(Capcom's primary storyline)
Umbrella's t-Virus Project started off as a viral weapon that would ensure the infection and death of an entire target population. When this concept proved ecologically unsustainable, the mutating of organisms to serve as weapons that would kill survivors became the new target. The initial development of "Bio Organic Weapons" focused on simply infecting an animal and observing them for any beneficial properties. Among the initial projects was Neptune, which sought to create an enhanced aquatinc bio-weapon. The great white shark test subjects experienced only minor mutations and an increase in aggression. Another early B.O.W. test, Web Spinner, yielded better results in creating a 90 pounds (41 kg) spider able to run at 24 miles per hour (39 km/h). However, the lack of intelligence increase rendered it useless as a weapon.
With little success, the Arklay team continued their research and produced the β strain.