Classification - Diversity of Species

Classification - Diversity of Species

• Taxon: Any named group of organisms distinct enough for categorization.
• Phylogenetics: The study of evolutionary relationships among groups of organisms.
• Phylogenetic tree: A diagram used to visualize evolutionary relationships.
• Biological Species Concept: Species are populations that interbreed or have the potential to interbreed in nature.
• Evolutionary Species Concept: A lineage where gene flow exists, representing a distinct evolutionary path.
• Ecological Species Concept: A group of organisms adapted to a specific ecological niche.
• Reproductive Species: Organisms that naturally produce fertile offspring of both sexes.
• Isolation Species: Populations that are reproductively isolated from others.
• Genetic Species: Individuals or populations with similar DNA.
• Evolutionarily Significant Unit (ESU): Distinct populations for conservation purposes.
• Asexual Eukaryotes & Prokaryotes: Share some "species" characteristics, but not all.

Biodiversity

• Biodiversity: The variation of life forms within species, ecosystems, biomes, or the entire planet.
• Descent with Modification: Evolutionary processes create diversity at all biological levels, including: species, organisms, and molecules.

Natural Selection

• Three Tenets of Natural Selection:
  • More offspring are produced than can survive.
  • Traits vary among individuals.
  • These trait differences are heritable.
  • Evolution occurs through changes in heritable traits controlled by genes within an organism's genome.
• Genotype: An organism's genetic makeup.
• Phenotype: An organism's observable traits.

Heredity and Variation

• Variation arises from genetic diversity, which includes:
  • Mutations in the genetic makeup of organisms.
  • Sexual Reproduction which mixes genes in offspring.
  • Migration between populations, introducing new genes.
• Mutation: Changes in the DNA or RNA sequence.
  • Caused by radiation, viruses, mutagenic chemicals, or errors during meiosis.
  • Spontaneous mutations occur naturally.
  • Induced mutations are caused by external factors.
• Deep Homology: Similar genetic mechanisms governing growth and development across different species.

Sexual Reproduction

• Sexual reproduction results in offspring with a random mixture of genetic information from their parents.

Natural Selection and Environment

• Tolerance Limits: Minimum and maximum levels of environmental factors that allow a species to survive and reproduce.
• Habitat: The environment where an organism lives.
• Ecological Niche: The role an organism plays in its ecosystem, including its resources and interactions with other organisms.

Coral Symbiosis

• Coral: Predacious animals, related to jellyfish and anemones.
• Zooxanthellae: Microalgae living symbiotically with corals.
• Coral-Zooxanthellae Relationship:
  • Coral provides nutrients and CO2.
  • Zooxanthellae provide fixed carbon (food) and oxygen.

Anemone-Clownfish-Zooxanthellae Symbiosis

• Mutualism: All three species benefit from the relationship.
  • Clownfish: Protection from the anemone.
  • Zooxanthellae: Nutrients from the fish via the anemone.
  • Anemone: Carbon from the zooxanthellae.

Biological Communities

• Species: Organisms with a close genetic relationship.
• Population: All members of a single species living in the same place at the same time.
• Biological Community: All species living together in the same place at the same time.
• Ecosystem: A biological community and its environment.

Ecosystem Structure and Productivity

• Productivity: The amount of energy or biomass produced in an ecosystem over time.
• Primary Producers (Autotrophs): Plants and photosynthetic bacteria, the lowest trophic level.
• Secondary Producers (Primary Consumers): Herbivores that feed on plants.
• Tertiary Producers (Secondary Consumers): Carnivores that feed on herbivores.
• Quaternary Producers (Tertiary Consumers): Top predators that feed on other carnivores.
• Omnivores: Feed on both plants and animals.

Energy for Life

• Solar Energy: The primary source of energy for life, used in photosynthesis.
• Cellular Respiration: The process of converting food into usable energy.

Biomes

• Biome: A geographically extensive ecosystem characterized by its climate, soil, and biological communities.
• Factors determining biomes:
  • Temperature: Equatorial regions are typically warmer than high-latitude or high-altitude areas.
  • Rainfall: Precipitation levels vary across biomes.

Terrestrial Biomes

• Tundra: Cold, treeless biome with low-growing vegetation, found at high latitudes (arctic) and altitudes (alpine).
• Boreal Forest: Coniferous forest found in northern subarctic regions.
• Montane Forest: A subalpine analogue of the boreal forest, found at higher elevations.

Freshwater Biomes

• Lentic: Still water habitats, like lakes and ponds.
• Lotic: Flowing water habitats, like rivers and streams.
• Wetlands: Shallow, seasonally or continuously wet habitats.
  • Marsh: Dominated by reeds.
  • Swamp: Usually forested.
  • Bog: Nutrient-poor and acidic.
  • Fen: Nutrient-rich and often alkaline.

Marine Biomes

• Open Ocean: Deep, nutrient-poor water, considered a marine desert.
• Continental Shelf Waters: Shallow, nutrient-rich waters.
• Upwellings: Areas with significant vertical water movement, bringing up nutrients.
• Estuaries: Where rivers meet the sea.
• Seashores: Coastal environments.
• Coral Reefs: Diverse, complex ecosystems in warm, clear waters.

Succession

• Succession: The process of change over time in the species present in a given place.
• Primary Succession: Succession starting on a previously uncolonized substrate.
• Secondary Succession: Succession starting on a previously colonized substrate.

Primary Succession

• Fresh Substrate: Nutrient-poor and undevelopd.
• Pioneer Species: Rapidly-growing organisms with low investment in hard structures (e.g., vines).
• Changes Over Time: Pioneer species modify the substrate, making it suitable for later colonists.
• Competitive Domination: Over time, competitively dominant species replace the pioneer species, often in a predictable sequence.

Secondary Succession

• Suitable Substrate: Existing soil or substrate suitable for immediate colonization.
• Influence of Surrounding Communities: Neighboring communities influence species composition.
• Changes Over Time: Pioneer species are gradually replaced by taller, woodier species.

Mud Dauber Wasps

• Ectoparasitoid: A parasite that lives outside its host and eventually kills it.
• Mud Dauber Wasp Nests: Contain caterpillars that serve as food for the developing wasp larvae.