Livestock breed extinction is happening all over the world, and it is happening fast. For example, of the hundreds of native cattle breeds once raised in India, only a small fraction remain in significant numbers today. In several regions, dozens of local poultry breeds once thrived; now only a handful are commonly raised. Farmers in the past painstakingly bred and developed livestock well suited to the peculiarities of their local climate and fodder availability. In the recent past, heavy dependence on a few high-yielding breeds and industrial breeding programmes is causing the dwindling of genetic diversity in livestock. If some emerging disease or future climate shift devastates the few breeds we have come to depend on, we might desperately need some of the breeds we have let go extinct.

On the basis of the above passage, the following assumptions have been made:

1. Humans have been the main reason for the large-scale extinction of livestock breeds.

2. Raising locally adapted breeds ensures genetic diversity in livestock.

3. The present style of industrial breeding will finally lead to a livestock disease crisis in the near future.

4. Livestock disease resilience may depend on our ability to preserve locally adapted breeds.

Which of the above assumptions are valid?