An invention that could change the internet for ever

[yunowu]

Revolutionary new web software could put giants such as Google in the shade when it comes out later this month. Andrew Johnson reports


The biggest internet revolution for a generation will be unveiled this month with the launch of software that will understand questions and give specific, tailored answers in a way that the web has never managed before.

The new system, Wolfram Alpha, showcased at Harvard University in the US last week, takes the first step towards what many consider to be the internet's Holy Grail – a global store of information that understands and responds to ordinary language in the same way a person does.

Although the system is still new, it has already produced massive interest and excitement among technology pundits and internet watchers.

Computer experts believe the new search engine will be an evolutionary leap in the development of the internet. Nova Spivack, an internet and computer expert, said that Wolfram Alpha could prove just as important as Google. "It is really impressive and significant," he wrote. "In fact it may be as important for the web (and the world) as Google, but for a different purpose.

Tom Simpson, of the blog Convergenceofeverything.com, said: "What are the wider implications exactly? A new paradigm for using computers and the web? Probably. Emerging artificial intelligence and a step towards a self-organising internet? Possibly... I think this could be big."

Wolfram Alpha will not only give a straight answer to questions such as "how high is Mount Everest?", but it will also produce a neat page of related information – all properly sourced – such as geographical location and nearby towns, and other mountains, complete with graphs and charts.

The real innovation, however, is in its ability to work things out "on the fly", according to its British inventor, Dr Stephen Wolfram. If you ask it to compare the height of Mount Everest to the length of the Golden Gate Bridge, it will tell you. Or ask what the weather was like in London on the day John F Kennedy was assassinated, it will cross-check and provide the answer. Ask it about D sharp major, it will play the scale. Type in "10 flips for four heads" and it will guess that you need to know the probability of coin-tossing. If you want to know when the next solar eclipse over Chicago is, or the exact current location of the International Space Station, it can work it out.

Dr Wolfram, an award-winning physicist who is based in America, added that the information is "curated", meaning it is assessed first by experts. This means that the weaknesses of sites such as Wikipedia, where doubts are cast on the information because anyone can contribute, are taken out. It is based on his best-selling Mathematica software, a standard tool for scientists, engineers and academics for crunching complex maths.

"I've wanted to make the knowledge we've accumulated in our civilisation computable," he said last week. "I was not sure it was possible. I'm a little surprised it worked out so well."

Dr Wolfram, 49, who was educated at Eton and had completed his PhD in particle physics by the time he was 20, added that the launch of Wolfram Alpha later this month would be just the beginning of the project.

"It will understand what you are talking about," he said. "We are just at the beginning. I think we've got a reasonable start on 90 per cent of the shelves in a typical reference library."

The engine, which will be free to use, works by drawing on the knowledge on the internet, as well as private databases. Dr Wolfram said he expected that about 1,000 people would be needed to keep its databases updated with the latest discoveries and information.

He also added that he would not go down the road of storing information on ordinary people, although he was aware that others might use the technology to do so.

Wolfram Alpha has been designed with professionals and academics in mind, so its grasp of popular culture is, at the moment, comparatively poor. The term "50 Cent" caused "absolute horror" in tests, for example, because it confused a discussion on currency with the American rap artist. For this reason alone it is unlikely to provide an immediate threat to Google, which is working on a similar type of search engine, a version of which it launched last week.

"We have a certain amount of popular culture information," Dr Wolfram said. "In some senses popular culture information is much more shallowly computable, so we can find out who's related to who and how tall people are. I fully expect we will have lots of popular culture information. There are linguistic horrors because if you put in books and music a lot of the names clash with other concepts."

He added that to help with that Wolfram Alpha would be using Wikipedia's popularity index to decide what users were likely to be interested in.

With Google now one of the world's top brands, worth $100bn, Wolfram Alpha has the potential to become one of the biggest names on the planet.

Dr Wolfram, however, did not rule out working with Google in the future, as well as Wikipedia. "We're working to partner with all possible organisations that make sense," he said. "Search, narrative, news are complementary to what we have. Hopefully there will be some great synergies."

What the experts say

"For those of us tired of hundreds of pages of results that do not really have a lot to do with what we are trying to find out, Wolfram Alpha may be what we have been waiting for."

Michael W Jones, Tech.blorge.com

"If it is not gobbled up by one of the industry superpowers, his company may well grow to become one of them in a small number of years, with most of us setting our default browser to be Wolfram Alpha."

