Lecture 1: What is Biodiversity? Flashcards
Biodiversity is
the variety of life, in all its manifestations. IT encompasses all forms, levels and combinations of natural variation.
3 different categories of biodiversity
Ecological, Genetic and organismal. All have populations in common.
Ecological diversity
Biomes bioregions Landscapes Ecosystems Habitats Niches Populations
Genetic diversity
Populations Individuals Chromosomes Genes Nucleotides
Organismal diversity
Domains of kingdoms Phyla Families Genera species subspecies populations individuals
Example of biodiversity plant kingdom. Why they so fascinating?
- the major primary producer
- represent an est 90% of all biomass
- single most important influence on Earth’s environment and global change
- food, drugs,materials and fuel.
- aesthetically pleasing
- jobs!
Cambrian life in the ocean and on the land before the advent of land plants:
Only one carbon cycle as only life in the oceans.
Origin of land plants and now:
2 carbon cycles as life on land and in ocean.
Life on earth before the origin of land plants:
- Pond scum-free living organisms in bodies of freshwater (rivers, lakes etc.)
- Microbial mats on damp surfaces periodically inundated with water (lake margins, estuary mudflats etc.)
- Biological soil crusts on rudimentary rocks
- Within or beneath rocks as endoliths
whats an endoliths
An endolith is an organism that lives inside rock, coral, animal shells, or in the pores between mineral grains of a rock.
Life’s challenges from salt water to land
salt water -> river water -> land
Physiological problems for when migrating from an aquatic to subaerial habitat:
- water balance
- availability of essential nutrients and gases
- support
- UV protection
- Necessary alterations in reproductive strategy
Water balance for when migrating form aquatic -> subaerial habitat:
Plants are no longer bathed in water. Therefore they utilize rhizoids/roots [collection], xylem [transport], cuticle and stomata [desiccation avoidance])
essential nutrients and gases for when migrating form aquatic -> subaerial habitat:
(Plants are no longer bathed in water containing dissolved essential nutrients and gases. Therefore, they have to collect them from the soil and atmosphere using roots and stomata)
Support for when migrating form aquatic -> subaerial habitat:
Plants no longer supported in an aquatic medium. Therefore, they use lignified conducting tissues to provide support)