Evolution
Name the two scientists responsibly known for developing the theory of evolution by natural selection.
Charles Darwin and Alfred Russel Wallace
Biodiversity within a population is essential to provide ___________ for the occurrence of _________.
Biodiversity within a population is essential to provide variability for the occurrence of adaptations.
Define 'adaptation' in Biology.
An adaptation is a characteristic that an organism has inherited and that makes it better suited to survive its environment.
What is an ecosystem?
An ecosystem is the combination of all the organisms living within a community (a group of different populations in an area or habitat) and non-living features with which they interact.
Abiotic and Biotic factors exert selection pressures that do what?
Abiotic and Biotic factors exert selection pressures that influence the survival and reproduction of an individual, population or species.
Darwin suggested that the finches on the Galapagos had original ancestors from where?
South America
Define 'Biodiversity'
Biodiversity is the variety of all living things; the different plants, animals and micro-organisms, the genetic information they contain and the ecosystems they form.
What is meant by 'structural adaptations'?
A structural adaptation refers to how an organism is built or structured so that it can survive in its environment. They are physical features on both the outside and the inside of the organism.
An ecosystem is comprised of two kinds of factors. Name them.
Abiotic factors and Biotic factors
What is the most common method of counting when it comes to measuring plant abundance?
Quadrats (1m x 1m square) are used to estimate percentage cover for plant species.
Survival of the fittest. Natural selection gave rise to their ideas on speciation - formation of new species. Formation of new species can occur when a population becomes isolated from the original population.
Biodiversity is usually explored at three levels. What are they?
Genetic diversity, Species diversity and Ecosystem diversity.
What are the 3 types of adaptations that are found in organisms?
- Structural
- Physiological
- Behavioural
Give two examples of abiotic factors
Sunlight, temperature, humidity, moisture, wind, water current, pH, soil type, salinity, minerals and nutrient availability.
The distribution of a species describes where it is found and the abundance of a species determines how many individuals of that species live throughout the ecosystem.
What idea is the theory based on?
The theory is based on the idea that living things came from a common ancestor and that some populations moved into new habitats where they adapted over time to their environments, leading to diversity of life.
Explain one of the following levels of biodiversity:
- Genetic diversity
- Species diversity
- Ecosystem diversity
Genetic diversity - total number of genetic characteristics in the genetic make-up of a species.
Species diversity - measure of diversity of different species in an ecological community.
Ecosystem diversity - variation of different ecosystems within a region.
Explain the three types of adaptations
Structural - how the organism is built or structured.
Physiological - how an organism functions.
Behavioural - how an organism acts or behaves.
What do Abiotic and Biotic factors act on and affect?
Abiotic and Biotic factors act on the characteristics of the organisms and affect the ability of an organism to survive and reproduce in a particular environment.
Explain the 'mark-release-recapture' method and why it is used.
The 'mark-release-recapture' technique is used by Ecologists to measure faster animal popualtions. The animals are captured, tagged and then released. Data is also collected on the animals captured; such as size, weight, gender, juvenile or adult, etc.
Name 2 examples of limitations of paleontology as evidence
- Fossil record is incomplete
- Soft-bodied organisms are not represented well, don't fossilise well
- Bias towards organisms with hard-bodied parts
- Hard to determine the ages of fossils accurately, especially past 50 000 years of age
Name the top 5 causes of loss of biodiversity.
- Habitat loss
- Invasive species
- Overexploitation
- Pollution
- Climate change
In Australia, the Thorny Devil (Moloch horridus) is a small lizard that lives in the Western Australian desert. Its body is covered with large prickly spikes. What would the purpose of these spikes be? What kind of adaptation would this be an example of?
The prickly spikes would deter predators and are an example of a structural adaptation.
What is a niche?
A niche is the part of an ecosystem where an organism lives. It refers to all the resources the species uses, both biotic and abiotic. Due to competition, sometimes species are not able to occupy their fundamental niche, they will resort to a realised niche.
Explain what 'transects' are and how they are used.
'Transects' are usually used in large areas to help show variation of species. It is a narrow strip that crosses the entire area that is studied. This information regarding distribution and abundance can be used to predict possible responses when faced with selection pressures.