4.1 - Intro to Biodiversity Flashcards
What are the three categories/levels of biodiversity?
- Ecosystem diversity
- Species diversity
- Genetic diversity
What is ecosystem diversity?
the number of diff. habitats available in a given area
What is species diversity?
the number of diff. species in an ecosystem and the balance or evenness of the pop. sizes of all species in the ecosystem
What is genetic diversity?
how different the genes are of individuals within a population (group of the same species)
What happens with higher diversity?
Higher biodiversity = higher ecosystem/population health
What is richness?
(r) is just the total number of different species found in an ecosystem
What is Evenness?
is a measure of how all of the individual organisms in an ecosystem are balanced between the different species
What does higher richness indicate?
- High (r) is generally a good sign of ecosystem health
- more species means more quality resources like H2O & soil
What does evenness indicate?
Evenness indicates if there are one or two dominant species, or if pop. sizes are well balanced
What is genetic diversity?
measure of how different the genomes (set of genes) are of the individuals within a population of a given species
How is there genetic diversity in every population and ecosystem?
There is genetic diversity in all pops. because random mutations in copying of DNA & recombination of chromosomes in sex cells of parents leads to new gene combinations & new traits in offspring
What is a result from higher genetic diversity?
- The more genetic diversity in a pop. the better the population can respond to env. Stressors like drought, disease, or famine
- More gen. div. = higher chance that some of the individuals in a pop. have traits that allow them to survive the env. stressor
What is a bottleneck event?
An env. disturbance (natural disaster/human hab. destruction) that drastically reduces pop. size & kills organisms regardless of their genome
What are the results of a bottleneck event?
- Surviving pop. is smaller and because individuals died randomly, it doesn’t represent the genetic diversity of the original pop.
- Bottleneck events reduce genetic diversity
- Because the pop. is smaller & less genetically diverse, it’s even more vulnerable to future env. disturbances
What is inbreeding?
Inbreeding is when organisms mate with closely related “family” members