The evolution of a poisonous snail species from an ancestral snail species that was not poisonous can be explained by the phenomenon of trait gain.
Evolution is the process of slow and gradual changes that occur within a species. It is long-term process that takes over millions of years and various generation for the change to be visible. Evolution can be caused by the environmental factors or genetic factors or both.
Trait gain is the phenomenon of evolution where a species can evolve a trait that was not present in their ancestors. This evolution can take place to either to combat any unfavorable situation or to protect oneself from the enemies around.
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