...Marwan is not the son of shiekh Mohammed , he is adopted by shiekh Mohammed .
That is a gossip only. Full adoption of a foreign child (with name change of the adopted child) isn´t allowed in Islam. You know that. He never will be named as
Sheikh Marwan
bin Mohammed bin Rashid al Maktoum if he isn´t his son. In the case of raising an orphan, the child been named after his real father. There is the opportunity of taking care of him as a orphan only. That is and was a course of action in the Emirati society. But I think, this case is not very likely by Sheikh Marwan. He was born after the marriage with Sheikha Hind was started and Sheikh Mo already has other children (Manal, Hessa, Shamsa) with another unknown and Sheikha Hind. Sheikha Hind was pregnant with Sheikh Rashid when Sheikh Marwan was born. Sheikh Mo has received several children with different women (most of them are unofficial wives), which makes it more likely that Marwan is his biological son. In general many of the Sheikhs have had multiple wives and not all were always known at public. I know by Sheikh Marwan itself, that he is the son of Sheikh Mohammed and that his mother is German.
General backround information: Adoption was practiced by the Arabs before Islam. They gave the adopted child the name of the person from whom it was adopted as if it were his/her own child. Islam forbade the adoption, however, allowed the Muslims, children who were not their own to raise, care of them and give them support. But the children
must be named after their biological fathers. When looking at the issue of adoption from Islamic point of view, we must separate two things: first, the concept of helping orphan and poor children; second, the implications of such a help. As far as the concept of helping the poor and the orphan is concerned, Islam not only agrees to it but even highly recommends it. In all types of charities, the orphan and the poor are mentioned as the prime eligible recipients for such help.
Islam fully supports the concept of helping the orphan and poor, and taking them under your wings. If there is no one to take care of the orphan and poor children, then this responsibility falls upon the government. I won’t be wrong in saying that as far as the concept of adoption is concerned, there is no difference between Islam and the West. However, when we come to the implications and legal consequences of adoption, we find some differences between Islam and the present system in the West.
If a adoption took place in early infancy, then most probably the child will never come to know his real genealogy or his real family name. It is this part of the adoption procedure that Islam does not accept. In pre-Islamic Arabia, the adoption system was similar to what we now see in the West: the child even takes the family name of the adoptive father. When Islam came, it categorically rejected this procedure.
Abu Darr, may Allah be pleased with him, reported that he was the Prophet (PBUH) heard say: "There is no man this his membership explains to another expect for his father and it acts knowingly not the filed in faith with Allah. And who declares his belonging to people with whom he has no familial bond together, which is to take his seat in the Hellfire."
Both by Quran (33:4 "God did not make your adopted son as your own sons. To declare them so is your empty claim. God's word is righteous and constitutes true guidance." or look at 33:37-40) and the Hadith
adoption is strictly prohibited. The adoption affects the inheritance sequence that transfers title to the exclusion of the real heirs to a completely foreign person. Also the group among the possible marriage partners are excluded and will be blasted though adoption by men and women are brothers and sisters who are under islamic points of view not related. Furthermore, the marriage will be excluded with this persons, because the adoption is blocking the way to or vice versa. Means: that theoretically any person can married his own sister or her own brother unknowingly of their close family kinship. In summary: Adoption with acquisition of the name of the adopting family is forbidden in Islam.