Technological changes assisting the understanding of the origin of

life

Year 11 Biology

• Plates tectonics and continental drift

• Radiometric dating

• Other methods

Plate tectonics• Geologists have developed our

knowledge of the structure of the Earth using seismology, which is the study of the pressure or shock waves from earth quakes

• Towards the end of the 19th century they developed seismographs

• Seismographs were used to measure and record the wave patterns from earthquakes

• Geologists have also studied changes in the earths magnetic field and the composition of meteorites and volcanoes to learn more about the Earth.

• Biologists are interested in the structure of the earth because the changing structure of the surface layers influenced the origin of the evolution of life

Continental drift

• In the beginning of the 17th century, the English philosopher Francis Bacon noted that the east coast of America and the west coast of Africa looked as though they could fit together like a jigsaw puzzle.

• The diagram above shows a map fit of the continental masses--this is a piece of data used to confirm that the continents drifted-- the concept of continental drift initiated the rock plate concept

• This observation was supported by the remains of organisms embedded in rocks (fossils)

• Remains of identical species of plants and animals were found on land masses that could fit together, but were separated by oceans

• Scientists agreed that these land masses must have once been one

• German geologist Wegner in 1912 suggested that these land masses broke and drifted apart

• Nobody could explain how this happened until 1965 when a Canadian geologist J. Tuzo Wilson, supported the idea of continental drift and introduced the idea of sea floor spreading

• Sea floor spreading- when ridges in the sea floor produced new material and spread apart.

• His ideas were based on the evidence from magnetic surveys of oceans ridges, which are large gashes in the ocean floor.