"Roots: One Year Later," the ABC anniversary special on WJLA-7 at 8 tonight, just makes the viewer yearn for the original. In its review of the impact the eight evenings of "Roots" had last January the best moments are clips from last year.

Louis Gossett Jr., who won an Emmy for his portrayal of the Fiddler, narrates the show, often using unnecessary hyperbole. Though the views of some actors, producer David L. Wolper and a sociologist are included, the hour locuses on Alex Haley.

Haley hobnobs with Johnny Carson, receives humorous praise from President Jimmy Carter at a Congressional Black Caucus dinner last fall, and, survives the crush of autograph seekers. Haley looks admirably uncomfortable throughout much of this whislwind, except for three instances: his family's trip to Juffure, the village of his ancestor, Kunta Kinte, in the West African country of the Gambia; walking around his family home in Henning, Tenn., and talking to his grandson, the ninth generation of Kunta Kite.

Most of the scenes in tonight's program dealing directly with the impact of "Roots" seem to stretch the point, or make the wrong one. Do we need to see a baby named after Kunta, in the hospital nursery? Do we need the same scene with Gossett and LeVar Burton, dubbed in Spanish, French and Japanese, to illustrate the global impact?

Missing are some of the more critical events connected with "Roots." The accusation that Haley's griot was a fraud and the plagarism lawsuit, filed by author Margaret Walker Alexander Haley has not ignored these controversies but handled them in a straightforward manner.

As Haley walks down a street in Henning, he ends the show with one of his favorite quotes from his grandmother, who said, "The Lord might not come when you expect Him to, but He will always come on time." Maybe, next year "Roots: The Next Hundred Years," a dramatic sequel, will come on time and keep the real dynamics of the original alive.