Modern zoos are often involved in breeding programmes to promote genetic diversity, however, due to the small number of animals available for breeding in captivity, there is a small gene pool resulting in offspring that are not very genetically diverse. This can cause problems in the future as the species have low genetic diversity, and can be more susceptible to extinction through disease and environmental change. This can cause an inability to release these animals into the wild as the original parents of these organisms were captured and brought into captivity long ago. By 2000 most animals in zoos were offspring of other zoo animals. Arguably these offspring have lost the ability to survive in the wild because of the lifestyle their ancestors have lived in captivity, without having to migrate, hunt for food or survive attack from predators. Modern zoos need to re-evaluate the need for breeding programmes, and the manner in which they are carried out, with the effectiveness compared to the huge monetary and ethical costs. The ease of introducing the organisms back into the wild needs to be reassessed too, due to the limited success, especially of large mammals in the past, perhaps due to the distance of the breeding programmes from the original habitat where the organism needs to be re-introduced too. This could be because the length and stress of travel to a completely new habitat means the organism cannot adapt, and is therefore unable to survive. The use of international studbooks has improved the sharing of information regarding captive breeding programmes and has ensured that the gene pool is as large as possible, however it is arguably not perfect due to pledges from zoos to stop capturing wild animals to enhance the gene pool.
Overall ex-situ conservation measures should support in-situ conservation measures because in-situ conservation should be the primary objective. This is because the maintenance of the original habitat, and involvement of indigenous people and governments can often help improve the outcome of the conservation projects and can often lead to better success, due to the local knowledge of species. Zoos need to fix their morality issues, the effectiveness of breeding programmes and the laws and guidelines to become more involved in conservation efforts and further protect the world species.
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