Doug Lenat, Semanticuniverse.com

"It's like plugging into an electric brain."

Matt Marshall, Venturebeat.com

"This is like a Holy Grail... the ability to look inside data sources that can't easily be crawled and provide answers from them."

Danny Sullivan, editor-in-chief of searchengineland.com

Worldwide network: A brief history of the internet

1969 The internet is created by the US Department of Defense with the networking of computers at UCLA and the Stanford Research Institute.

1979 The British Post Office uses the technology to create the first international computer networks.

1980 Bill Gates's deal to put a Microsoft Operating System on IBM's computers paves the way for almost universal computer ownership.

1984 Apple launches the first successful 'modern' computer interface using graphics to represent files and folders, drop-down menus and, crucially, mouse control.

1989 Tim Berners-Lee creates the world wide web – using browsers, pages and links to make communication on the internet simple.

1996 Google begins as a research project at Stanford University. The company is formally founded two years later by Sergey Brin and Larry Page.

2009 Dr Stephen Wolfram launches Wolfram Alpha.
http://www.independent.co.uk/life-style/gadgets-and-tech/news/an-invention-that-could-change-the-internet-for-ever-1678109.html

[yunowu]

Kevin Lafferty is a smart, cautious, thoughtful scientist who doesn't hate cats, but he has put forth a provocative theory that suggests that a clever cat parasite may alter human cultures on a massive scale.

His phone hasn't stopped ringing since he published one of the strangest research papers to come out of the mill in quite awhile.

The parasite, Toxoplasma gondii, has been transmitted indirectly from cats to roughly half the people on the planet, and it has been shown to affect human personalities in different ways.

Research has shown that women who are infected with the parasite tend to be warm, outgoing and attentive to others, while infected men tend to be less intelligent and probably a bit boring. But both men and women who are infected are more prone to feeling guilty and insecure.

Other researchers have linked the parasite to schizophrenia. In an adult, the symptoms are like a mild form of flu, but it can be much more serious in an infant or fetus. Oxford University researchers believe high levels of the parasite leads to hyperactivity and lower IQs in children.

Lafferty, who is a parasite ecologist with the U.S. Geological Survey at the University of California at Santa Barbara, is an expert on the role parasites play in the ecology of other animals.

Building on research by scientists in the Czech Republic, Lafferty took a long look at areas of the globe where infection levels are quite high, or quite low. In Brazil, for example, two out of three women of child-bearing age are infected, whereas in the United States the number is only one out of eight.

Lafferty argues in a research paper published Aug. 2 in the Proceedings of the Royal Society, Biology, that aggregate personality types, or what cultures tend to be like, fit neatly with the effects that the parasite produces in individuals.

So that led to a basic question:

Can a common cat parasite account for part -- even if only a very small part -- of the cultural differences seen around the world?

From Lafferty's perspective, that's quite likely, although he admits his theory is a bit off the wall.

"It's kind of way out in left field," he says. "I think it's the strangest thing I've ever worked on."

Bizarre, perhaps, but less so considering the wily parasite that lays the foundation for Lafferty's theory.

Toxoplasma, he notes, is "frighteningly amazing."

It can change the personality of a rat so much that the rat surrenders itself to a cat, just as the parasite wanted.

The parasite's eggs are shed in a cat's feces. A rat comes along, eats the feces, and becomes infected. The behavior of the rat undergoes a dramatic change, making the rat more adventuresome and more likely to hang out around cats.

The cat eats the rat, and the parasite completes its life cycle.

That manipulation of the local ecology is not unusual for a parasite, Lafferty says.

"This is something that many parasites do," he says. "Many manipulate hosts' behavior."

So it wasn't much of a jump to the next question.

"We have a parasite in our brain that is trying to get transmitted to a cat," he says. "This changes an individual's personality."

So if enough personalities are changed in a given society, will the culture of that society also be changed?

He's not suggesting that it's a big player in cultural evolution. Lots of other things are more powerful, ranging from geography to weather to the availability of natural resources.

But if enough of us are infected and undergo personality changes, will that also alter our combined personalities or our culture?

Lafferty admits anthropologists are not likely to embrace his theory. A single powerful leader can have a dramatic impact on a culture. We can all think of examples. But can the collective personality have a similar effect?

