I am referring to both their culture and their ancestry. To be neutral, I'll ask the same of Israelis in another post.
Lots of claims fly around about them being descendent from very recent migrations from surrounding regions, or thousands of years ago in the Arab Islamic conquest, or that they're the same people that have always been there since pre-history, they simply assimilated into a new culture. What do you historians say about the claims, I want to sources and data. Please and thank you.
Edit: I am specifically referring to the demographic and population history of the southern Levant, particularly the group of people who identify as Palestinian and/or Arab. I wish to avoid the politics concerning names and territorial claims.
This isn't a historical source, but purely in terms of population genetics, there have definitely been studies done. Take a look here for a Jewish population genetics study. Even if you don't have access, there is a chart that is visible to the public, Fig. 2, which shows the Fixation index (Fst) for various populations. The Palestinians and Druze are roughly as closely related to Ashkenazi Jews as they are to Egyptians. Yemeni Jews are the closest relatives to Palestinians.
European Jewish populations are related to broad European populations, while Middle Eastern Jewish populations are related to broad Middle Eastern populations (while sharing great similarities with each other), which is extremely unsurprising considering the events in these regions. While many Jews migrated away from Judea/Palestine, many also stayed, with some maintaining their Judaism and Jewish identity through to the Ottoman empire and beyond, while others converted to Christianity or Islam and assimilated into other cultural identities over time. We also know that during the Ottoman Empire some European Jews did migrate to the Ottoman Empire after, for instance, being expelled from Spain or Portugal, so the movement of the Diaspora was not as straight forward as it may seem.
Followup:
What has separated Palestinians from other Arabs in the Middle East, other than name and location?
Would one be tell the difference between a Palestinian and a Syrian, for example, whether it be by accent, mannerisms, etc.?