My Science School

The remains of ancient animals, or ‘fossils’, tell us that our planet and the life on it were once very different from today. Throughout the ages, the Earth and its climate have changed, sometimes dramatically – like the coming of the ice ages. The most recent ice age began 70,000 years ago, and lasted for 60,000 years.

Plants and animals living on Earth have adapted to changes in the planet, to improve their chances of survival. Sometimes plants and animals have also caused changes to the Earth. For example, the soil in your garden was partly formed from the rotting remains of dead plants and animals, called ‘humus’.

During the ice age, the Earth’s land was mainly covered with snow and ice.

The Earth in a day

Imagine the changes of the Earth’s lifetime squashed to fit into a 24-hour day. On this scale, there would be no life on Earth until about 6.30am, when the first microscopic plants and animals would appear. Large animals with backbones, like fish, would not appear until about 9.15pm. The first plants would appear about 9.45pm and some fish would take to the land at 10.00pm. Reptiles would appear at about 10.30pm. Dinosaurs and early mammals would be living on Earth about 11 pm, but mammals would only become common about 11.40pm. People would appear on Earth 40 seconds before midnight and the first written history would be documented about ten seconds before midnight.