"Anthropologists are not in agreement that you can drive a culture from the bottom up," Lafferty says.

But he sees that happening throughout the parasitic world, involving many types of animals, so why is it inconceivable that it could also be happening among humans?

It will be a long time before we have the answer to that, if we ever do, but in the meantime here's a bit of good news.

Cat lovers need not get rid of their cats. The chances are not great that a modern cat, kept on a diet of safe cat food and not left to feed off rats, will transmit the parasite to humans. It's possible, but not likely, Lafferty says.

He ought to know. As a kid he had cats, so after he got into this line of research he assumed he had been infected with the parasite.

"So after I submitted the paper I put down my 30 bucks and got a blood test," he says. "It came out negative. I was so surprised."

And that leads him to this final comment:

"This isn't about trying to freak cat owners out," he says. "Simply having a cat as a pet doesn't mean you're going to get infected, for sure."

Of course, maybe some other parasite is making him say that.
http://a.abcnews.com/Technology/DyeHard/Story?id=2288095&page=1

[yunowu]

2009-05-04
A high-seas mission departs from San Francisco next month to map and explore a sinister and shifting 21st-century continent: one twice the size of Texas and created from six million tonnes of discarded plastic.

Scientists and conservationists on the expedition will begin attempts to retrieve and recycle a monument to throwaway living in the middle of the North Pacific.

The toxic soup of refuse was discovered in 1997 when Charles Moore, an oceanographer, decided to travel through the centre of the North Pacific gyre (a vortex or circular ocean current). Navigators usually avoid oceanic gyres because persistent high-pressure systems — also known as the doldrums — lack the winds and currents to benefit sailors.

Mr Moore found bottle caps, plastic bags and polystyrene floating with tiny plastic chips. Worn down by sunlight and waves, discarded plastic disintegrates into smaller pieces. Suspended under the surface, these tiny fragments are invisible to ships and satellites trying to map the plastic continent, but in subsequent trawls Mr Moore discovered that the chips outnumbered plankton by six to one.

The damage caused by these tiny fragments is more insidious than strangulation, entrapment and choking by larger plastic refuse. The fragments act as sponges for heavy metals and pollutants until mistaken for food by small fish. The toxins then become more concentrated as they move up the food chain through larger fish, birds and marine mammals.

“You can buy certified organic farm produce, but no fishmonger on earth can sell you a certified organic wild-caught fish. This is our legacy,” said Mr Moore.

Because of their tiny size and the scale of the problem, he believes that nothing can be solved at sea. “Trying to clean up the Pacific gyre would bankrupt any country and kill wildlife in the nets as it went.”

In June the 151ft brigantine Kaisei (Japanese for Planet Ocean) will unfurl its sails in San Francisco to try to prove Mr Moore wrong. Project Kaisei’s flagship will be joined by a decommissioned fishing trawler armed with specialised nets.

“The trick is collecting the plastic while minimising the catch of sea life. We can’t catch the tiny pieces. But the net benefit of getting the rest out is very likely to be better than leaving it in,” says Doug Woodring, the leader of the project.

With a crew of 30, the expedition, supported by the Scripps Institution of Oceanography and Brita, the water company, will use unmanned aircraft and robotic surface explorers to map the extent and depth of the plastic continent while collecting 40 tonnes of the refuse for trial recycling.

“We have a few technologies that can turn thin plastics into diesel fuel. Other technologies are much more hardcore, to deal with the hard plastics,” says Mr Woodring, who hopes to run his vessels on the recycled fuel.

Plastics bags, food wrappers and containers are the second and third most common items in marine debris around the world, according to the Ocean Conservancy, which is based in Washington. The proportion of tiny fragments, known as mermaid’s tears, are less easily quantified.

The UN’s environmental programme estimates that 18,000 pieces of plastic have ended up in every square kilometre of the sea, totalling more than 100 million tonnes. The North Pacific gyre — officially called the northern subtropical convergence zone — is thought to contain the biggest concentration. Ideal conditions for shifting slicks of plastic also exist in the South Pacific, the Indian Ocean and the North and South Atlantic, but no research vessel has investigated those areas. If this exploratory mission is successful, a bigger fleet will depart in 2010.

