Editing Halibut (section)

=== Evolutionary diversification of fragmented populations ===
In the Atlantic halibut studies have shown that the Atlantic Continental Shelf stock and the Gulf of St. Lawrence stock have begun to differentiate genetically from each other due to low connectivity between populations, low rates of exchange, and subsequent adaptation to local environments. Some adaptations can show up as changes in life-history trait parameters, which can change on a faster time scale than evolution and cause behavioural segregation. This can occur even in areas with enough genetic mixing to prevent genetic divergence.<ref name="Shackell-2022" /><ref name="Kess" /> One small but significant observed adaptation difference in the Atlantic halibut has been that the fish in the warmer Scotian Shelf have a faster growth rate than the halibut in the colder southern Grand Banks.<ref name="Shackell-2022" /> The Pacific halibut population remains largely genetically homologous throughout their range, but there is some variation of life-history traits on a geographic gradient.<ref name="Shackell-2022" /> Despite its large range, the populations of Greenland halibut remain largely homogenous due to a lack of barriers for gene flow between its four major populations.<ref name="Wojtasik-2021" /> There are small differences between subpopulations due to differing environmental factors, such as salinity and temperature gradients, but not to the degree seen in Atlantic halibut, as gene flow and migration continues throughout many different stocks.