In this task, you are given an article. Your task is to summarize the article in a sentence.

Example Input: Before this, humanlike creatures - or hominins - ate a forest-based diet similar to modern gorillas and chimps.
Researchers analysed fossilised tooth enamel of 11 species of hominins and other primates found in East Africa.
The findings appear in four papers published in PNAS journal.
Like chimpanzees today, many of our early human ancestors lived in forests and ate a diet of leaves and fruits from trees, shrubs and herbs.
But scientists have now found that this changed 3.5 million years ago in the species Australopithecus afarensis and Kenyanthropus platyops.
Their diet included grasses, sedges, and possibly animals that ate such plants. They also tended to live in the open savannahs of Africa.
The new studies show that they not only lived there, but began to consume progressively more foods from the savannahs.
Source: BBC Nature
Was Australopithecus intensely political?
BBC Nature: Modern and early humans
Researchers looked at samples from 175 hominins of 11 species, ranging from 1.4 to 4.1 million years old.
Their diet was analysed from the chemical make up of their teeth, identifying the carbon isotopes within them.
The ratios of different types of carbon atoms, or isotopes, in fossils can give clues to what a fossil creature ate because different foods have different carbon isotope signatures.
"What we have is chemical information on what our ancestors ate, which in simpler terms is like a piece of food item stuck between their teeth and preserved for millions of years," said Dr Zeresenay Alemseged, from the California Academy of Sciences, co-author on two of the papers.
"Because feeding is the most important factor determining an organism's physiology, behaviour and its interaction with the environment, these finds will give us new insight into the evolutionary mechanisms that shaped our evolution."
It is not yet clear whether the change in diet included animals, but "the possible diets of some of our hominin kin" has been considerably narrowed down, Dr Matt Sponheimer, lead author of another of the papers, told BBC News.
"We now have good evidence that some early hominins began using plant foods that are not used in abundance by living African apes today, and this probably led to a major change in the way they used the landscape.
"One consequence could be that the dietary expansion led to a habitat expansion, as they could travel to more open habitats more efficiently.
"We know that many early hominins lived in areas that would not have readily supported chimpanzees with their strong preference for forest fruits. It could also be argued that this dietary expansion was a key element in hominin diversification."
The study has also answered, at least in part, what researchers have long been speculating - how so many large species of primate managed to co-exist.
"They were not competing for the same foods," said Prof Thure Cerling from the University of Utah, who led one of the research papers.
"All these species who were once in the human lineage, ventured out into this new world of foods 3.5 million years ago, but we don't yet understand why that is."
As well as looking at non-human primates, the researchers analysed fossils from other animals from the same era and did not find any evidence of a change in diet.
This combined research highlights  a "step towards becoming the modern human", said Dr Jonathan Wynn from the University of South Florida, who led the analysis of Australopithecus afarensis.
"Exploring new environments and testing new foods, ultimately might be correlated with further changes in human history."
These four complementary studies give a persuasive account of shifts in dietary niche in East African hominins, Dr Louise Humphrey from the Natural History Museum in London, told BBC news.
Example Output: A new analysis of early human teeth from extinct fossils has found that they expanded their diets about 3.5 million years ago to include grasses and possibly animals.

Example Input: Kestutis Butkevicius, 44, is accused of killing Martynas Krasauskas, 36, at an address in King Street.
Officers were called out at about 08:00 on Sunday.
Mr Butkevicius made no plea at the town's sheriff court and was remanded in custody.
Example Output: A man has appeared in court charged with murder after the death of a man in Peterhead.

Example Input: Veterans have complained that the Military Covenant is not fully implemented in Northern Ireland.
The covenant is a promise to look after members of the armed forces and their families.
The DUP and Conservatives are in talks over a deal at Westminster.
Theresa May is seeking the support of the DUP's 10 MPs after losing her majority in the general election.
Some unionists, including the DUP, have long called for a change in the law in Northern Ireland so that the Military Covenant is implemented in line with the rest of the UK.
On Thursday, DUP MP Ian Paisley tweeted a screenshot of the DUP's pledge to support a change in the law along with the word: "Progress!!"
The covenant means that former members of the armed forces in Great Britain are entitled to some priority medical treatment, and assistance with housing and school places for children.
The same arrangements do not apply to military veterans in Northern Ireland. A lack of specialist mental health treatment for those suffering from post-traumatic stress disorder (PTSD) has been highlighted as the most significant issue.
Sinn FÃ©in has made it clear it would not support any policy that gave priority treatment to military veterans.
Implementation of the covenant is a devolved matter that would require agreement between the first and deputy first ministers at Stormont.
However, DUP sources have said the Westminster government has now agreed to ensure that all the provisions of the covenant are implemented in Northern Ireland in the same way as other parts of the UK.
They point to a section of the Queen's Speech to Parliament on Wednesday and claimed that the party pushed for it to reference the covenant being implemented in the whole of the UK.
The Queen said: "My ministers will continue to invest in our gallant armed forces, meeting the NATO commitment to spend at least two per cent of national income on defence, and delivering on the Armed Forces Covenant across the United Kingdom."
The DUP said the party insisted that the government included the phrase "across the United Kingdom".
A source claimed that effectively means decisions about the implementation of the agreement have been taken out of the hands of the Stormont Assembly.
The covenant, published in 2011, aims "to redress the disadvantages that the armed forces community may face in comparison to other citizens, and to recognise sacrifices made".
It "recognises that the whole nation has a moral obligation to members of the armed forces and their families".
The covenant's two principles are that:
It is unclear at this stage how Westminster could overrule the Northern Ireland Assembly on an issue that was previously devolved.
Example Output:
The DUP has claimed the government has agreed to improve the treatment of military veterans in Northern Ireland as part of any agreement for the party's support.

