"the diversity that exists among different geographies" are alpha biodiversity beta biodiversity gamma biodiversity delta biodiversity

The diversity that exists among different geographies is typically referred to as Beta Biodiversity.

Here's a step-by-step explanation:

1. Alpha Biodiversity refers to the diversity within a particular area or ecosystem, and is usually expressed by the number of species in that ecosystem.

2. Beta Biodiversity refers to the variation in species diversity between ecosystems or geographies. This can refer to the change in species diversity from one habitat to another within a geographical area, or the diversity between different geographical areas.

3. Gamma Biodiversity refers to the overall diversity for different ecosystems within a region or across the entire globe.

4. Delta Biodiversity is not a commonly used term in biodiversity studies.

So, when we talk about the diversity that exists among different geographies, we are referring to Beta Biodiversity.