What is the difference between tribal and primal?

tribe
noun
1. a social division in a traditional society consisting of families or communities linked by social, economic, religious, or blood ties, with a common culture and dialect, typically having a recognized leader.
"indigenous Indian tribes"
synonyms: ethnic group, people, band, nation; More
2. BIOLOGY
a taxonomic category that ranks above genus and below family or subfamily, usually ending in -ini (in zoology) or -eae (in botany).

trib·al
adjective
1. of or characteristic of a tribe or tribes.
"tribal people in Malaysia"
noun
1. members of tribal communities, especially in South Asia.

prime1
adjective
1. of first importance; main.
"her prime concern is the well-being of the patient"
synonyms: main, chief, key, primary, central, principal, foremost, first, most important, paramount, major; More
2. of the best possible quality; excellent.
"a prime site in the center of Indianapolis"
synonyms: top-quality, top, best, first-class, first-rate, grade A, superior, supreme, choice, select, finest, top-end, top-tier; More

noun
1. a state or time of greatest strength, vigor, or success in a person's life.
"you're in the prime of life"
synonyms: heyday, best days, best years, prime of one's life; More
2. CHRISTIAN CHURCH
a service forming part of the Divine Office, traditionally said (or chanted) at the first hour of the day (i.e., 6 a.m.), but now little used.

pri·mal
adjective
1. relating to an early stage in evolutionary development; primeval.
"primal hunting societies"
synonyms: original, initial, earliest, first, primitive, primeval
"the primal source of living things"
2. essential; fundamental.
"rivers were the primal highways of life"
synonyms: basic, fundamental, essential, elemental, vital, central, intrinsic, inherent
"primal masculine instincts"

All from google.com
As for difference, they are not comparable. One refers to membership, the other to time.