Enormous and rapid loss of genetic diversity after intense breeding

Intense breeding of crops and livestock has resulted in enormous loss of genetic diversity

https://thesocietypages.org/socimages/2011/07/19/loss-of-genetic-diversity-in-u-s-food-crops/

Excerpt: "In his classic 1973 overview of U.S. agribusiness and its effects on the food we eat, Hard Tomatoes, Hard Times, Jim Hightower discusses how the search for market efficiencies had changed the tomatoes Americans could buy in their local supermarkets. Tomatoes posed a number of problems for modern industrial agriculture; in particular, they tended to get bruised or smashed when harvested by machine and transported long distances. To facilitate mechanical harvest and shipping, varieties were developed that were harder and tougher — often at the expense of other qualities, such as taste. This same process has occurred with many crops. For instance, I can buy huge, bright red strawberries year-round in the U.S. these days, as long as I don’t mind that they have only a hint of the rich taste of the strawberries my grandma used to grow.

As a result of concentration in agribusiness (including grocery chains) and selection of varieties that can withstand the mechanical harvesting and long-distance shipping required by the industrial food system, we see fewer and fewer varieties of crops on the shelf. Despite the efforts of heritage seed banks and heirloom variety enthusiasts, many have disappeared altogether; others are dangerously close to doing so. It’s an enormous loss of genetic diversity, of varieties that were developed over many years based on flavor, resistance to pests, ability to withstand drought, frosts, or other environmental stresses, and so on.

Dolores R. let us know that National Geographic posted an image based on a 1983 study by the Rural Advancement Foundation International that illustrates the loss of this genetic diversity. RAFI looked at a typical commercial seed catalog from 1903 — that is, a catalog of seeds targeting farmers producing for the market. They found a large number of varieties available. But then they looked at the seed collection at the National Seed Storage Laboratory (now the National Center for Genetic Resources Preservation). This government entity is in charge of collecting and storing seeds to preserve genetic diversity among crops and livestock. The bottom half of this image shows how many of the varieties in the 1903 catalog were in the lab’s collection as of 1983:

 

Of course, the NCGRP isn’t the only organization storing seeds; many private groups, such as Seed Savers Exchange, preserve heirloom varieties. And many varieties have been introduced, such as the Round-Up Ready crops developed by Monsanto to be compatible with Round-Up weed killer. The NCGRP has also added greatly to its collection over time. Nonetheless, many varieties have simply disappeared, reducing the genetic diversity available in our current agricultural system and increasing the risks should a virulent pest or disease attack the dominant varieties of crops and livestock. "

My comment: The more variation or adaptation, the more genetic degradation. This same phenomenon can be observed in nature and in artificially selected breeds of plants or animals. There is no mechanism for evolution.