I was going to post this in response to the top level post that was claiming Palestinians 'came from Arabs', but thankfully that post was diligently removed. It was done so before I could post this refuting literature, but I believe you will find the article to be useful regardless.

Abstract:

The genetic profile of Palestinians has, for the first time, been studied by using human leukocyte antigen (HLA) gene variability and haplotypes. The comparison with other Mediterranean populations by using neighbor-joining dendrograms and correspondence analyses reveal that Palestinians are genetically very close to Jews and other Middle East populations, including Turks (Anatolians), Lebanese, Egyptians, Armenians and Iranians. Archaeologic and genetic data support that both Jews and Palestinians came from the ancient Canaanites, who extensively mixed with Egyptians, Mesopotamian and Anatolian peoples in ancient times. Thus, PalestinianJewish rivalry is based in cultural and religious, but not in genetic, differences. The relatively close relatedness of both Jews and Palestinians to western Mediterranean populations reflects the continuous circum-Mediterranean cultural and gene flow that have occurred in prehistoric and historic times. This flow overtly contradicts the demic diffusion model of western Mediterranean populations substitution by agriculturalists coming from the Middle East in the Mesolithic-Neolithic transition.

Human Immunology 62, 889-900 (2001). ã American Society for Histocompatibility and Immunogenetics, 2001. Published by Elsevier Sciece Inc.

This area has historically belonged to the Sea PeoplesCanaanites or Phoenicians, also known as the land where the sea Peoples settled timeline, Philistines, and/or Phoenicians map

National Geographic on the Phoenicians

For one, they want to know whether mysterious groups known as the Sea Peoples might have migrated into Lebanon around 1200 b.c. and mixed with the Canaanites to help create Phoenician culture. Although the Sea Peoples, who may have come from the Aegean, marauded and burned most of the major cities along the coast of the Levant, they apparently spared the Canaanite cities. One leading Phoenician scholar, Maria Eugenia Aubet of Pompeu Fabra University in Barcelona, believes the Canaanites made a deal with the Sea Peoples.

However, modern day Lebanon and Syria are also credited with the Phoenicians.

http://en.wikipedia.org/wiki/Philistines

These are the people of Tyre and Carthage.

Around since after the fall of Troy.