BioL 370

• What are the two mass extinctions known as the Ordovician-Silurian Extinction? The Ordovician-Silurian Extinction occurred around 450-440 million years ago and eliminated 60-70% of all species, including 85% of marine species, likely caused by massive glaciation and sea-level drop.
• What caused the Late Devonian Extinction, and what was its impact? The Late Devonian Extinction occurred approximately 375-360 million years ago, leading to the loss of at least 70% of all species, potentially due to global anoxia triggered by global cooling or oceanic volcanism.
• What is the Great Dying, and what were its causes? The Great Dying, or Permian-Triassic Extinction, occurred about 252 million years ago, eliminating 96% of marine species and 70% of land species, possibly caused by severe volcanic activity, environmental changes, and long-term methane release.
• Describe the Triassic-Jurassic Extinction and its probable causes.: The Triassic-Jurassic Extinction occurred around 201.3 million years ago, resulting in the extinction of 70-75% of terrestrial and marine species. It may have been caused by volcanic eruptions and greenhouse gas emissions, leading to climate change.
• What is known about the Cretaceous-Paleogene Extinction? The Cretaceous-Paleogene Extinction, about 66 million years ago, resulted in the disappearance of 75% of species, including non-avian dinosaurs, and was caused by an asteroid impact creating the Chicxulub Crater, accompanied by volcanic activity known as the Deccan Traps.
• Living Planet Index (LPI): a measure of the state of the world's biological diversity based on population trends of vertebrate species from terrestrial, freshwater and marine habitats
• What is the current trend of the LPI?

  Decline
• What is conservation biology?

  A crisis discipline and holistic.
• Goals of conservation biology today: (1) to investigate and describe the biological diversity of the living world;(2) to understand the effects of human activities on species, genetic variation, communities, and ecosystems;(3) to develop practical interdisciplinary approaches to protecting and restoring biological diversity
• Axioms of conservation biology: 1. Natural communities are the products of coevolutionary processes. 2. Many, if not all, ecological processes have thresholds below and above which they become discontinuous or chaotic.

  3. Genetic and demographic processes have thresholds below which nonadaptive, random forces begin to prevail over adaptive, deterministic forces within populations.

  4. Nature reserves are inherently in disequilibrium for large, rare organisms.
• Normative postulates of conservation biology: 1. diversity of organisms is good

  2. ecological complexity is good

  3. evolution is good

  4. biotic diversity has intrinsic value
• Major threats to Nature: 1. Industrial agriculture

  2. Human Population Growth

  3. Pollution

  4. Habitat destruction/Resource extraction
• Explain the connection between human population growth and species loss: Directly correlated. As humans increase, species decrease.
• Core disciplines in Conservation Biology: population biology, taxonomy, ecology, and genetics
• Conservation was sparked only for: species of utility to humans, such as and fish and trees
• The Preservationist Ethic: Stressed equity - fair distribution of resources -> current & future generations - origins of sustainable use concept
• The Resource Conservation Ethic: Efficiency. Nature = assortment of components that were either useful, useless, or noxious to people
• The Evolutionary-Ecological Land Ethic: Humans as part of the ecosystem - which is complex, evolves, and provides all of the different values emphasized by the differing viewpoints
• Precautionary Principle: a principle based on the belief that action should be taken against a plausible environmental hazard
• 1960-1970 Framing of Conservation: Nature for itself. Species, habitats, and wildlife ecology.
• 1980-1990 Framing of Conservation: Nature despite people. Population biology, natural resource management
• 2000-2005 Framing of Conservation: Nature for people. Ecosystems functions, environmental economics
• 2010 Framing of Conservation: People and Nature. Interdisciplinary, social and ecological sciences.
• The Kuznets Curve: As per capita increases, environmental degradation first increases and then decreases.
• Population Growth: Longer lives, less infant deaths, access to information, increased wealth
• How does Conservation Biology differ from environmentalism? Conservation Biology is a Scientific discipline, Environmentalism = a widespread movement characterized by political and educational activism
• Eight Limitations to BSC: Asexual Reproduction, Hybridization, Different Rates of Evolution, Ring Species, Geographical Barriers, Behavioral Isolation, Extinct or Fossilized Species, Closely Related Species
• Asexual Reproduction: The BSC is less applicable to organisms that reproduce asexually because it is based on the ability to interbreed and produce fertile offspring. In asexual organisms, interbreeding often occurs
• Hybridization: Different species can interbreed and produce viable offspring hybrids. For example, some species can produce fertile hybrids, blurring the clear boundaries between species.
• Different Rates of Evolution: The BSC assumes a uniform rate of evolution, but different populations within a species may evolve at different rates.
• Ring Species: A series of populations can interbreed with adjacent populations, but two geographically distant populations cannot interbreed successfully. The result is a "ring" of interbreeding populations
• Geographical Barriers: Species that are separated by geographical barriers but could potentially interbreed if brought into contact. Geographical isolation can prevent interbreeding even if the organisms are capable of reproducing with one another
• Behavioral Isolation: Behavioral differences can also prevent successful mating. The BSC may not adequately address cases where behavioral factors play a significant role in reproductive isolation.
• Extinct or Fossilized Species: The BSC is difficult to apply to extinct or fossilized species where direct observation of reproductive isolation is not possible.
• Closely Related Species: The BSC is more effective for distinguishing between distantly related species, but it may be less useful for closely related species that share recent common ancestors. Other criteria such as genetic divergence may be more informative.
• Morphological species definition: is morphologically, physiologically or biochemically distinct from other groups in some important characteristic
• Biological species definition: Interbreed in the wild to produce viable, fertile offspring
• Biophilia: the innate tendency to focus on life and lifelike processes
• Trends in biodiversity (terrestrial): diversity tends to increase with

  1) decreasing elevation,

  2) increasing solar radiation,

  3) increasing precipitation
• Latitudinal diversity gradients: The gradient involves high species' numbers near the equator (at low latitudes) and lower numbers of species at high latitudes.