We humans are more alike than most of us realize

The almost two decades since scientists mapped the entire human genome have seen huge advances in a range of disciplines, from medicine to anthropology.

Researchers can now study genes to better predict the susceptibility of specific individuals and communities to inherited diseases, as well as satisfy people's curiosity about where they came from.

There has also been a commercial boom in the business of so-called home ancestry tests, in which customers provide a mouth swab to determine their ethnic origins. The MIT Technology Review found that as many people bought consumer DNA tests last year as in all previous years combined, with the total now at 26 million.

These commercial products come with a range of health warnings from experts and have sparked a lengthening list of controversies. Doctors and geneticists have described some tests as more parlor trick than medicine.

They say ancestry is not a sure guide to predisposition to any given diseases because most are not genetic. A visit to the doctor is probably a better bet than a commercial test.

Finding out about our long-lost ethnic origins might be intriguing but it too has its pitfalls.

In the United States, Democratic Party senator Elizabeth Warren took a DNA test to prove she was part-Native American, a claim that had been mocked by Republican rivals who said she was making it for political advantage.

It turned out she was right, even if the connection was as much as 10 generations in the past. However, Native American groups said Warren's ancestry did not mean she was part of a community with which she had no cultural connection.

Then, just this month, the entire genome of a young woman who lived in what is now Denmark 6,000 years ago was extracted from a piece of prehistoric "chewing gum." Scientists identified her diet and her ailments and established that she was dark skinned with blue eyes.

Similar research suggesting that ancient Scandinavians were dark-skinned has been denounced by online conspiracy theorists who claim it is part of a plot to rewrite Europe's "white" origins.

One glaring anomaly in genetic science since the complete genome sequence was published in 2003 is that most data has come from people of European origin.

Scientists say the under-representation of non-Europeans in human genetic studies has limited diversity in genomic datasets and led to reduced medical relevance for a large proportion of the world's population.

The international GenomeAsia 100K project aims to rectify that, having established a pilot program to enable genetic discoveries in 64 countries across Asia. The project has already sequenced some 600 genetic sets from across the continent, 70 of them from China.

The research will help scientists further identify traces of the extinct Denisovan species of humans among Asians, just as they have determined that modern Europeans are partly descended from ancient Neanderthals.

Apart from the medical advances that will ensue, the research will enable scientists to better establish the global movements of prehistoric populations and the relationships between them.

Modern science has helped to establish that the proportion of human genetic variation between populations is modest, and that individuals from different populations can be genetically more similar than individuals from the same population.

It has therefore replaced the Eurocentric pseudo-science of previous generations that fostered belief in a hierarchy of races, a doctrine that was not only erroneous but was also used to justify oppression and genocide.

Genetics has come to the conclusion that all humans are pretty much identical and that physical differences are literally skin deep.

Different populations were isolated from each other for millennia but global interchange in the past 500 years has been such that it is possible that everyone alive today has a common ancestor who was alive just a few thousand years ago.

It turns out that there is only one race: the human race.

One of the most intriguing findings was announced this month by the University of Barcelona where researchers found genetic evidence to back the theory that humans have evolved to be friendlier and more cooperative by selecting their companions depending on their behavior.

That is an encouraging thought at a time when nations that are still divided by language and culture, albeit to a diminishing extent in a globalized and connected world, face the same existential challenges, such as climate change.

As one team of researchers stated in 2004, the year after the human genome breakthrough: "No matter the languages we speak or the color of our skin, we share ancestors who planted rice on the banks of the Yangtze, who first domesticated horses on the steppes of the Ukraine, who hunted giant sloths in the forests of North and South America, and who labored to build the Great Pyramid of Khufu."

And within two thousand years, they concluded "it is likely that everyone on earth will be descended from most of us."