A4. 2 Flashcards
Conservation of Biology
Biodiversity
What is Biodiversity?
- The Variety or multiformity of living organisms in all its forms, levels and combinations.
Biodiversity
What is species Richness?
- A measure of biodiversity that specifically considers the number of different species in a community.
- Total number of species within a given area = more = richer.
- Species richness is a strong indicator of high biodiversity.
Biodiversity
What is Species Evenness?
- Indicator of how balanced an ecosystem is
- Total number of individuals of a given species within a given area
- Health ecosystem: not only lots of organisms, but lots of EACH organism, rather than one or two more dominant species.
Biodiversity
What is meant by “Gene Pool?”
- Gene pools of a population are made up by all the different versions of genes (all the alleles)
- Can be specific to a single gene/trait or be in reference to the entire genome.
- Bigger gene pool –> more different alleles –> more diversity and is an idnicator of a healthier ecosystem.
Biodiversity
(Types of Biodiversity)
Ecosystem Diversity
- Refers to the variety in the combinations of species living together in communities.
- the variety of different habitats, communities and ecological processes.
Biodiversity
(Typces of Biodiversity)
Species Diversity
- Refers to a smaller scale of biodiversity —> narrows into within one habitat/ community.
- Considers how many unique species exist in that community.
- Healthy ecosystems have an even distribution of the species as well.
Biodiversity
(Types of Biodiversity)
Genetic Diversity
- Within a single species, looking at how unqiue different members of a species are —> genetic differences.
- The more different alleles and genetic combinations —> greater the biodiversity of that species.
Biodiversity
Past and Present Biodiversity
- Overall species biodiversity seems to be declining (over last couple of years)
- Rates of extinction are higher than rates of speciation –> lower number of species currently than in recent history
- Fossil fuel evidence however suggests more species now than in distant past.
Biodiversity
Anthropogenic Species Extinction
- Looking specifically at the enxtinction of species due to human activities.
Biodiversity
Overharvesting
(Antropogenic cause of extinction)
- Humans removal of plants and animals for food, medicine and materials (such as timber and wool) at a FASTER rate than a species can reproduce
- Fishing rates (overfishing) likely will lead to the extinction of many species
- Includes poaching and excessive hunting
Biodiversity
Habitat Destruction
(Anthropogenic Cause of Extinction)
- destroying ecosystems such as forests in order for us in agriculture (initially) or for creation of homes and human infrastructure (current biggest contributor)
Biodiversity
Invasive Species
(Anthropogenic Causes of Extinction)
- introduction of an alien species who then outcompete native species, which leads to their extinction.
Biodiversity
Pollution
(Anthropogenic Causes of Extinction)
- the industrial revolution brought the introduction of release of substances into the environment
- can be emissions into the atmosphere/ litter ending up in the oceans
- impact on living organisms can be direct/ indirect but have widespread effects
Biodiversity
Global Climate Change
(Anthropogenic Causes of Extinction)
- normally species will evolve to the changes in their environment if the changes are gradual
- the rate of climate change is faster than the rate of natural selection, meaning many species are no longer able to tolerate the abiotic conditions of their habitat.
Biodiversity
Causes of Ecosystem Loss
- Land use for agriculture (highest cause)
- Land use for urbanisation (for buildings)
- Overharvesting for resources including food
- Mining and smelting both directly destroy land and release pollution.