Mr Woodring admits that Project Kaisei has limitations. “We won’t be able to clean up the entire ocean. The solution really lies on land. We have to treat plastics in a totally different way, and stop them ever reaching the ocean.”
http://www.timesonline.co.uk/tol/news/environment/article6206498.ece

[yunowu]

"In the case of deglaciation after the penultimate ice age, before 137,000 years ago, we’re talking about ice sheets – that covered most of the USA and Canada and were up to five kilometers thick – simply vanishing."

Dr Alex Thomas, Oxford University,

A team of Oxford researchers have found that fossilized corals from tropical Tahiti show that ice sheets are much more volatile and dynamic than previously thought.


Analysis of the corals suggests that ice sheets can change rapidly over just hundreds of years – events associated with sea level rises of several meters over the same period. It also shows that a natural warming mechanism known as northern hemisphere summer insolation thought to be responsible for ending ice ages does not fit the timing of the end of the last great ice age, around 137,000 years ago.


‘It’s amazing just how rapidly these ‘melting’ – or ‘deglaciation’ – events occurred and how enormous the volumes of ice involved were,’ said Dr Alex Thomas, from the Department of Earth Sciences at Oxford University. ‘In the case of deglaciation after the penultimate ice age, before 137,000 years ago, we’re talking about ice sheets – that covered most of the USA and Canada and were up to five kilometers thick – simply vanishing.’

Recent observations of changes in ice sheets have not prepared us for just how rapidly the covering of ice across the earth can fluctuate and as yet, we have not identified all the natural phenomena which drive deglaciation.

‘Getting to these ancient fossilized corals without damaging the reef and local ocean life is far from easy,’ said Dr Thomas. ‘A robot submersible was sent to survey the ocean floor and placed a target which was used to guide down a drill from a shallow-draft drilling vessel with great precision and extract our cores. We only left a tiny hole behind that soon disappeared – something that was only possible because of the expertise of the Integrated Ocean Drilling Programme.’

090423205104 The fossilized coral within the cores showing sea level changes was then dated using a uranium dating technique at which Oxford’s Department of Earth Sciences is a world-leader. The timing of these changes showed that northern hemisphere summer insolation could not have caused the deglaciation that brought the penultimate ice age to an end.

Dr Thomas said: ‘People had assumed that because this natural warming mechanism matched the timing of deglaciation ending the last ice age (around 21,000 years ago) that it would be responsible for the one before that. What we have shown is that this was not the case. We are starting to understand that recent observations of changes in ice sheets have not prepared us for just how rapidly the covering of ice across the Earth can fluctuate and that, as yet, we have not identified all the natural phenomena which drive deglaciation.’

Posted by Casey Kazan from materials provided by University of Oxford.
http://www.dailygalaxy.com/my_weblog/2009/05/tahiti-coral-reefs-unlock-clue-to-vanishing-ice-age-glaciers.html

[yunowu]

2009-05-03
As described in an article published this week in an advance, online edition of the journal Proceedings of the National Academy of Sciences (PNAS), the work demonstrates some of the classic principles of evolution. For instance, research shows that when different species directly compete for the same finite resource, only the fittest will survive. The work also demonstrates how, when given a variety of resources, the different species will evolve to become increasingly specialized, each filling different niches within their common ecosystem.

Conducted by Sarah Voytek, Ph.D., a recent graduate of the Scripps Research Kellogg School of Science and Technology, the work is intended to advance understanding of Darwinian evolution. Using molecules rather than living species offers a robust way to do this because it allows the forces of evolution to work over the course of mere days, with a trillion molecules in a test tube replicating every few minutes.

"We can study things very quickly," says Scripps Research Professor Gerald Joyce, M.D., Ph.D., who was Voytek's advisor and her coauthor on the paper. Joyce is the dean of the faculty at Scripps Research, where he is also a professor in the Department of Molecular Biology, the Department of Chemistry, and The Skaggs Institute for Chemical Biology.

On the voyage of the HMS Beagle, Darwin collected and studied different species of finches on several of the Galapagos Islands. The finches differed in their beak structure — some had thick, strong beaks and others had thin, delicate ones. Darwin observed that the different finches were each adapted for the specific types of seeds that served as their primary food source. The big-beaked birds were indigenous to the places where the big seeds grew; in areas where there were also small seeds, there were also small-beaked birds. Darwin reasoned that the finches had a common ancestor but had separated into different species — a classic concept in Darwinian evolution known as "niche partitioning," which holds that when two species are competing for resources within a common environment, they become differentiated so that each species adapts to use different preferred resources.

