Notsureifsrs, but i'll bite.
Almost all these 'ancient astronaut' beliefs stem from the work of an author named Erich von Däniken who wrote on the subject matter sometime in the 60s. His work was comprised of bad archaeology and his own interpretations of what he believes to be evidence of extraterrestrial activity by ancient civilizations. He's gotten some more air time in recent years since History Channel realized their demographic was single, middle-aged white males going through midlife crisis so a lot of this 'Ancient Astronaut' malarky has picked up steam again.
One of the more humorous claims of the video was the genetic mutation argument that went something like this:
1. Great Apes (which includes humans) have 48 chromosomes with the exception of humans, who have 46.
2. Chromosome 2 is fused, giving us giving us 23 pairs of chromosomes instead of 24.
3. Therefore, aliens.
Here's the thing: Yes, our chromosome 2 is the only thing separating us from from the rest of the Great Apes, making our genomes around 99.x% identical. However, to claim that it was somehow aliens that caused this without any evidence to support it, is simply absurd. The only evidence he even put forth was that it couldn't have happened in nature, which is in itself another unsupported claim. Without getting too sciency, mutations and chromosome fusions occur during DNA recombination while in meiosis.
There are far too many assumptions and presuppositions for me to take this seriously.