As another busy year draws to a close, we take a look back at the science stories and developments that have shaped 2016, bringing some momentous announcements with major advances from the direct detection of gravitational waves to the birth of a baby with DNA from three people.
The three-parent baby treatment, currently legal only in Britain, is taking its place in 2016's health news as a controversial one. With this technology, a child born following the procedure has DNA from two women and one man.
The world's first child conceived using the technology was born in Mexico earlier this year under the supervision of a U.S. medical team helping a Jordanian couple, New Scientist reported in September. The procedure, involves removing a tiny amount of faulty DNA from a mother's egg and replacing it with DNA from a second woman.
It is designed to prevent the transmission from mother to child of faulty genes in the mitochondria, the "batteries" that energize human cells and are inherited from the mother. Scientists believe that the procedure is a milestone in helping families to overcome mitochondrial disease.
AI beats human
In March, a computer program named AlphaGo defeated the Go world champion player, demonstration that computers can learn from experience.
AlphaGo won four games to South Korean Professional player Lee Sedol's one in their Go matchup. Developed by Google subsidiary DeepMind, the program made history in 2015 by becoming the first machine to beat a human pro player, but 33-year-old Lee, one of the world's top players, was seen as a much more formidable opponent.
Go, most popular in countries such as China, South Korea and Japan, involves two contestants moving black and white stones across a square grid, aiming to seize the most territory.
It is perfect for artificial intelligence research because there are many moves for a machine to win by brute-force calculations, the route IBM's Deep Blue used to famously beat former world chess champion Garry Kasparov in 1997. Until AlphaGo's victory last year, experts had not expected an artificial intelligence program to beat a human professional for at least a decade.
A global threat: Zika virus
A two-month-old baby diagnosed with the Zika virus in Puerto Rico.
The photos showing mothers posing with their babies who had been diagnosed with microcephaly linked to the Zika virus in Brazil are presumably some of the most heartbreaking scenes 2016 has seen. Having become an alarming global health problem after a major outbreak in Brazil, active Zika outbreaks have been reported in more than 60 countries or territories, most of them in the Americas. In February, the World Health Organization (WHO) declared an emergency over Zika alhough it broke out in 2015. Zika is transmitted to people through the bite of infected female mosquitoes, primarily the Aedes aegypti mosquito, the same type that spreads dengue, chikungunya and yellow fever. Aedes aegypti mosquitoes are found in all countries in the Americas except Canada and continental Chile. The WHO said the "most likely explanation" is that Zika virus infection during pregnancy is a cause of congenital brain abnormalities including microcephaly. Brazil has confirmed more than 2,200 cases of microcephaly believed to be linked to Zika infections in pregnant women. There is no treatment for the Zika infection. Scientists are racing to develop a safe and effective vaccine, but a preventative shot is not expected to be ready for widespread use for at least two or three years.
Still way to go to cure depression
So far natural depression treatments like physical activity, changing lifestyle and the way of thinking are common non-drug options to keep your mental health as good as possible. According to the WHO an estimated 350 million people of all ages suffer from depression world-wide. In September, a group of Turkish scientists from Uludağ University said "Glycyl-glutamine," an endogenous dipeptide synthesized from beta-endorphin, can be used for depression treatment. In a previous study, the research team has found that Glycyl-glutamine increases serotonin hormone levels. Clinical trials will continue for the TÜBİTAK-funded project.
The origin of dogs
The long-debated question of where dogs first appeared has always been complex, and a study published in June by the journal Science suggests it may have two answers.
Dogs arose from the domestication of wolves, and the work suggests this happened twice, once in Asia and also in either Europe or the Near East.
The study drew on genetics and archaeological records. It included a complete genome from a dog that lived in Ireland about 4,800 years ago and more limited DNA from 59 European dogs that lived 14,000 to 3,000 years ago. The ancient DNA was compared to genetic data for 685 modern dogs.
The complex analysis led to this proposed scenario: Dogs arose from wolves in Asia and from a different wolf population in Europe or the Near East. Then, the Asian dogs traveled west along with humans. They arrived on the turf of the other dogs between about 6,000 and 14,000 years ago and partially replaced them or interbred with them, establishing a new population that is genetically different from Asian dogs.
The ground-breaking detection of gravitational waves that was announced in February is the next biggest science story of 2016. The researchers said they detected gravitational waves that washed over Earth after two distant black holes spiraled toward each other and merged into a single, larger abyss 1.4 billion years ago.
It created a scientific sensation and was a benchmark in physics and astronomy, transforming a quirky implication of Einstein's 1916 theory of gravity, saying massive objects warp space-time around them into the realm of observational astronomy. According to New Scientist, their presence was inferred in 1974, but none had been observed directly - until now.
NASA's Jupiter Mission
This year's exciting space news story comes from NASA scientists in July as the Juno probe had successfully entered the orbit of the biggest planet in our solar system. "We're there. We're in orbit. We conquered Jupiter," lead mission scientist Scott Bolton, with the Southwest Research Institute in San Antonio, told reporters. NASA's Juno spacecraft capped a five-year journey to Jupiter with a do-or-die engine born to sling itself into orbit, setting the stage for a 20-month dance around the biggest planet in the solar system to learn how and where it formed. Jupiter orbits five times farther from the sun than Earth, but it may have started out elsewhere and migrated, jostling its smaller sibling planets as it moved.