Table 4.

Example of spatiotemporal controllability assessment for hypothetical experimental field trials of GE gene drive olive flies in Spain ^a

Biology of the target species	Interactions with the environment	Intended biological characteristics of the GE organism
Olive flies are a wild species that can persist and propagate in the Mediterranean area and in regions with a similar climate. Their habitat is not clearly confined, except for the presence of olive trees (Nardi et al. 2005; Daane and Johnson 2010). Under specific conditions, such as high population densities, maximum dispersal distances for olive flies range from 4000 to 5000 m (Remund et al. 1976; Economopoulos et al. 1978).	There are complex interactions with other species such as birds, spiders, ants, chalcid wasps, and symbiotic bacteria (Neuenschwander et al. 1983; Bigler et al. 1986; Daane and Johnson 2010; Gonçalves et al. 2012; Picchi et al. 2016). The interrelationships include grazing, predation, and symbiosis. The interrelations vary greatly throughout the life history of the flies and different developmental stages (egg, larva, pupa, adult).	The trait is unlikely to enhance fitness; however, the gene drive is capable of spreading through wild olive fly populations, resulting in female lethality but fertile male offspring that further propagate the drive.
Population dynamics and life cycle go through several stages (egg, larva, pupa, adult) and are subjected to winter seasons, creating potential bottlenecks in regional populations (Ochando and Reyes 2000; Augustinos et al. 2005).	There are specific and symbiotic microbes associated with the olive flies (Capuzzo 2005; Ben‐Yosef et al. 2014).	Once released, the GE flies will mate in natural populations and cause the emergence of next generations without human intervention. Next generation effects might occur without being noticed.
Molecular analyses indicate a high level of gene flow among the Mediterranean populations (Ochando and Reyes 2000; Augustinos et al. 2005; Segura et al. 2008).		If the population is suppressed to a certain degree, it may be assumed that, depending on the amount and frequency of GE flies released, they might be eliminated after a period of time. However, various factors can have an impact on these processes, and their actual duration cannot be determined.
There are other known species that can mate with olive flies. However, it is unclear whether they can produce viable offspring and enable gene flow (Schutze et al. 2013).

GE = genetically engineered.

^a Vertical reading; aspects in each row are not specifically linked to each other; each column stands alone.