It’s normal to cite your own work if the new paper is a continuation of that research. A references or three is normal and expected.
When somebody publishes a bullshit paper that is eventually withdrawn, every subsequent paper citing the fraudulent work can also be withdrawn as being unreliable.
A sign it’s all bullshit is when you see the majority of the citations for the paper from the same author. This usually doesn’t pass peer review anymore. In hyperspecialized fields with few researchers, they commonly get a little creative on the introduction section to include other authors.





There is a few different potential reasons as well as sexual preference.
Genetic incompatibility - the interspecific cross could only occur one way.
Genetic bottlenecks in the neandertal lineage. A high inbred coefficient could have decreased the neandertal females overall fertility (high deleterious alleles load). This could also cause a rapid reduction in the percentage of neandertal DNA in a mixed population.
Maternal behavior - Neandertals females might not have cared for hybrid offspring appropriately. This could be for anything from milk production requirements to differences in physiological developmental rates.