Neanderthals had an outsize effect on human biology.
Geege Schuman stashed this in Genetics
Using de-identified genome data and medical records from 28,000 hospital patients, Simonti and Capra looked for differences in traits and medical diagnoses between people with a particular Neanderthal gene variant and those with the H. sapiens version of the same gene. They found that the Neanderthal variants seemed to slightly increase the risk of conditions such as osteoporosis, blood-coagulation disorders and nicotine addiction. Another analysis, which looked at the combined effects of many DNA variants, painted a more mixed picture. It revealed links between Neanderthal DNA and depression, obesity and certain skin disorders, with some variants being associated with an increased risk and others with a reduced risk. Simonti presented the data at the annual meeting of the Society for Molecular Biology and Evolution in Vienna on 15 July.
So basically we are Neanderthals with slightly different DNA.