Does evolution sometimes have to pass through intermediate forms of low fitness?

But before brains can become large enough to model the universe they must develop from intermediate forms.

However, intermediate forms are often found, and they may represent the same species.

There are sometimes intermediate forms between the two species, making them difficult to distinguish.

In these situations many species appear to grade into one another, and intermediate forms are common.

There is also an intermediate form with milky yellow spots.

Between these two extremes are any number of intermediate forms.

But we are in a straitjacket, having to accept one or the other, when often some intermediate form would be better.

Several times before, a splitting up has been attempted, but there were always too many intermediate forms.

He also has an intermediate form, of which I know little.