In considering the content of these sentences and the intention of the writer, it is important to ensure that emphasis is placed appropriately and personalizing the issue (using "us") should be avoided as it reduces the effect. This ensures that the reader is, in this case, sufficiently warned of the dangers of going beyond previously inconceivable limits and furthermore, what the implications are for mankind as a whole. Depending on whether your main focus is mankind's enslavement or the initial crossing of boundaries, the following are possible options:
1. Transgressing unnatural boundaries may lead to unnatural places and events as the brothers have warned. To her detriment, Dolly the Sheep will be expressed as nothing more than an invention of artificial intelligence which, in the scheme of things, will lead mankind to complete enslavement.
2. There is a danger that the complete enslavement of mankind may result from having cloned Dolly the Sheep who is expressed as nothing more than the invention of artificial intelligence. The brothers have warned that unnatural transgressions such as this can only lead to unnatural circumstances in the whole scheme of things.