Calculating biodiversity Flashcards
What is Simpson’s index of diversity (D)?
takes into accouunt richness and eveness between 0 and 1
1 most diversity
quadrats have to be used to estimate the number of species and individuals
What is the meaning of the letters for Simpson’s index of diversity?
N = total number of organisms of all species
n = total number of organisms of a particular species
What can be said about areas with low biodiversity?
simple food webs
few successful species
stressful system with few ecological niches
changes to the environemnt have major effect on the ecosystem
What is genetic biodiversity?
the difference in alleles between members of a species
Why is genetic biodiversity important?
makes the species more likely to be able to adapt to changes in their environment, therefore less likely to become extinct
this is because some members contain an advantageous allele that will be passed on
What increases genetic biodiversity?
mutatations - creating new alleles
interbreeding between different population - gene flow - alleles tranferred between two populations
What decreases genetic biodiversity?
selective breeding - artificial selection - only animals with advantageous characteristics are bred
artificial cloning
natural selection
fouder effect
genetic drift - alleles may cease to exit as it is a random process, more pronounced in poulations with an already low genetic biodiversity
What is polymorphism?
measuring polymorphism
polymorphic genes have more than one allele
e.g. alles for the immunoglobulin gene, plays a role in blood type
most are monomorphic
How is genetic biodiversity quantified?
propotion of polymorphic gene loci = (number of polymorphic gene loci) / (total number of loci)
loci - refers to the position of the gene on a chromosome
greater propion of polymorphic gene loci - the greater the genetic biodiversity
