Calculating biodiversity 4.2.4 Flashcards
Define species richness
The number of different species living in a habitat
Define species evenness
A comparison of the number of individuals of each species living in a community
What is Simpsons index of diversity?
A way to measure species diversity that takes into account species richness and species evenness
How do you interpret Simpsons index of diversity?
- Always get a value between 0 and 1
- High value (closer to 1) = more diverse, can usually cope with change
- Low value (close to 0) = less stable and easily damaged by change
Which animals may have limited genetic diversity?
- Captive animals in zoos
- Rare breeds/pedigree animals
What can aid isolated populations of species?
Assessing their genetic diversity can help to assess the value of that population as a resource for conservation
Why is genetic diversity important?
If genetic diversity is low, then the species may be more susceptible to changes in the environment. The whole population could then be wiped out by a single event or disease
Define polymorphism
When a gene has more than one allele e.g. hair colour, eye colour and blood type.
Define monomorphism
When a gene has only one allele. Most genes are ‘monomorphic’ which ensures that the basic structure of a species is similar
What is the locus?
Where on the chromosome the alleles are
How is the proportion of polymorphic gene loci calculated?
(number of polymorphic gene loci) DIVIDED BY (total number of loci)
