Simplify the following text for a Grade 11 native English-speaking person.
Original: Ayman Muhammad Rabaie al-Zawahiri ( , ' ; born June 19 , 1951 ) is a prominent leader of al-Qaeda , and was the second and last `` emir '' of Egyptian Islamic Jihad , having succeeded Abbud al-Zummar in the latter role when Egyptian authorities sentenced al-Zummar to life imprisonment . While Al-Zawahiri is a reportedly a qualified surgeon , he has shown a deep and radical understanding of Islamic theology and Islamic history .
Simplified: Ayman al-Zawahiri ( born June 19 , 1951 ) is the deputy leader of al-Qaeda , and was the second and last 'em ir ' of Egyptian Islamic Jihad .