Continental Drift

How the movement of Earth's landmasses has influenced the distribution and evolution of life over millions of years

CAPS Grade 10 Life Sciences

Continental drift helps explain why related fossils are found on continents that are now far apart. In this topic, learners must connect Pangea, Gondwanaland, and fossil evidence to the idea that species distributions changed as landmasses slowly separated.

Key Concepts

Pangea: The Supercontinent (250 mya)

Laurasia (North)

Formed the northern portion of Pangea after the breakup.

North America
Europe
Asia

Gondwanaland (South)

Formed the southern portion of Pangea after the breakup.

Africa
South America
India
Australia
Antarctica

Alfred Wegener (1880-1930)

German meteorologist and geophysicist who proposed the theory of Continental Drift in 1912. He suggested that continents "drifted" apart over millions of years due to the movement of tectonic plates.

Quick Check

1. What was the name of the single supercontinent that existed 250 million years ago?

Laurasia Gondwanaland Pangea Rodinia

Biological Evidence (Biogeography)

Biogeography provides compelling evidence for the theory of Continental Drift through the distribution of related fossils and living species across continents now separated by oceans.

Glossopteris

Seed Fern (250 mya)

Fossils of this seed fern have been discovered across multiple continents.

Found in:

Africa South America India Australia Antarctica

Why this matters: The seeds of Glossopteris were too heavy to be dispersed by wind across oceans, proving these landmasses were once connected.

Lystrosaurus

Mammal-like Reptile

This herbivorous reptile lived during the Permian and Triassic periods.

Found in:

Africa Antarctica India China

Significance: The presence of Lystrosaurus fossils in both Africa and Antarctica supports the idea these continents were once connected.

Ratites (Flightless Birds)

Living Evidence

Flightless birds that share a common ancestor from Gondwanaland.

Ostrich

Africa

Emu

Australia

Rhea

South America

Kiwi

New Zealand

Fossil Distribution Challenge

Drag each fossil to the correct supercontinent where it is found.

Glossopteris

Lystrosaurus

Ostrich

Emu

Rhea

Gondwanaland

Laurasia

Other

2. Why are Glossopteris fossils found on continents now separated by oceans?

Seeds were carried by wind Seeds floated across oceans Continents were once connected Birds carried the seeds

Impact on Biodiversity

Speciation

As continents separated, populations became geographically isolated, leading to speciation where these populations evolved into distinct species.

Example: Ratites (ostrich, emu, rhea) evolved from a common ancestor on Gondwanaland.

Climate Change

The movement of continents affected global climate patterns as landmasses drifted to new latitudes.

Example: As Antarctica drifted southward, it experienced cooling, leading to mass extinctions of species that couldn't adapt.