In Brief

Homosexuality and bonding.  Morality is the choice between different types of conduct, between right and wrong. Why, in the minds of the Supreme Court justices, is heterosexuality right and homosexuality wrong?

Homosexuality is an evolutionary whipsaw.  According to Darwin, favorable characteristics that enhance an organism’s survival are passed on to the next generation, contributing to the species’ evolution.  Homosexuality is at odds with Darwinian evolution.   Single-sex unions are fruitless.  Without reproduction between the two genders, the human species will not survive.  Absent other benefits, at least superficially, it would be expected that homosexuality would be selected against.  By legislating against homosexuality, the state is effectively codifying a law of nature.  Was the Bowers court acting out of morality or biology?

While homosexual behavior is not procreatively functional, it may have other social purposes.  L.M. Fendigan, studying a group of monkeys who showed high levels of homosexual behavior in which females, during mating season, solicits partners of both sexes, consorting and mounting both male and female monkeys.  She writes: “[W]e found that females who had engaged in homosexual consorts during the mating season were likely to remain affinity bonded (friends) throughout the year in contrast to male-female consort pairs which were not translated into year-long bonds.  Since sexual partners are almost always unrelated, these friendships cross-cut matrilineal lines and are potential source of alliance and bonding in addition to kin ties.”  Primate Paradigms, by L.M. Fendigan, The University of Chicago Press, 1992, Page 143.

Is there a genetic basis for homosexuality?  A gene called “fruitless” was identified in fruit flies in the 1970’s that influences sexual preference.  Males with the gene mutation are unable to discriminate between the sexes, engaging both male and female flies in courtship behaviors.  Males with severe mutations in fruitless lose interest in sex altogether.  When confronted with cues that elicit sexual behavior in normal males, fruitless males fail to follow female flies, play courtship songs on their wings, or attempt copulation.  The fruitless gene codes for a protein expressed in fruit fly brain cells that plays a role in turning other genes on and off.  Scientists suggest that it coordinates male sexual behavior.  Roush, Science, 274:1836, 1996; Ryner et al., Cell, 1079, 1996.In human genetics, the discovery of a “gay” gene has been more elusive.  On the basis of twin studies, psychologists have suggested that there is a genetic basis for homosexuality.   One published investigation reported that 54% of the identical twins of gay men were also gay, compared to only 22% for fraternal twins.  The first hint of a human gay gene that could account for these observations was a study in 1993 of families with a high incidence of gay relatives.  Researchers found that a certain DNA signpost on the Xq28 region of the X chromosome was correlated with male homosexuality.  Males in the family who had inherited an X chromosome from their mother bearing this signpost were more likely to be gay than their male relatives who had not. This led to the suggestion that a gay gene was on the X chromosome.  Since the publication of this work, other groups have been unable to repeat it, making the gay gene controversial, but not dead.  The original researchers still stick by their data.  Wickelgren, Science, 284: 571 (1999); Rice et al., Science, 284:665-667 (1999).

Same-sex marriage has been determined by one state court to be constitutionally required.  In December 1990, three couples applied for a marriage license from Hawaii’s Department of Health: Ninia Baehr and Genora Dancel, Tammy Rodrigues and Antoinette Pregil, and Patrick Lagon and Joseph Melillo.  The Department of Health (“DOH”) declined to issue a marriage license to the couples solely on the grounds that the couples were of the same sex.  The Hawaii Marriage Law which set forth the requirements for a valid marriage contract referred to the man and woman to be married.  Since the couples were of the same sex, the Hawaii DOH considered them incapable of forming a valid marital union under Hawaii law.  The couples sued the DOH.  On appeal to the Hawaii State Supreme Court, the court ruled that the U.S. Constitution did not guarantee the couples a fundamental right to same-sex marriages. “[W]e do not believe that a right to same-sex marriage is so rooted in the traditions and collective conscience of out people that failure to recognize it would violate the fundamental principles of liberty and justice that lie at the base of our civil and political institutions.  Neither do we believe that a right to same-sex marriage is implicit in the concept of ordered liberty, such that neither liberty not justice would exist if it were sacrificed.”  Baehr v. Lewin, 852 F.2d 44 (Hawaii 1993) at 57.

However, in a striking decision, the court found the Hawaii Marriage Law violated the Equal Protection Clause of the Hawaii Constitution, which guaranteed all citizens, irrespective of sex, the equal protection of the laws.  Because the Hawaii Marriage Law established a sex-based classification, the Court held that it must be reviewed under the “strict scrutiny”  standard.  The court remanded the case to circuit court to consider under this standard whether (1) the state’s sex-based classification was justified by a compelling state interest; and (2) the statute was narrowly drawn to avoid unnecessary abridgement of the couple’s constitutional rights.  On retrial, the circuit court ruled in favor of the couples, finding that the Hawaii Marriage Law unconstitutional, and that the state cannot deny marriage licenses to same-sex couples solely because of their sex.  Baehr v. Miike, Civil. No. 91-1394 (1st Circuit, Hawaii 1996).  The case was appealed to the Hawaii State Supreme Court, but in 1999, the court dismissed the appeal as moot in view of a 1998 amendment to the Hawaii constitution that gave lawmakers the authority to limit state-recognized marriages to opposite-sex couples.

