As a new beekeeper, I never really considered much about the origins of honey bees. I knew they were not native to the United States, most are from Europe and the ones that sting in a swarm are called Africanized. Local beekeepers talk about ordering Italians or Carniolans to populate hives, and during a recent local beekeeper’s association presentation, Asian honey bees were mentioned. From where Apis mellifera, the Western honey bee arose, I did not know.
As it turns out, the origin of honey bees is a highly debated topic. Some say they arose from Asia; others say Africa. Recently, researchers from the University of California—Davis used short nucleotide polymorphisms (SNPs) and two sets of previously published whole genome data, included additional sequenced genomes and applied multiple computational methods to analyze honey bee population genetics. They published their conclusions in Genome Biology and Evolution. Continue reading “From Whence You Came, Honey Bee?”
The ability for adults to digest the milk sugar, lactose, is often referred to as lactase persistence (LP), describing the continued (persistent) production of lactase into adulthood. LP is an autosomal dominant trait that is most often associated with a T allele situated 13,910 base pairs (–13,910*T allele) upstream of the lactase gene, LCT. Archaeogenetic data indicates that pre- and early Neolithic populations were largely LP-negative, and that the frequency of the LP phenotype rose dramatically in Europe around 8,000 years ago, coinciding with the Neolithic transition from a hunter-gather to an agricultural-based lifestyle (1) and the appearance of domesticated dairying animals. Today roughly 35% of adults are lactose persistent. The frequency varies dramatically by geographic region, from a high prevalence in Europe (89–90%) and to a relatively low prevalence in the eastern Mediterranean (15%)(1). The spread of lactase persistence is an often cited example of gene-culture co-evolution. You can’t separate the history of domestic dairying and the evolution of lactase persistence, but scientists are still trying to understand how these two worked together. Continue reading “What Came First: LP or the Cow? Genetic and Cultural Co-evolution of Lactase Persistence and Dairying”
If you are of a certain age, the name “Tasmanian Devil” most likely conjures up an image of a ferocious brown hairy cartoon character that traveled in the center of a tornado of chaos. Sometimes, as in this case, the truth is much less strange than the fiction. The real Tasmanian Devils (Sarcphilus harrisii) are relatively small, somewhat cuddly looking, marsupials found only on the island of… you guessed it, Tasmania. Despite their diminutive size, they are the largest living carnivorous marsupial. Unfortunately, these terrier-sized animals are also in danger of becoming extinct, largely as a result of a deadly, infectious transmissible cancer called Devil Facial Tumor Disease (DFTD). Continue reading “The Devil is in the Details: Genetic Diversity and the Endangered Tasmanian Devil”
The genetics of wild cheetah (Acinonyx jubatus) populations has a special significance for me. In fact, it could be said that the population genetics of cheetahs changed my life. I first learned about the low genetic variability in cheetahs in a darkened lecture hall at Iowa State University in 1988. I was so fascinated by what I learned in those lectures about genetics and its importance in conservation efforts that I eventually changed my major to Genetics. “The Cheetah Papers” as a colleague calls them, were, and perhaps still are, common teaching tools for biology and genetics classes. And why not? The results were amazingly cool, if a bit disturbing. Imagine a population that, through a series of natural events over thousands of years, had become so genetically similar to one another as to be almost clonal.
It is sad but true that the latest news has not been promising for wild tiger populations. In September, an article published in PLoS Biology (1) estimated that the best hope of saving the wild tiger population would be to shift focus to source sites, which are “…at spatially well-defined priority sites, supported by proven best practices of law enforcement, wildlife management, and scientific monitoring.” The authors estimate the cost to save these sites at $82 million (U.S). At the time of publication, $47 million had been committed by governments and other groups. It isn’t difficult math to figure out there is a deficit. Continue reading “The Latest On: When Five Hundred Tigers Are Not Enough”