Bio-diversity and Evolution (page 1 and 2)

Biodiversity - measure of the number of species on the planet.

Extinction - loss of species.

Human alteration to habitat is the single greatest threat to bio-diversity on Earth.

Species conservation - the planned preservation of wildlife.

Evolution

• process by which new species are formed from pre-existing ones over very long periods of time.
• the theory of evolution was first put forward by Charles Darwin.
• He proposed natural selection as the force that causes change in population.

Adaptive radiation in the finches of the Galapagos Islands

• Darwin travelled to South America and the Galapagos Islands in 1832.
• The islands were formed in recent geological time as a result of volcanic activity.
• Task was to observe, describe and classify plants and animals.
• He also collected fossils in rocks which showed him that different life-forms had gone through many changes in the past.
• Studied 14 different species of finches
• Finches may have reached the…