For several years, Joyce has been experimenting with a particular type of enzymatic RNA molecule that can continuously evolve in the test tube. The basis of this evolution comes from the fact that each time one of the molecules replicates, there is a chance it will mutate — typically about once per round of replication — so the population can acquire new traits over time.

Two years ago, Voytek managed to develop a second, unrelated enzymatic RNA molecule that also can continuously evolve. This allowed her to set the two RNAs in evolutionary motion within the same pot, forcing them to compete for common resources, just like two species of finches on an island in the Galapagos.

In the new study, the key resource or "food" was a supply of molecules necessary for each RNA's replication. The RNAs will only replicate if they have catalyzed attachment of themselves to these food molecules. So long as the RNAs have ample food, they will replicate, and as they replicate, they will mutate. Over time, as these mutations accumulate, new forms emerge — some fitter than others.

When Voytek and Joyce pitted the two RNA molecules in a head-to-head competition for a single food source, they found that the molecules that were better adapted to use a particular food won out. The less fit RNA disappeared over time. Then they placed the two RNA molecules together in a pot with five different food sources, none of which they had encountered previously. At the beginning of the experiment each RNA could utilize all five types of food — but none of these were utilized particularly well. After hundreds of generations of evolution, however, the two molecules each became independently adapted to use a different one of the five food sources. Their preferences were mutually exclusive — each highly preferred its own food source and shunned the other molecule's food source.

In the process, the molecules evolved different evolutionary approaches to achieving their ends. One became super efficient at gobbling up its food, doing so at a rate that was about a hundred times faster than the other. The other was slower at acquiring food, but produced about three times more progeny per generation. These are both examples of classic evolutionary strategies for survival, says Joyce.

More information: "Niche partitioning in the coevolution of 2 distinct RNA enzymes," Proceedings of the National Academy of Sciences
http://www.physorg.com/news160231764.html

[yunowu]

2009-05-03
Fourteen Hydroxycut products, marketed as fat burners, low-cost diet aids, and energy enhancers, are being recalled voluntarily by the manufacturer after the FDA received 23 reports of serious liver injuries ranging from jaundice to death.

The FDA announced the recall today at a news conference.

The recalled products include:

* Hydroxycut Regular Rapid Release Caplets
* Hydroxycut Caffeine-Free Rapid Release Caplets
* Hydroxycut Hardcore Liquid Caplets
* Hydroxycut Max Liquid Caplets
* Hydroxycut Regular Drink Packets
* Hydroxycut Caffeine-Free Drink Packets
* Hydroxycut Hardcore Drink Packets (Ignition Stix)
* Hydroxycut Max Drink Packets
* Hydroxycut Liquid Shots
* Hydroxycut Hardcore RTDs (Ready-to-Drink)
* Hydroxycut Max Aqua Shed
* Hydroxycut 24
* Hydroxycut Carb Control
* Hydroxycut Natural


Hydroxycut and Liver Problems

At the news conference, Linda Katz, MD, interim chief medical officer of the FDA's Center for Food Safety and Applied Nutrition, said the agency urges consumers to discontinue use of the Hydroxycut products. Not affected by the recall are Hydroxycut Cleanse and Hoodia products.

The 23 reports of adverse effects include liver damage, elevated liver enzymes (which indicates potential liver damage) and liver damage requiring a transplant. A 19-year-old man died after using Hydroxycut. "The death occurred in 2007," Katz says, "and was reported to the agency at the end of March 2009."

"Hydroxycut products contain a variety of ingredients and herbal extracts," Katz said. The FDA has not yet determined which ingredients or doses are associated with the liver problems, according to Katz.

Other reported health problems include cardiovascular problems, seizures, and serious muscle damage (rhabdomyolysis) that can cause kidney failure.
Hydroxycut Recall: Industry Response

A message on the toll-free number of Iovate Health Sciences USA Inc. lists the recalled products. Jamie Moss, a spokesperson for the company, says the company is issuing a statement.

The statement also says that the company conducts internal analyses of individual ingredients and medical, scientific and toxicological literature reviews on the safety of product ingredients.

On its web site, the company has posted a statement along with answers to common questions. In part, it says: “While this is a small number of reports relative to the many millions of people who have used Hydroxycut products over the years, out of an abundance of caution and because consumer safety is our top priority, we are voluntarily recalling these Hydroxycut-branded products.”

