Public health scientists and professionals have human health and welfare at the center of our concerns. But we have learned that the human species is part of a tightly connected web of other living species and we are all roaming around in a common environment, the surface of the earth. Avian influenza is a good case in point. The influenza virus is mainly a parasite of birds but some forms also infect humans and some infect both. The influenza/A subtype designated H5N1 (“bird flu”) is a case in point. It devastates terrestrial birds, like poultry, and when it infects humans it has a truly horrific case fatality ratio, Ebola-like in magnitude and effect. But it’s not just the effect of the virus on us that is of public health concern. Poultry is one of the major sources of affordable protein throughout the world (including the US), and when you wipe out a poultry industry you have a major effect on nutrition. One of the major concerns about Genetically Modified crops is that the monopoly of seed stocks by large companies like Monsanto will lead to monoculture, a severely restricted genetic diversity that might make entire crops vulnerable to a disease adapted to a prevalent genetic make-up. It turns out that a team of experts from the US, China, The Netherlands and Canada have the same worries about the poultry “crop”:
As concerns such as avian flu, animal welfare and consumer preferences impact the poultry industry, the reduced genetic diversity of commercial bird breeds increases their vulnerability and the industry’s ability to adapt, according to a genetics expert.
Purdue University animal sciences professor Bill Muir was part of an international research team that analyzed the genetic lines of commercial chickens used to produce meat and eggs around the world. Researchers found that commercial birds are missing more than half of the genetic diversity native to the species, possibly leaving them vulnerable to new diseases and raising questions about their long-term sustainability.
“Just what is missing is hard to determine,” Muir said. “But recent concerns over avian flu point to the need to ensure that even rare traits, such as those associated with disease resistance, are not totally missing in commercial flocks.” (The Poultrysite)
This work was made possible because the entire chicken genome was published in 2004, the first bird to have its entire genome sequenced. In diploid organisms like chickens and humans, the genes are paired and the elements of the pair, the alleles, may differ somewhat or be the same. If they are identical there is no variation in that allele. According to the research team, commercial chickens have lost 90% of their alleles in comparison to native and non-commecial birds.
This is the same problem as the monoculture worry in non-animal crops. The standardization and drive for efficiency characteristic of industrial production has consequences.