Final answer:
Global patterns of species richness are influenced by speciation, extinction, and the dispersion of species, with human activities impacting these processes and consequently affecting biodiversity.
Step-by-step explanation:
The three processes that control global patterns of species richness are speciation, extinction, and the dispersion of species. Speciation is the evolutionary process by which new biological species arise. Extinction is the termination of a species, which reduces biodiversity.
The movement of species, whether through natural dispersion or due to human influence like trade and relocation, changes the distribution and abundance of species globally. High rates of speciation can lead to increased species richness, while high extinction rates can diminish it.
Environmental factors and human activities have a significant impact on both speciation and extinction rates. Moreover, the transportation of new species within and between ecosystems can cause biological homogenization, which poses a threat to global biodiversity.
Human-induced factors such as habitat conversion can lead to losses in avian biodiversity. Understanding the interplay between native and invasive species, niche structures, and environmental characteristics is crucial to appreciating how these factors influence global species distribution and richness.