User:Ttbioclass/Halibut

Outline
Tyler, this is an excellent outline - it really helps me be able to give detailed feedback at this stage. I think all the topics you touch on seem very interesting and clearly connected to evolution. I would combine the species and physical descriptions in the same location, as they touch on very related material. I will suggest some rearrangements below as well.Evol&#38;Glass (talk) 20:48, 4 October 2022 (UTC)

Species

 * 1) List of species and locations
 * 2) This will contain a list of the halibut species and where they are naturally located in the world.
 * 3) Differences among species
 * 4) This will describe physical and genetic differences among the species of halibut.

Genetics
I'd skip the first part about how genetics is used in determining evolutionary distance, and instead focus on how they are related to one another (and perhaps put that in the first section)Evol&#38;Glass (talk)
 * 1) Use in determining evolutionary distance
 * 2) This will describe the process of using the DNA of a halibut to determine its species and the species genetic closeness to other species.

I think I would put the sex determining genes in its own section. It is a good idea to talk about how sex is determined, and whether that varies across species. Some of this you will be able to condense when you write your draft, too Evol&#38;Glass (talk) 20:48, 4 October 2022 (UTC)
 * 1) Evolution of Sex Determining Genes
 * 2) Possible genes and chromosomes
 * 3) This will describe the possible genes responsible for new systems of sex determination in the halibut and what chromosomes they are expected to be on.
 * 4) Differences among species
 * 5) This will describe differences in sex determination genes between halibut species.

Physical Characteristics

 * 1) This will describe the size, weight, and coloring of the halibut.

Diet

 * 1) This will describe what types of animals the halibut eat and where they find them.

Halibut Fishery
I'm looking forward to reading this section! Perhaps label as "impacts of fisheries on halibut" or something indicative of what you are specifcally discussing here (the alternative would be to have one big title, and then smaller titles where you deal with the effectsEvol&#38;Glass (talk) 20:48, 4 October 2022 (UTC)
 * 1) Individual fishing quotas
 * 2) This will describe the individual fishing quota system that is given out to vessels that are fishery participants during the fishing season.
 * 3) Fishing impact on division of populations
 * 4) Atlantic Halibut
 * 5) This will describe the separation of the Atlantic Halibut into separate populations due to fishing
 * 6) Greenland Halibut
 * 7) Migration
 * 8) This will describe the migration of the Greenland Halibut across the Atlantic Ocean.

As Food
You might want to cut this out, unless you are really psyched to write about it (or put in 1 sentence in the start of the fishery section that talks about why they are farmed/fished Evol&#38;Glass (talk) 20:48, 4 October 2022 (UTC)
 * 1) Nutrition
 * 2) This will describe the nutritional facts of raw halibut meat and cooked halibut meat.
 * 3) Food preparation
 * 4) This will describe how halibut is prepared to be eaten, historical methods of preparation, and issues with preparation.

Other species sometimes called “halibut”

 * 1) This will list species that are not halibut but are sometimes referred to as halibut.

Sex Determining Genes
Halibut species vary in sex determination systems. The Atlantic Halibut went down a purely XX/XY route, with the male being heterogametic, around 0.9 to 3.8 million years ago. The sex determining gene for the Atlantic Halibut is likely to be gsdf on chromosome 13. The Pacific Halibut went down a ZZ/ZW route, with the female being heterogametic, around 4.5 million years ago. . The master sex determining gene of the Pacific Halibut is located on chromosome 9 and it is likely to be bmpr1ba. The gene sox2 is likely to play the same role in the Greenland Halibut.

Halibut Fisheries
(note: there are other sections in the fisheries part in the Halibut article)

Overfishing and Population Decline
The Atlantic Halibut has been a major target of fishing since the 1840's with overfishing causing the depletion of the species in the Georges Bank in 1850, then all the way up to the Canadian Arctic in 1866. In the 1940's the American fishing industry collapsed but the Canadian fishing industry remained, until there was a decline in Canadian Halibut fishery in the 1970's and 1980's. This allowed the Halibut population to briefly rebound before collapsing in the 1990's. Since a low point in the early 2000's the population has rebounded once again and may be stabilizing, but the species is not nearly as abundant in most locations as it was in the early 1800's.

Atlantic Halibut Population
Currently Atlantic Halibut is managed as two stocks in Canadian waters, which are the Atlantic Continental Shelf stock and the Gulf of St. Lawrence stock. The Atlantic Halibut has two other stocks in the Northwest Atlantic, those being the Gulf of Maine-Georges Bank stock controlled by the United States and one controlled by France near the Saint-Pierre and Miquelon Archipelago. The Georges Bank stock is still considered to be depleted and it is listed as a species of concern in the United States. In the two main populations of Atlantic Halibut there are many subpopulations, but many have been lost due to patches of extreme overfishing and the populations remain depleted as a whole from what they were in the 1800s.

Pacific and Greenland Populations
The Pacific Halibut and Greenland Halibut have not had this level of fragmentation, and their population is far larger in the United States' waters, with North Pacific Halibut and groundfish fisheries extracting the largest volume of catch out of all United States fishery areas. Sometimes the California Halibut is mistaken for a subspecies, but they are not, and are not even a true Halibut species. In the North Atlantic, observation of migration indicates that there are only two major populations of Greenland Halibut that both stretch vast distances. Those populations being the Northeast one stretching from the Kara Sea to Greenland, and the Northwest one stretching from Newfoundland to Baffin Bay. These stocks had been previously thought to be four different populations, but migration has indicated that they are only two different populations, and that fishing has not fragmented them. New research also indicates that the Greenland halibut originally came from the Pacific Ocean and spread into the Arctic Basin when the Bering Strait opened for a second time around 3 million years ago, and thus the Pacific halibut is its closest living relative.

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 of life-history trait parameters, which can change on a faster time scale than evolution and cause behavioral segregation. This can occur even in areas with enough genetic mixing to prevent genetic divergence. 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. The Pacific Halibut population remains largely genetically homogeneous throughout their range, but there is some variation of life-history traits on a geographic gradient. Despite its large range, the populations of Greenland Halibut remain largely homogeneous due to a lack of barriers for gene flow between its four major populations. 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.