Download - Unit 11 Exam Review
Unit 11 Exam Review
• Conservation Biology – – Conservation may be defined as the
management and sustainable use of the natural environment and natural resources for ethical reasons and the benefit of humanity.
• Human history & habitat destruction – – Unsustainable land use practices have been
around for thousands of years.
• Preservationists –
• Conservationists –
• Three Guiding Principles of Conservation Biology:– Evolutionary Change – • Consequently the goal of this principle is to allow
populations to change in response to environmental changes through adaptations.
– Dynamic Ecology – • The ecological world is seen as dynamic; largely
functioning through non-equilibrium principles.– Human Change – • Humans are participants within both na-tural and
perturbed ecosystems and their presence within ecosystems needs to be recognized and accounted for.
• Conservation Biology & Economics –
• Three objectives of the World Conservation Strategy – The maintenance of the ecological processes that
life depends on; The sustainable use of ecosystems
and their component species; The conservation of genetic diversity.
• Conservation Biology, Standards of Living, and Human population – Human expectations of a decent standard of
living include food, shelter, water, space, education and a freedom of choice.
The problem of human pressure on natural resources is further complicated by the global problem of population growth.
• Conservation & Self-Sufficiency – – Many countries that, a few years ago, were self-
sufficient in food, now have to import food. They tend to make extensive rather than
intensive use of the land. Landless people migrate to unoccupied public
lands (i.e. natural vegetation). – Government indifference (as shown by their
priorities) is one of the main causes of hunger.
• Unnecessary Wastefulness & its Consequences – Wastefulness is not the confined to the poor.
Wealthy societies are even more wasteful. In many developing countries, large tracts of
land are wastefully cleared to provide exports to these wealthy countries.
The fishing industries of the wealthy nations have collapsed. The fishing industries of de-veloping countries have also collapsed due to local exploitation for export to the wealthy nations or their inability to police fishing rights leased to wealthy countries.
Overexploitation can become habitat destruction and cause species extinction.
The loss of tropical rainforests is serious. Other ecosystems under threat are wetlands, coastal areas, arid and semi-arid rangelands.
• Genetic Diversity –
• Species Diversity –
• Ecosystem Diversity –
• Approximate number of known species on the planet –
• Reasons for the above-mentioned uncertainty:
• Adaptive radiation –
• Latitudinal Gradient –
• Extinction vs. Extirpation –
• Background Extinction –
• Number of Mass Extinctions –
• Habitat Alteration –
• Invasive Species –
• Pollution –
• Population Growth –
• Overexploitation –
• Biophilia –
• Umbrella species –
• Endangered Species Act (1973)
• Captive Breeding –
• Biodiversity Hotspot –
• IUCN –
• Extinct –
• Extinct in the Wild –
• Critically endangered –
• Endangered –
• Vulnerable –
• Conservation Dependent –
• Near Threatened –
• Least Concerned –
• Four Factors creating the Basis for the Concern over Extinction – The unprecedented level of threats to
biodiversity; The escalation of the threats to biodiversity; The observation that the threats to biodiversity
are synergistic;
The realization that what harms biodiversity will harm humanity.
• Population & Size & Survival – Births and immigrations add to the population size while
deaths and emigrations reduce the population size.
Population size and survival depend on: The availability of resources The amount of suitable habitat Predation/parasitism Disease Social interactions
• Mechanisms of Extinction in Single Populations –
Demographic uncertainty Environmental uncertainty
‘Natural’ catastrophes Loss of genetic diversity
Mechanisms may interact, compounding the effect on the population.
Population size is critical to survival.
• Minimum Viable Population – the lowest number of individuals needed to
ensure that a population has a selected probability of survival for a set time period without significant loss of evolutionary adaptability.
No MVP is applicable to all species.
• Vulnerability to Extinction – Species that only occur in threatened habitat
types Species that are economically valuable to humans Species that do not have any/much experience of
disturbance Species requiring large
home ranges