1. The remains of 13 Neanderthals in El Sidrón Cave, Spain, suggest that they were mating with their close kin.
2. DNA tests from the bones indicate that inbreeding and a small population size were likely factors contributing to physical peculiarities in this family.
3. Inbreeding has occurred throughout human history, especially in royal families, and was likely due to small population size and low population density.
The article is generally reliable and trustworthy as it provides evidence for its claims through multiple sources such as scientific studies, research papers, news articles, etc. The article also presents both sides of the argument equally by providing evidence for both interbreeding between Neanderthals and modern humans as well as inbreeding within the same family group. Furthermore, the article does not present any promotional content or partiality towards any particular point of view.
However, there are some potential biases present in the article which could be explored further. For example, while the article mentions that inbreeding has occurred throughout human history due to small population size and low population density, it does not explore other possible reasons for why this might have happened such as cultural practices or religious beliefs. Additionally, while the article mentions that rare harmful traits tend to be amplified if close kin interbreed, it does not provide any evidence or examples of this happening among Neanderthals or other ancient hominins.
In conclusion, overall the article is reliable and trustworthy but could benefit from exploring some potential biases further and providing more evidence for its claims regarding rare harmful traits being amplified through inbreeding among ancient hominins.