When I joined the Department of Genetics in the third year, I was fascinated to see how so much diversity is produced by combinations of only four letters, A, T, C and G, the four constituent bases of the DNA. The elegant mathematical equations of quantitative and population genetics provided a solid and a predictable framework to understand how simple genotypes can produce complex phenotypes, and how such a process can influence the changes of genotypes in time and space.

My graduation coincided with the inauguration of the new Bibliotheca Alexandrina in 2002. After participating in a competition there, I was selected to represent Egyptian Youth at the 2nd Earth Summit in Johannesburg, South Africa. It was an important experience for me. The genetic equations are not only relevant to understand the past and the origin of agricultural varieties, but they are also essential to predict the future and conserve the urgently depleting biodiversity. How could we conserve species from extinction if we do not understand how species are formed in the first place?

Back from the conference, I decided to pursue an academic career in population genetics. As the first-ranked of my promotion, I was given an assistant teacher position at the Department of Genetics in Alexandria. I asked my professors to conduct an M.Sc. thesis on population genetics, requesting to work on a marine organism. My mentor, Ahmed ElMetainy, suggested to me working on Drosophila, and I conducted a thesis under the supervision of his wife, Amira Abou-Youssef, on the population genetics of Drosophila in the oases of the Western Desert in Egypt. I owe to both of them my introduction to the Drosophila model, a model I kept working on for more than 20 years. 

The work on Drosophila population genetics in Egypt continued in the 1970s, studying allozyme variation, and in the 1980s, investigating the spread of P-elements. But by the 1990s, Drosophila studies have almost completely faded, replaced by molecular genetics and its biotechnological applications which were judged more appropriate to respond to the country’s needs. I was therefore lucky that my professors accepted to restart the work on Egyptian Drosophila in the early 2000s. Near Alexandria, I discovered the introduction in Egypt of two Afrotropical drosophilids in the country, namely Zaprionus indianus (a notorious fig pest) and Z. tuberculatus. The two invasive species are currently replacing both D. melanogaster and D. simulans. At that time, only a French laboratory at Gif-sur-Yvette was studying flies of the genus Zaprionus, and thanks to a bursary from the French Embassy, I conducted a 1-month training in this lab. Work on the two invasive Zaprionus has continued in Egypt under the leadership of Amira Abou-Youssef, and since 2019 I have renewed ties with Egyptian researchers to better understand the genomic basis of the adaptation of the two tropical species to the arid Egyptian environment and their potential impact on fruit production. 

It was thanks to these researchers that the Afrotropical origin of D. melanogaster was demonstrated, mostly due to the discovery of a number of closely-related species endemic to this region in the 1970s. This discovery bridged an important gap for the evolutionary history of the most genetically-investigated organism. Under the directory of Jean David in the 1980s, the laboratory centered its efforts on the species of the melanogaster subgroup making this clade a primary model in evolutionary genetics and speciation. The laboratory diversified its approaches from cytological and biochemical genetics to behavior and ecology. Following Jean David’s retirement, the lab became a center of molecular population genetics and diversified its study organisms beyond the Drosophila model, but the spirit of conducting evolutionary studies within an integrative framework of genetics, behavior and ecology remains as it is reflected in the laboratory current name.

Jean David is certainly the most influential scientific personality in my career. I joined his lab in 2004 and then as a PhD student (2005-2007). My PhD was on the systematics and ecological genetics of the genus Zaprionus that he was studying, especially in collaborations with Brazilian colleagues. I continued to collaborate with Jean during my subsequent postdoc years and got the privilege to conduct multiple drosophilid field collection trips in Africa with him and to learn as much from him in the field as well as in the laboratory. He was 87-year-old during our last mission on the island of Ngazidja (Grande Comore). Currently, different aspects of Drosophila evolutionary genetics including comparative genomics, evo-devo and behavioral ecology are maintained in the laboratory.