Flies have been around for at least 250 million years, surviving global warming and freezing and major "extinction events" such as that which wiped out the dinosaurs. Yet we know surprisingly little about this constant and frequently irritating companion to man and animal life.
In an attempt to rectify this, Australian scientists have joined a global effort to map the genetic structure and evolutionary history of the fly which could also entail a major rethink of Darwinian principles. One of them, David Yeates, an entomologist, describes the task as "an incredibly important project considering flies comprise about 10 percent of animal life forms on the planet."
Yeates and John Oakshott, a molecular biologist, are directing a US$2.4 million grant from America's National Science Foundation for Australian participation in the study, which also includes US, Canadian and Singaporean teams. Their job is to bring together field research in the coming fly-ridden Australian summer and recover the fossil records going back millions of years of flies preserved in amber, shale and ancient layers of marine sediments.
ILLUSTRATION: MOUNTAIN PEOPLE
"It is difficult but not impossible to recover data from flies that have been dead for a few hundred million years," Yeates says.
"In some cases, they left behind hard casings or exo-skeletal remains, and in others we even see internal organs containing traces of DNA. With very well preserved flies or those we catch alive, electron microscopy is yielding detail that would have eluded scrutiny until recent advances in medical or forensic technology," he says.
A favorite saying of Yeates is that "a big part of biodiversity is actually `flyodiversity.' Of nearly 2 million living species known to science, and with many more yet to be identified, around one-tenth are flies or `diptera' of some sort," he adds.
Diptera, a large order of insects having a single pair of wings and a sucking or piercing mouthpart, includes flies, mosquitoes, gnats and midges.
Yeates estimates there are up to 40,000 distinct species of flies in Australia alone, although only 8,000 of them have been scientifically described and named. When the five-year international project is completed it expects to have grouped between 200,000 to 400,000 types of flies into at least 150 distinct families.
"There are major practical implications from knowing our flies better," Yeates says. "They have been around for at least 250 million years, appearing well before the dinosaurs and surviving periods of global warming, global freezing and major extinction events that saw many species, including the dinosaurs, cut down at the seeming height of their powers. So we know that by studying their genetic make-up we may learn more about their capacity to adapt to shocks that destroyed other life forms."
But the benefit of mapping fly DNA goes much further, because the fly genome has enough in common with the human genome to help decode the more complex genetic makeup of mankind. Being simpler, it is also much better understood in species like the common brown fly found everywhere except in the most extreme southern polar environments.
"When we see something unknown in the human genome we can often get clues to its purpose by computer matching a similar genetic structure in a type of fly where that particular molecular combination already has a known function," Yeates says.
Oakshott's major role in the project is to examine the genes that are making some modern flies resistant to the pesticides used in agriculture. Finding out whether those genes have lain dormant for aeons before being "turned on" by a dose of fly spray, or evolved as an instantaneous defense mechanism in flies in the last 100 years is one of the biggest riddles in the study of evolution.
"This is a crucial question because it is asked of all species of animal," Yeates says. "If we discover that the environmental stresses caused by the rise of humans can cause the instantaneous origination of new species of flies then a lot of things that are accepted about evolution will need revision."
Already the world's farms -- where pesticide-resistant flies are breeding better than those that didn't adapt -- are looking like a case study from journals of the 19th century naturalist Charles Darwin, who first described the evolution of species as a coherent scientific theory.
The Australian part of the fly study will be incorporated in a National Science Foundation "Tree of Life" electronic databank and a web site run by the US Department of Agriculture in Washington.
"This is where the continuing practical benefits of the work will become apparent," Yeates says. "It means there will be an open source of information available for use by agricultural or medical researchers, where the answers to their questions may have been buzzing around their heads without being recognized."
Chinese President Xi Jinping (習近平) has created a dilemma that could soon cause him to be hoisted with his own petard, bringing his leadership of China to an end. His threatening rhetoric over the unification of Taiwan with China, in which he has said, “we are willing to draw blood if necessary,” has placed Xi in a corner. Xi is portrayed as a strong world leader, yet he has created a scenario for himself that most likely would have an unfavorable outcome. With the 20th National Congress of the Chinese Communist Party (CCP) scheduled to convene this month, Xi cannot
The 77th session of the UN General Assembly opened on Sept. 13. More than 10 overseas Taiwanese organizations had submitted a petition to the UN secretary-general, protesting that 23.5 million Taiwanese are excluded from representation. As president of the Taiwan United Nations Alliance, I also submitted a letter to the UN, saying that Taiwanese should have the right to be represented under the name of Taiwan. The government has been asking its allies to support Taiwan’s entry into the UN, but under its official name, the Republic of China (ROC). Doing so would have involved the right to represent China, with
I was privileged to meet with many of Taiwan’s leaders and leading thinkers during a study tour visit in August. One theme I heard several times during that trip was that bad relations between the United States and China benefit Taiwan. At first thought, I empathize with the argument. After all, there is a troubling record of America’s leaders negotiating with Beijing over the heads of Taiwan’s leaders. For example, President Franklin Delano Roosevelt returned Taiwan to China after World War II. President Richard Nixon surprised Taiwan leaders with his 1972 trip to China. President Jimmy Carter unilaterally chose to normalize
Washington’s “one China” policy has not changed and the US does not take a position on Taiwan’s sovereignty issue, a US Department of State spokesperson has said. He said that this has been the principle of US policy toward Taiwan since 1979, and the policy has remained in effect. He also said that US Secretary of State Antony Blinken has privately made this clear to Chinese Minister of Foreign Affairs Wang Yi (王毅). The US’ “one China” policy and China’s “one China” principle recognize China as the “representative of China.” The two diverge on the issue of Taiwan: Beijing asserts sovereignty