Habitat loss and fragmentation: Destruction or alteration of natural habitats due to human activities like deforestation, urbanization, agriculture, and pollution leads to loss of essential resources for survival and ultimately extinction of species.
Climate change: Rapid changes in environmental conditions such as temperature, precipitation, sea levels, and acidity, caused by human-induced greenhouse gas emissions, can lead to the extinction of species that are not able to adapt or migrate quickly enough.
Overexploitation: Unsustainable hunting, fishing, or harvesting of species for food, fur, skin, or traditional medicine beyond their natural replacement rates can cause their populations to decline to unsustainable levels, leading to extinction.
Disease: Introduction of novel diseases or pathogens to a new population, either naturally or through human activities like transportation, can cause epidemics that can decimate susceptible populations and lead to extinction.
Invasive species: Non-native species introduced intentionally or accidentally to new environments can outcompete native species for resources, predation, or transmit diseases, leading to population decline and extinction of native species.
Co-extinction: The extinction of a species that has a close ecological relationship with another species, such as a pollinator or a host, can lead to the co-extinction of the dependent species.
Competition and predation: Inter-species competition for limited resources or vulnerability to predation can limit the survival of certain species, particularly if they experience changes in their ecological niches.
Genetic factors: Low genetic diversity within a species due to inbreeding or founder effects can make it more vulnerable to environmental changes or diseases, leading to population decline and potential extinction.
Natural disasters: Catastrophic events like volcanic eruptions, earthquakes, extreme weather conditions, or asteroid impacts can cause sudden and extensive loss of habitats, resulting in mass extinctions.
It's important to note that extinction is a natural phenomenon that has occurred throughout Earth's history. However, the current rate of extinction caused by human activities is significantly higher than the background extinction rate, posing serious ecological and biodiversity consequences.