How ice ages drive biodiversity in temperate areas but not tropics

Описание: Glaciers, like those we see today in Greenland and Antarctica, may seem remote, but their influence on life reaches across the entire planet. Here, I explore how Earth’s climate history, has fundamentally shaped the patterns of biodiversity we see today.

Approximately every 100,000 years, subtle changes in Earth's orbit and axial tilt trigger massive global shifts in climate, ushering in ice ages that cover up to a quarter of the planet’s surface with glaciers, known as the Milankovitch cycles. During the last glacial maximum, around 20,000 years ago, much of the Northern hemisphere was buried under ice, dramatically altering habitats and driving species into climate refugia, isolated pockets where conditions remained stable enough for survival.

As the ice sheets retreated, species recolonised newly available land, expanding their ranges and in some cases evolving into new species along the way. This has resulted in temperate zones being dominated by relatively young, widespread species with low beta diversity: less variation in species turnover from one area to the next.
In stark contrast, the tropics, largely untouched by glaciation, contain extremely high biodiversity, including many ancient lineages and a striking degree of localised species. This contrast highlights how geological processes, like glaciation, play a pivotal role in shaping evolutionary history, ecosystem structure, and conservation priorities today.
I discuss:
What causes ice ages (Milankovitch cycles)
The extent and impact of the Last Glacial Maximum
Ice age refugia and species survival
Patterns of post-glacial recolonization
Differences in biodiversity between temperate and tropical regions
Implications for modern conservation science
This video is designed for students, researchers, and educators in ecology, conservation biology, evolutionary biology, and earth sciences—anyone interested in the deep-time processes that continue to shape the living world.
Filmed by Adam Lyberth.