what will happen if the world is without any other animals except humans

If the world were to have no other animals except humans, several significant consequences would arise: 1. **Ecological Impact**: Animals are integral parts of various ecosystems, and their absence would disrupt ecological balance, leading to unforeseen cascading effects on plant life and habitats. 2. **Loss of Biodiversity**: Biodiversity is essential for maintaining ecosystem services, which include regulation of ecosystems, such as pollination, seed dispersal, and pest control. 3. **Pollination Issues**: Many plants rely on insects and other animals for pollination. Without these pollinators, there would be a significant impact on agriculture and food production. 4. **Disruption of Food Chains**: The loss of animals would fundamentally alter food chains, with potential collapses of ecosystems that depend on predators, herbivores, and decomposers. 5. **Decreased Soil Fertility**: Many animals play roles in recycling nutrients and maintaining soil health, which is vital for plant growth. 6. **Impact on Human Health**: Some animals are essential for medical research and the development of new drugs, including those derived from substances found in animal venom or bodies. 7. **Cultural and Psychological Effects**: Animals have been a part of human culture and folklore throughout history. Their absence could lead to a sense of isolation and loss, affecting mental health and cultural richness. 8. **Economic Implications**: Industries that rely on animals, such as livestock farming, fisheries, and tourism, would collapse, leading to economic losses and unemployment. 9. **Increased Disease Risk**: Some animals can serve as reservoirs for diseases, and their absence might alter the dynamics of disease transmission among humans, potentially leading to unforeseen health crises. 10. **Loss of Indicator Species**: Animals often serve as indicators of environmental health. Without them, it would be harder to detect problems early. Such a scenario would fundamentally change Earth's ecosystems and could have profound and largely negative impacts on the environment and human society.