Lecture 1 - Biological diversity Flashcards
How are beetles an example of diversity?
- 25% of all animals
- Successful co-evolution with plants and absorbing microbes to expand to cellulose diet
How are viruses an example of nanoscale diversity?
- Quick evolution
- Huge morphological and specialisation diversity
What art 2 examples of diversity we can’t sense?
- Fish with unique UV markings
- Moth pectinate antennae for pheromones
Define species
Populations whose members mate with each other and can/could produce fertile offspring
What are 2 issues with the species concept?
- Useful but not always realistic
- Species are under constant evolution
What are 2 reasons why the species concept is fundamental?
- Need a unit of measurement for conservation
- Need to know species for ecosystem management
Describe the pathway of increasing complexity in the hierarchical organisation of biodiversity
Atom, molecule, macromolecule, organelle, cell, tissue, organ, organism, species, population, community
Define genotype and phenotype and how phenotypes arise
- Genotype = genetic make up
- Phenotype = observable characteristics from genotype x environment
What is taxonomy and how was it done before genetic analysis?
- Morphology of organism
- Measure width and length of wings, interocular distance, height and width etc
Describe the species classification by Linnaeus
Kingdom, Phylum, Class, Order, Family, Genus, Species (King Philip Came Over For Good Soup)
What is the estimated set of values describing the number of species on Earth?
8.7 million and 3 trillion
What is the percentage of assessed species under threat and which species are noted at highest risk?
28% of assessed species esp amphibians
Give 2 reasons why it’s difficult to identify species
- Taxonomic morphological diversity x genetic diversity
- Diversity within species
Give 2 examples of diversity within species
- Sexual dimorphism eg sex determined by social hierarchy as in protogynous sequential hermaphrodite fish
- Different species mimicking another eg toxic vs normal
Define cryptic species diversity
Species with similar morphology aren’t always genetically similar
What is the significance of cryptic species in conservation management and biodiversity? Use blue mussels as an example
- Blue mussels filter water to lower high eutrophication and as bioindicator for water quality
- Species decline unnoticed eg native vs similar exotic = using different species for water quality gives inaccurate data
- Knock on effects = different excretion = different P and N available for seaweeds etc
What are the 2 functions of food webs?
- Visualise species connectedness, energy flow, functional relationships
- In/direct interactions
What are the 2 trophic categories?
- Autotrophs (plants) = use inorganic materials to make organics
- Heterotrophs (animals) = get energy from breaking down organics made by others
List the 5 components of a simple food web and the energy loss between each
- Level 1 = primary producers (plants)
- Level 2 = herbivores
- Level 3 = primary carnivores
- Level 4 = secondary carnivores
- Detritivores = eat all levels
10% energy loss between each level
How are the number of trophic levels determined using physics?
2nd law of thermodynamics = energy never transferred 100% efficiency ie some lost
How is the length of a food chain determined? Are aquatic or terrestrial food chains longer and why?
- Depends on energy available
- Aquatic systems more efficient bc huge biomass of phytoplankton and more efficient energy transfer bc don’t produce heat
What do direct vs indirect lines on a food web refer to?
- Direct lines = animals that eat each other
- Indirect lines = how animals interact eg A and B competition + predators eat only A = A and B’s competition affected
