I would like to point out the entirety of the fossil record is lacking missing links.
While H. sapiens shows a variety of traits in a singular configuration, virtually every other species displays a simularity in phenotypic traits.
Neo-Darwinian evolution simply does not match the fossil record.
Species arise differentiated from their peers, and then persist unchanged for the duration of their existence.
Breeders of commercial species do not alter a gene, and then another, and then another, so on, until they finally arrive at the specific strain they desire.
They hybridize and then select from amongst the offspring, backbreeding them to their parent trees, one another, or other species.
This is how evolution actually occurs.
Read Eugene McCarthy on Stabilization Theory, and the fossil record suddenly makes sense, and alien intervention in terrestrial life seems less compelling, and unnecessary to explain H. sapiens origins.
That is not to say, either, that is necessarily false.

Thanks!