Past Ecosystems (IQ2)

How do selection pressures within an ecosystem influence evolutionary change?

Paleontological evidence

can reveal progressive changes in the Earth’s environment and atmosphere

Geological evidence

provide information about conditions present and timing of the origin of life (oxic and anoxic atmospheres)

Aboriginal Artwork (Evidence)

suggests that humans were present, flora fauna present at the time, evidence of evolution

Gas Analysis

has helped scientists identify and predict future atmospheric concentrations, especially that of CO2 concentrations and other greenhouse gases

Radiometric dating

a method of estimating the age of subjects or material using the decay rates of radioactive components

Ice Core Drilling

Studies past climate by analysing gases and particles trapped in ancient ice. Annual ice layers (newest to oldest), thickness = rainfall, isotope analysis = pas temps.

Small Mammals

Evolved ~240 mya from reptiles, Oldest mammals in Australia appear in the fossil record ~125–110 mya.

Types of Mammals

Monotremes, marsupials, placental mammals

Sclerophyll Plants

Evolved from rainforest species over from drier conditions. Have tough, evergreen leaves with thick cuticles to reduce water loss. Examples: tea trees, eucalyptus and gum trees