by Jake Meyer

The internet revolutionized every facet of our lives – work, play, and even our relationships.  With the invention of the internet came numerous matchmaking sites that helped two people find each other for a relationship or marriage.  Match.com allows users to browse through personally created profiles and contact each other, while Eharmony.com matches users based on a test that covers "29 dimensions."  But how is the biotechnology revolution changing relationships?  And how will these technologies alter how we view love and marriage?

One way the biotechnology revolution is changing marriage is through the screening of potential mates to see whether they both carry the genes of a particular disease.  This way the potential mates know whether their children would be more likely to be born with a particular disease and can then make informed decisions about procreation.  For example, in the Ultra-Orthodox Jewish community of New York, where arranged marriages among Ashkenazim (Jews of Eastern European descent) are still common, match makers screen potential matches for a genetic disease known as Tay-Sachs.

People who are of Ashkenazi descent have a one-in-25 chance of having a Tay–Sachs genetic mutation; if two such carriers marry, each child has a one-in-four chance of having the devastating disease.  A child with Tay–Sachs appears normal at birth, but soon loses motor functions, suffers massive neurological deterioration has seizures, and generally dies by age three.  To prevent couples having children with this devastating genetic disease an organization known as Chevra Dor Yeshorim (Association of an Upright Generation) offers Tay–Sachs carrier screening to Ultra-Orthodox Jewish adolescents.  Before a marriage is arranged, the matchmaker calls the program with the identification numbers of the two individuals.  If both individuals are carriers for Tay-Sachs, they are found to be "genetically incompatible."  The program has added screening for other disorders, such as cystic fibrosis, which has generated controversy because these diseases are not necessarily fatal in childhood.

But what about using genetic screening on a mate not to determine whether they carry the genes for a disease, but instead to discover whether mates are genetically compatible?  GenePartner.com does just that –- setting up couples based on genes that would make the couple more naturally attractive to each other.  According to the GenePartner website, the GenePartner project was inspired by a study by Dr. Claus Wedekind at the University of Bern in Switzerland.  Wedekind had female volunteers smell T-shirts that had been worn by men for three consecutive days and then rate the smell of the T-shirts for attractiveness.  Wedekind then analyzed the part of the DNA of the men and women that codes for HLA (human leukocyte antigen) molecules.  HLA molecules control the activation of immunological effectors during an immune response, making them essential for immune resistance.  Wedekind found that the women were most attracted to men with HLA DNA different from their own.  According to GenePartner.com compatible couples have different HLA DNA, leading to varied HLA molecules that allow immunity to a wider variety of diseases.  GenePartner.com also claims that this "gene compatibility" also results in an increased likelihood of forming an enduring and successful relationship, more satisfying sex life, and higher fertility rates.

And so now with the help of genetics you’ve found your genetic compatible mate –- someone with a differing HLA gene and sweaty T-shirts you find irresistible –- but what can genetics do to make the relationship last?  Well perhaps with a little help from genetics you could give your mate a drug — a love potion of sorts — or alter their genes to make them more monogamous.  Dr. Larry Young has studied prairie voles, one of the five percent of mammals that, like humans, are monogamous.  A hormone in the voles, vasopressin, creates urges for bonding and nesting when it is injected in male voles.  Male voles with a genetic mutation that caused a weaker vasopressin response were less likely to find mates.  The same thing has been found in humans as well –- Swedish researchers have reported that human males with a genetically caused weak vasopressin response were also less likely to find a mate.

Armed with this knowledge, it’s possible that we could engineer our mates and ourselves to have a stronger vasopressin response and in turn be more monogamous.  Or if an individual or society decided that monogamy was not desirable, we could engineer ourselves to have less of a vasopressin response.

So as you look in to the eyes of your significant other this Valentine's day, you may find yourself wondering whether you should both get genetic testing, or whether you find his sweaty T-shirt attractive, or if he's more like a vole or more like the 95% of other mammals in the world.  At this point you may realize that genetics (and the internet) have made you think about love and relationships just a bit differently.