Study Suggest Genetic Connection to Same-sex Behavior, But Not to Genes

 

A large study suggests that genes² are connected to homosexual behavior, but also found there is no gene¹ that makes people gay.

The study is said to be the largest of its kind. Researchers examined genetic³ material and information about sexual experiences from more than 470,000 adults in the United States and Britain. The findings were published in Science magazine.

The researchers found there are thousands of genetic differences linked to same-sex sexual behavior. Most have a very small effect on a person's behavior.

However, the researchers said five of the genetic markers were more strongly linked with same-sex sexual behavior. The genetic differences, or variants⁴, were more commonly found in people who reported having had a experience at some time.

Some of the genetic variants found were present in both men and women. Two of the variants found in men were near genes involved in male hair loss and sense of smell.

About five percent of British participants and about 19 percent of U.S. persons who took part reported ever having a same-sex sexual experience. Those providing information for the study were not asked whether they identified themselves as gay or lesbian.

The research “provides the clearest glimpse yet” into the genetic reasons for same-sex sexual behavior, said study co-writer Benjamin Neale. He is a geneticist at the Broad Institute in Cambridge, Massachusetts.

But Neale also added, “We also found that it’s effectively impossible to predict an individual’s sexual behavior from their genome.”

The researchers noted⁵ that the study centered on people’s sexual behavior, and not on sexual identity. They also noted that the study only involved people whose ancestors were European. They could not answer whether similar results would be found in other groups.

The origins of same-sex behavior are unclear. Some of the strongest evidence of a genetic link comes from studies on twins. Many scientists believe that social, cultural, family and biological conditions are also involved. Some religious groups and other critics consider it a choice or a behavior that can be changed.

A Science magazine commentary notes that the five identified genetic variants had such a weak effect on behavior that using the results “for prediction, intervention⁶ or a supposed ‘cure’ is wholly...impossible.”

Experts not involved in the study had many reactions. Former National Institutes of Health geneticist Dean Hamer said the study confirms “that sexuality is complex and there are a lot of genes involved.” But he added that the study was not “really about gay people.”

“Having just a single same sex experience is completely different than actually being gay or lesbian,” Hamer noted.

His research in the 1990s linked a marker on the X chromosome⁷ with male homosexuality. Later studies had similar results. The latest study, however, found no such link.

Doug Vanderlaan is a psychologist at the University of Toronto in Canada. He said the lack of information on sexual orientation⁸ is a weakness of the study.

The study was released on August 29. An international team of experts from Britain, the U.S., Europe and Australia carried out the research. They completed human genome examinations using blood samples from the UK Biobank and saliva⁹ samples from the U.S.-based ancestry¹⁰ company 23andMe. All samples were from individuals who had agreed to take part in the research.

I’m Anna Mateo.

Words in This Story

homosexual –adj. a person sexually attracted to people of the same sex

gay –adj. describing a homosexual person

participant –n. a person who is involved in an activity, event or study

lesbian –n. a woman who is sexually attracted to women

glimpse –n. a brief or quick view or look

origin –n. the point or place where something starts

twin –n. either one of two babies who are born at the same time to the same mother

sample –n. a small amount of something that give information about what it was taken from

1 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

2 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

3 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

4 variants   

n.变体( variant的名词复数 )；变种；变型；（词等的）变体

参考例句：

• Those variants will be preserved in the'struggle for existence". 这些变异将在“生存竞争”中被保留下来。 来自辞典例句
• Like organisms, viruses have variants, generally called strains. 与其他生物一样，病毒也有变种，一般称之为株系。 来自辞典例句

5 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

6 intervention   

n.介入，干涉，干预

参考例句：

• The government's intervention in this dispute will not help.政府对这场争论的干预不会起作用。
• Many people felt he would be hostile to the idea of foreign intervention.许多人觉得他会反对外来干预。

7 chromosome   

n.染色体

参考例句：

• Chromosome material with exhibits of such behaviour is called heterochromatin.表现这种现象的染色体物质叫做异染色质。
• A segment of the chromosome may become lost,resulting in a deletion.染色体的一个片段可能会丢失，结果产生染色体的缺失。

8 orientation   

n.方向，目标；熟悉，适应，情况介绍

参考例句：

• Children need some orientation when they go to school.小孩子上学时需要适应。
• The traveller found his orientation with the aid of a good map.旅行者借助一幅好地图得知自己的方向。

9 saliva   

n.唾液，口水

参考例句：

• He wiped a dribble of saliva from his chin.他擦掉了下巴上的几滴口水。
• Saliva dribbled from the baby's mouth.唾液从婴儿的嘴里流了出来。

10 ancestry   

n.祖先，家世

参考例句：

• Their ancestry settled the land in 1856.他们的祖辈1856年在这块土地上定居下来。
• He is an American of French ancestry.他是法国血统的美国人。