[61a top]: R’ Shimon bar Yochei: Only the Jewish people are called ADAM.
Olos Ephraim: There are four words in Tanach used to reference “man:” איש, גבר, אדם, & אנוש (Ish, Gever, Enosh, & Adam). All of them appear in the plural form as well as: אישים, גברים, & אנשים except for אדם (Adam), which has no plural form. The reason that the Jewish people are referred to by “Adam” is specifically because of its singularity. Jews have unity like no other nation on earth [ie: when one Jew is in danger the whole world comes together to recite Tehillim (psalms)].
D-E-ep Thoughts: We are the nation of “one man with one heart.” We must learn to come together for the good times as well as the bad. When we recognize our intimate connection with our fellow Jews it is so much easier to want to give of ourselves for others. Just as a husband and wife complete one soul, so too the Jewish nation on a whole makes up one complete body. We all need to function together to produce common goals, put our selfish egocentric focuses aside, and produce the most beautiful harmonic symphonies to fill the world with G-d’s glorious music.