The outer layer of the Earth, the lithosphere, is divided into eight major and many minor plates.
Plate tectonics is a concept explaining how these plates move and interact in relation to each
other. There are three kinds of plate tectonic boundaries, including divergent, convergent, and
transform plate boundaries; the edges of adjacent plates can move parallel to each other, be
separated from each other, or collide. While primarily associated with the shaping of the Earth's
surface, plate tectonics also plays a significant role in influencing biological evolution.
Speciation is the evolutionary process where populations evolve to form distinct species,
occurring when a group within a species separates from other members of its species and
develops its own unique characteristics. One of the primary mechanisms through which plate
tectonics can drive speciation is geographical isolation; as tectonic plates move around the
earth’s mantle, they produce barriers such as mountain ranges, oceans and rift valleys that can
lead to isolation of gene pools, fostering the development of unique traits in plants and animals.
For example, the Himalayas is the result of the Indian and Eurasian plates colliding 50 million
years ago. When they crashed, tall mountain ranges and deep valleys were formed, equipping
the Himalayas with a mix of different altitudes, climates, and landscapes, from warm foothills to
chilly mountaintops. At the same time, those mountain ranges acted as a physical barrier that
many species could not cross, which allowed the isolation of gene pools. In other words, this
caused many new unique animals and plants to evolve and grow in different areas of the
mountain, creating diverse environments each with its own set of conditions that those species
learned to adapt to. Over time, these isolated populations may diverge, eventually leading to
the formation of distinct species.
Another example of speciation through geographic isolation is when tectonic plates separate
(divergent boundary). The Mid-Atlantic Ridge, for example, is a divergent boundary between the
North American and Eurasian Plates on one side and the South American and African Plates on
the other. When these plates separated, they created a gap, forming new ecosystems within
those gaps. For instance, the rift created hydrothermal vents, giving rise to a whole new
ecosystem in the ocean where highly-resistance creatures resided.
In conclusion, plate tectonics plays a crucial role in influencing speciation. The earth’s ever-
shifting tectonic plates can create diverse habitats or alter existing ones and foster geographical
isolation. These processes, in turn, contribute to the evolution and diversification of life on our
planet.