  Here, we investigate how competition in the Eden model is affected by short
range dispersal and the requirement that site updates occur only after several
updates of the same site have been attempted previously. The latter models the
effect of tissue or media resistance to invasion. We found that the existence
of tissue intensifies 'Natural Selection' and de-accelerating 'Genetic Drift',
both to a limited extent. More interestingly, our results show that short-range
migration can eliminate Genetic demixing and conceal Natural Selection.
