus, bees, and bats,
Species diversity is the product of which two variables?
It is a product of two variables: the number of species (richness) and their relative proportions (evenness).
Identify two possible causes of past extinctions
asteroid impact, volcanic activity leading to climate change, global cooling, sea level change due to glacier formation
List 3 factors that are used to classify the status of a species on the IUCN Red List.
population size, degree of specialization, distribution, reproductive potential and behaviour, geographic range and degree of fragmentation, quality of habitat, trophic level, and the probability of extinction.
Outline a specific species based approach to conservation.
I.e.
Flagship species
Keystone species
Define the tragedy of commons
The tragedy of the commons is an economic problem where the individual consumes a resource at the expense of society.
Distinguish between species, habitat, and genetic diversity.
SD: the number of different species that are represented in a given community
HD: refers to the range of different habitats in an ecosystem or biome.
GD: The range of genetic material present in a population of a species.
Give the formula for Simpson Reciprocal Index
D = 1- (Σni(ni-1) / N(N-1))
Provide an overview of a species that has a) become extinct due to human activity, b) is critically endangered, or c) whose conservation status has been improved by intervention.
Answers will vary
Evaluate the success of a named protected area.
Answers will vary
Appropriate criteria should include size, shape, edge effects, corridors and proximity.
Give 3 factors that affect ecosystem resilience.
biodiversity (species richness and redundancy), connectivity between habitats, environmental variability, presence of keystone species, ecosystem complexity (trophic levels and functional groups), disturbance regime, human impacts like land use change and pollution, climate change, and the ability of species to adapt to changing conditions