The reports of liver problems and other ill effects associated with the product use don’t prove cause and effect, says John Hathcock, PhD, vice president of scientific and international affairs for the Council for Responsible Nutrition, a Washington, D.C.-based trade association for the dietary supplement industry.

"Right now it's a simple association," he tells WebMD. Only further investigation will determine if the association is a random occurrence or not, he says.

Tod Cooperman, MD, president of ConsumerLab.com, an independent organization that evaluates dietary supplements, has been testing Hydroxycut products. He hasn't issued a report on them yet.

Cooperman agrees it's difficult to pinpoint which ingredients are to blame. "The products contain many ingredients,'' he says.

The FDA advises consumers who have any of the products involved in the recall to discontinue use immediately and return them to the place of purchase. Though not all the recalled products have been linked with serious liver-related adverse reactions, the company agreed to recall the 14 products, according to the FDA.
http://www.webmd.com/diet/news/20090501/hydroxycut-recall-due-to-liver-injuries

[yunowu]

CALL it CSI: Precambrian. About 700 million years ago, one of the most significant - and most mysterious - events in the history of life on Earth occurred. Suddenly, there was more to life than just single-celled microbes. Within a few tens of millions of years, an extraordinary array of large animals appeared, armed with jaws and claws and eyes and brains.

Yet we still know surprisingly little about the origin of multicellular animals. "The different branches of the animal tree evolved very rapidly in a short period, a long time ago," says Nicole King, an evolutionary biologist at the University of California, Berkeley.

The very first animals left few fossil traces. What they did leave were lots of descendants. It is to these descendants that evolutionary detectives have to turn to reconstruct the events of those early years. By comparing the genes of living organisms and painstakingly working out their family trees, they are slowly building up circumstantial evidence and piecing together a sketch of that first animal, our great-to-the-nth-grandmother. And not just its appearance - the detectives are also coming up with a motive, a reason why animals evolved when they did.

The closest living relatives of multicellular animals, or metazoans, have long been considered to be an obscure group of single-celled creatures called choanoflagellates. These little microbes filter food from water using a tail, or flagellum, set in the middle of a crown-like collar. The feeding cells of sponges bear a similar collar - a hint that the earliest metazoan might have been sponge-like. More recently, DNA sequence comparisons have confirmed this close kinship.

However, sponges seem unlikely ancestors. They are little more than a loose assemblage of cells that lack the true tissues and organs found in higher animals. Plus their structure - a porous mass of interconnected water channels - is nothing like that of any other animal. As a result, most zoologists tend to put sponges on a side branch of the animal tree, an abortive experiment that led nowhere. That's what makes Kevin Peterson's results so thought-provoking.
A bath sponge

Peterson, a molecular palaeobiologist at Dartmouth College in Hanover, New Hampshire, and his colleagues compared the sequences of seven genes from 42 species of animal, and then used sophisticated computer programs to assemble the species into the most likely evolutionary tree. Sure enough, sponges branch out near the base - but Peterson's tree differs from most others in a subtle but hugely significant way. Instead of putting sponges on a single side branch, Peterson's tree has sponges on both sides of the trunk.

In other words, the ancestor of all complex animals not only resembled a sponge, it actually was a sponge. "If you had a time machine and brought back the last common ancestor of all living animals, and you gave it to an invertebrate zoology class, they'd call it a bath sponge," says Peterson.

Peterson's conclusion is highly controversial. Other research teams, using similar analyses but an alternative selection of species and different DNA sequences, have fingered other animal groups as most resembling the ancestor.
The mysterious placozoan

For example, a study based on DNA sequences and morphological characteristics of 24 metazoans suggests that the ancestral metazoan most likely resembled not a sponge but an obscure modern-day animal called a placozoan (PLoS Biology, vol 7, e20).

Placozoans are little more than sheets of cells a few millimetres long, with no gut, nerves or muscles. Despite this, they can swim and crawl. Their simplicity makes them a likely model for the common ancestor - except that there might be more to placozoans than we know. Their sex lives are a mystery, for instance, even though DNA analyses show they must have sex.

