Diversity of species Flashcards
What is alpha diversity?
The number of species present within a specific habitat.
What is Beta diversity?
The rate at which a species changes from one area to another.
What is gamma diversity?
The total species present within a broad biogeographic region (e.g. The rainforest).
What is species evenness?
Population sizes of different species are roughly equal.
What is the Simpsons diversity index used for?
To calculate alpha diversity.
What are the advantages of species richness as a measure of biodiversity?
Measurable in practice
It can act as a surrogate for other measures of biodiversity.
What are the limitations of species richness as a measure of biodiversity?
Multiple species concepts can result in different measures of species richness.
1. Biological species - groups of interbreeding individuals don’t naturally interbreed with other groups.
- Ecological species - species occupy different ecological niches which evolve separately.
- Morphological species - species separated from one another inherit distinct heritable characteristics.
- Phylogenetic species- monophyletic groups can be distinct from other groups.
Of the four measures of biodiversity which ones are most used?
Morphological and phylogenetic concepts are easier to test and more practical.
Biological and ecological concepts are more meaningful however they are difficult to test.
What are the limitations of morphological species ID?
- Based on morphology
- Hampered by a high proportion of undescribed species.
- Differences in expertise, experience, and opinions of identifiers can lead to differences in ecological assessment.
What are Reference libraries?
Institutions that are required to match sequences to species. This must be comprehensive and reliable, species should be linked to voucher specimens and appropriate metadata.
What is environmental DNA (eDNA)?
These are parts of organisms that are shed into the environment, which can be detected by environmental samples (e.g. Soil, Water, etc)
What are active surveys?
Using specific primers to target eDNA.
What are passive surveys?
It’s the use of massively parallel sequencing to barcode all organisms in a sample.
What are operational taxonomic units? (OTUs)
Groups of sequences considered to belong to a single spp. Only identified by assigning sequence similarity threshold.
What are the problems with OTUs?
If the marker is not sufficiently variable the single OTU may contain sequences from multiple species. This means species may be misidentified.
