Interestingly, this expression has been utilized in connection with the creation of 'insan'… وَ لَقَدْ خَلَقْنَا الإِِنْسَانَ مِنْ صَلْصَالٍ مِنْ حَمَإٍاءٍ مَسْـنُونٍ “And certainly We created man of clay that gives forth sound, of black mud fashioned in shape.” [^2] as well as for 'bashar'… وَ إِذْ قَـالَ رَبُّكَ لِلْمَلاَئِكَةِ إِنِّي خَالِــقٌ بَشَراً مِنْ صَلْصَالٍ مِنْ حَمَإٍاءٍ مَسْـنُونٍ “And when your Lord said to the angels: Surely I am going to create a mortal of the essence of black mud fashioned in shape.” [^3] And later, also for Adam (a.s.) - this being inferred contextually from the mention of the prostration of the angels (Note the verses 29, 30 and 31 of Suratul Hijr.) At first glance, the apparent meaning of the verse appears to be that initially Adam (a.s.) was created out of black mud and then, when his form was completed, the divine soul was blown into it subsequent to which the angels fell down in prostration before him, except Iblis.
The style of speech indicates that between the creation of Adam (a.s.) from mud and the emergence of the present form no other species existed.
The term 'ثـم', appearing in some of the verses and used in the 'Arabic language to denote 'a sequence with intervening time intervals', can never be taken as evidence to claim the passage of millions of years and the existence of thousands of species; rather, it could quite possibly allude to the intervals that existed between the various stages of Adam's (a.s.) creation - from mud and then from dry clay and then the blowing of the divine soul.
And it is for this reason that this very term 'ثـم' has been employed in connection with the creation of man in the embryonic world and the stages of his development within it.