Another study, of 150 genes in 77 species, puts yet another animal group, the jellyfish-like ctenophores, at the base of the metazoa (Nature, vol 452, p 745). Others scoff at this possibility, since ctenophores are relatively sophisticated predators, which seem unlikely to have evolved before there were other large organisms to prey on.
Early days

Just last month, a new animal tree based on 128 genes from a wide range of animals put sponges as a separate group, distinct from the lineage leading to higher animals (Current Biology, DOI: 10.1016/j.cub.2009.02.052). If this is right, the ancestral metazoan might not have been spongelike in form. Peterson, however, says his latest analysis - as yet unpublished - shows this tree is incorrect.

Perhaps all one can conclude from these attempts to sort out the base of the animal tree is that it is still early days. "So far, the data sets we have do not show robustness. When you add new species, you find different things," says evolution biologist Antonis Rokas of Vanderbilt University in Nashville, Tennessee. "That makes me think it is more wobbly than these authors would have us believe."

On balance, though, most experts think Peterson is probably on the right track. "I think the weight of evidence favours the notion that sponges evolved first," says King. "These other observations are interesting, and we can't rule out the possibility that they might gain more support, but right now the majority of the field is comfortable with the notion that sponges are the earliest-branching."
Bizarre anatomy

So how does that square with the bizarre anatomy of sponges, which would seem to rule them out as the ancestor of higher animals? It is difficult to envision a stepwise progression from adult sponges to more complex animals - but it probably did not happen that way, says Claus Nielsen, an evolutionary morphologist at the University of Copenhagen in Denmark.

Sponges produce free-swimming larval forms not unlike some conceptions of the ancestral animal. These larvae typically live off stored nutrients and settle on the sea floor after a few days. The larvae of one early sponge, however, might have evolved ways of feeding during the larval stage and could thus have remained free-swimming for far longer than normal. Eventually these "larvae" might have begun breeding too, abandoning the "adult" bottom-dwelling stage altogether.

In this scenario, most of the anatomical problems disappear, Nielsen says. He has set out in detail (see "Six steps from single cells to complex animals") how sponge larvae may have evolved into higher animals (Evolution and Development, vol 10, p 241).
No fossil record

All the intermediate organisms in the progression make sense as living, feeding animals - something that is not necessarily true of other, competing scenarios, Nielsen says. "The problem with older theories that started with a ball of cells is that nobody has speculated on how this organism could feed."

A scenario like Nielsen's would help make sense of the sudden burst of animal forms that appears in the fossil record, says Peterson. A world filled solely with soft-bodied sponges filtering bacteria and organic debris from the seawater would leave few fossils and show little morphological change. "Sponges would be palaeontologically invisible," he says. What's more, with nothing but sponges around, there would have been little selection pressure to drive further evolution. "There are no predators in the world's biota. There are no arms races. Effectively, there's no macroevolution."

Then, about 700 million years ago, the Earth's oceans froze over, or nearly so, at least once. During this "Snowball Earth" phase, there would have been fewer and fewer suitable spots for sponge larvae to settle on, says Peterson. Larvae that could drift with the currents for longer would have had a better chance of finding a suitable spot - and any larvae that could take in food while they drifted would thus have had a huge advantage.
Arms race

Eventually, Peterson speculates, some evolved a rudimentary gut. "Most of the genes are there. The ability to digest is there. You just need to get that opening," he says.

With the help of crude guts, some of these early animals may have started to feed on others. This emergence of multicellular animals that preyed on other multicellular animals - however primitive - would have changed everything. Predators capable of chasing and overpowering their prey would have a huge advantage. Potential prey would have to detect and evade the predators to avoid becoming another meal.

The result is an arms race, says Peterson. "You just get better and better with muscles and nervous systems and sense organs." That would have set the stage for the explosive diversification of animal forms that we see in the fossil record.

"You've got these two remarkable singularities - Snowball Earth and the origin of complex animals - at the same time. Is it just a coincidence? I don't think so," says Peterson. If he's right, and if Nielsen's scenario for animal evolution is accurate, then that shadowy being in the oh-so-distant past, our great-to-the-nth-grandmother, was a hungry sponge larva. Put that on your family tree.
Six steps from single cells to complex animals

Claus Nielsen of the University of Copenhagen, Denmark, has proposed that multicellular animals evolved from single-celled organisms in six major steps. Here is a simplified version of his proposed steps. The details of early animal evolution are still hotly debated, however, and his scenario is just one of many competing ones.
http://www.newscientist.com/article/mg20227061.300-sponge-larvae-your-unlikely-ancestors.html?full=true