She starts out by talking about evolution being a 'must' given variation, selection and heredity - and certainly this shouldn't be seen restricted to biological evolution (i.e. on the gene level). Memetics talks about a second type of replicator having taken its place in our world - the world of copyable ideas, 'living' and fighting for resources in our brains.
New replicators can be dangerous - as they 'care' only for themselves and can come into conflict with the goals of the substrate brains (think suicide memes in some religions for example).
She then brings on the ideas of a third type of replicator - technical memes, or temes, being memes which do not anymore depend on us - and use us to spread only in the sense that they (at least still at the moment) need us to create their infrastructure, e.g. the internet. In not too long a time these could get independent from us ... and for example the destruction of the environment would possibly be not important to them.
Two possible roads exist for her: we integrate with these temes (think cyborg), or they will do without us.
Next and finally she draws the arc to extraterrestrial life: looking at Drake's equation she proposes that it might be more important to look at replicators rather than intelligence and then the corresponding equation would contain in her view the probabilities for getting a first, second and third replicator anywhere - and surviving this process.