missing link
ape-man

At the press conference the fossil was described as the "missing link" in human evolution.

Reference Number 4 is no longer valid (missing link).

The Clock could be considered the "missing link" between pulp and comic book heroes.

It was billed as being the "missing link" in photography.

Intelligence agencies are constantly looking for the "missing link".

The idea of a "missing link" between humans and so-called "lower" animals remains lodged in the public imagination.

When the other seven bridges are eventually constructed, the "missing link" will open up a stretch of road 16.1 miles (25.9 km) long.

Hagfish research has found the "missing link" in the evolution of the eye.

The exhibit was intended as an example of the "missing link" between the orangutan and white man.

This, in my opinion, is the great missing link in the research on cancer and blood type.