The major causes of biodiversity loss primarily involve the negative impacts human activities have on ecosystems, with some of the most critical factors being:

• Overexploitation: This refers to the unsustainable use of wildlife and plant species for food, medicine, or other human needs which leads to the reduction in numbers of these species to dangerously low levels.
• Co-extinction: This occurs when the extinction of one species leads to the extinction of another species that depend on it for survival, such as a predator and its prey or a plant and its pollinator.
• Habitat loss and fragmentation: This is the process whereby a large, continuous area of habitat is both reduced in area and divided into smaller, more isolated fragments due to activities like logging, agriculture, and urban development. This disrupts ecosystems and decreases the viability of populations.

Regarding the listed options:

• Mutation: While mutations (genetic changes) are not generally a direct cause of biodiversity loss, they can influence the adaptability and survival of species. However, they are not typically regarded as a major driver of biodiversity loss.
• Migration: Normal species migrations are natural phenomena and not a direct cause of biodiversity loss. Instead, barriers to migration created by human activities can contribute to biodiversity loss by preventing species from reaching essential habitats for their survival and reproduction.

Therefore, the correct option that lists recognized major causes of biodiversity loss is:

Option D: A, B, and D only (Overexploitation, Co-extinction, and Habitat loss and fragmentation).