In response to the Hawaii case, preemptive legislation was set off throughout the nation. At least 30 states banned gay marriages, and Congress passed the Defense of Marriage Act, which denied federal recognition of homosexual marriage and allowed states to ignore same-sex unions licensed elsewhere.

Same-sex marriages.  In July 2000, Vermont gave gay and lesbian couples the right to join in civil unions, a status equivalent to marriage. Since then, nearly 1,000 couples have obtained licenses and have gone to see a minister or judge.  The Vermont civil union law resulted from the December 1999 Vermont state Supreme Court holding that the state constitution entitles same-sex couples to “the common benefits and protections that flow from marriage under Vermont law.” Baker v. State, 744 A.2d 864 (Vt. 1999).   The court wrote extending legal protection to a same-sex couple’s commitment to a lasting relationship “is simply, when all is said and done, a recognition of our common humanity.” The court did not give same-sex couples the right to marry. Instead, it ordered the Legislature to pass a law providing equivalent rights. If the Legislature had failed to pass such a law, the court would simply extend marriage rights, it said.  

Why does the law prohibit marriage between kin?  Under the Hawaii Marriage Law, HRS §572-1:  “In order to make valid the marriage contract, it shall be necessary that: (1) The respective parties do not stand in relation to each other of ancestor or descendent of any degree whatsoever, brother and sister of the half as to the whole blood, uncle and niece, aunt and nephew, whether the relationship is legitimate or illegitimate.”

The main benefit of sex is recombination.  It leads to offspring that are genetically different from the parents and from each other.  Genetic diversity is advantageous because it provides the variation necessary for individuals to adapt to the environment.  For instance, it has been proposed that the best defense to parasites is genetic diversity.  A population runs the risk of dying out when confronted with a lethal or debilitating parasite epidemic.  Differences between individual members of the population -polymorphisms - which lead to parasite resistance in some members, but not others, can effectively rescue the population from extinction.  J. Seger and W.D. Hamilton in The Evolution of Sex, R.E. Michod and B.R. Levin, eds., Sinauer Associates, Inc., 1988. 

The environment acts on the population in the same way.  Picture the individual differences or phenotypes expressed by population members as a menu and the external factor, be it a parasite or an environmental condition, acting on the population as a diner.   The more menu items the diner has to chose from, the more likely it is that the diner will be able to satisfy his appetite.

How does recombination give rise to diversity?  It happens in a couple of ways. Humans have 23 chromosome pairs for a total of 46 chromosomes in each body cell.  One member of the pair is from the mother and the other is from the father.  Reproductive cells, called gametes, however, contain half the number of chromosomes found in normal body cells.  Each gamete – such as a sperm or egg – has 23 chromosomes, one chromosome for each of the 23 pairs.  The gametes are formed in a process called “meiosis” in which a cell, having the normal number of 46, splits to give rise to cells having 23 chromosomes.  The chromosomal pairs assort independently of each other.  As a result, even though each gamete has 23 chromosomes, the particular chromosomes present will differ from gamete to gamete.  At one extreme is a gamete having all 23 maternal chromosomes or all 23 paternal chromosomes.  In practice, gametes have a mix of both maternal and paternal chromosomes.  This means that offspring will inherit different genetic material, a source of variation between siblings. 

There is yet another variation generating mechanism.  During one part of meiosis, the individual chromosomes in the chromosomal pairs get close together and wrap around each other, often swapping small pieces in process called “crossing-over,” so that at its end individual chromosomes are chimeric.  The specific string of genetic instructions on the original chromosome is no longer intact but has been broken up and exchanged with its matching pair.  Chromosomes which have experienced crossing-over contain pieces of both the maternal and paternal chromosomes. 

The combination of chromosomes inherited by an offspring when the gametes of two parents combine through sexual reproduction is another source of diversity. When two unrelated individuals sexually reproduce, they create a unique combination of chromosomes, resulting in an individual having different sets of traits and characteristics.

What happens when two siblings reproduce?  A unique individual is produced but selected from a smaller pool of genes than when unrelated organisms reproduce.  Normally, offspring get only one copy of their genes from each parent.  Suppose each sibling has inherited a deleterious gene from its mother.  The deleterious gene is “recessive,” which is to say that in the presence of its normal counterpart the gene’s effect is masked; however, when an individual gets two bad copies, the gene’s deleterious effect is expressed in the individual.  When the two siblings reproduce, there is a chance that each will contribute the “bad” gene to one offspring, resulting in a child that has two copies of the bad gene and therefore feels its effect.  Thus, reproduction between related individuals can result in bad genes being doubled in offspring. 

The problem with this argument is that the same would be true for a “good” gene.  Half the progeny might suffer but the other half would benefit.  A more plausible explanation is that there is simply more diversity generated when unrelated individuals reproduce.  Siblings are selecting from the same pools of gene, so that their progeny will share many of the same genes.  To maximize diversity is a population, reproduction between unrelated individuals - called “out-crossing” - should be encouraged.  This is especially true in small communities where the gene pool from which to select is small. By having a law prohibiting the marriage between certain kin, this biological principle is reinforced.