If this is true of the individual, as nobody denies, why should we consider it derogatory to human dignity to admit a similar development for the species?
This is a very different thing from claiming that man is descended from a monkey.
The human embryo may at one time resemble a fish with gill-slits and tail, but it is not a fish.

It is a human embryo.

So the human species( 38) may at various stages of its long development have resembled to the outward eye various species of lower animals, but it was still the human species, possessing the mysterious latent power of developing into man as we know him today, nay more, of developing in the future, we trust, into something far higher still.
'Abdu'l-Baha says:-- ...

it is clear that this terrestrial globe in its present form did not come into existence all at once; but ...

gradually passed through different phases until it became adorned with its present perfection....
...