You can do a degree in various heritage related courses (archaeology, anthropology, museum/heritage studies, history of art, history and/or philosophy of science, and even many history courses, plus various regional studies courses, and related courses like classics, Egyptology, Ancient Near Eastern Studies etc) with your A-levels just fine. People go into those courses from all sorts of backgrounds.
I would note however the heritage and cultural/arts sector is challenging to get a foothold in - graduates usually end up paying a "passion tax" by having to accept lower paying roles for a while after graduating before they can move into more senior and curatorial positions. Also depending on the specific situation you may want or need to pursue a masters or PhD at some point in the process.
That said for "natural history" work in the museums sector you could well do a first degree in biological sciences and masters/PhD in some area of taxonomy and/or evolutionary biology/palaeontology (depending on your specific interests). This would require a scientific background at A-level (which you have) and is a bit of a different route. That said if your main interest is in human evolution you may find an archaeology and/or (biological/evolutionary/physical) anthropology degree closer aligned to that. Human sciences courses (the few that are around) may also facilitate an interest in human evolution.