Gillespie-Lynch et al. / Frontiers in Psychology

A chimpanzee named Panpanzee (left) and a child known as GN (right) give the gesture for "go," which involves reaching and pointing when there is no object indicated. Researchers found that young humans and apes drew upon a similar repertoire of gestures.

When it comes to communication, a human infant starts out with hand gestures, much as baby chimps and bonobos do, and all three of those species shift to using more symbols as they grow up. But the shift to symbols is more pronounced for the human and relies more on vocalization. That pattern may well suggest how human language evolved.

These are the lessons drawn from more than a year's worth of observations of a chimp, a bonobo and a young girl. The results were published Thursday in Frontiers in Psychology, an open-access journal.

"It's a new kind of evidence in favor of the gestural origins of language, and it's also a new kind of evidence in favor of the co-evolution of gesture and speech," said one of the study's authors, Patricia Greenfield, a psychology professor at the University of California at Los Angeles.

The similarities in the gestures used by baby chimps, bonobos and humans suggest that the common ancestor of those three primate species made use of the same repertoire around 6 million years ago, Greenfield told NBC News. "The story that gesture was present in our common ancestors because of the similarities we see — that just hits you," she said.

How the study was done
The research team tracked the gestures used by the girl, known only as GN in the study, at her parents' home from the age of 8.5 months to almost 2 years. The chimp and the bonobo, named Panpanzee and Panbanisha respectively, were looked in on regularly at Atlanta's Language Research Center for almost four years, beginning soon after they were born.

All three species spontaneously started pointing with their fingers or arms, or even their heads, to the things that they wanted to call attention to. If they wanted to go somewhere, they just pointed, to nothing in particular. They reached out for things that they wanted, even if those things weren't within reach. They raised their arms when they wanted to be picked up. In all these cases, the researchers counted the gestures as communication only if they were accompanied by eye contact or other behavioral cues demonstrating that there was truly an intent to communicate.

Gillespie-Lynch et al. / Frontiers in Psychology

As chimps and bonobos grew up, they learned to point to printed symbols called lexigrams, as shown in this video image.

As time went on, GN began vocalizing more and more — first, with noises, and eventually with words. Meanwhile, the chimp and the bonobo learned to communicate by pointing at a list of abstract symbols, known as lexigrams.

"Lexigrams were learned, as human language is, during meaningful social interactions, not from behavioral training," Kristen Gillespie-Lynch, a psychologist at City University of New York who headed the research team, said in a news release.

The shift to symbols
As they aged, all three subjects used relatively fewer gestures and significantly more symbols. "The child transitioned more quickly than did the apes," Greenfield said. "The apes never transitioned to using symbols more than gestures."

The researchers saw that as a lesson in human evolution. "The fact that symbols became far more dominant speaks to what happened after the common ancestor, in the human line," Greenfield said.

She said GN's vocalization provided another lesson: "It really speaks to the idea that gestures and vocal language or speech evolved together."

This study is only the latest in a long series of experiments comparing the communication capabilities of humans and other species — and it's hard to make sweeping generalizations on the basis of data from just three individuals. But at least there's now evidence tracing the roots of language back to gestures that may have existed millions of years ago.

"We can call it an existence proof," Greenfield said.

More about cross-species communication:

• Why humans are smarter than chimps
• Dogs (not chimps) are most like humans
• Ravens throw down 'hand' gestures
• Dolphins call each other by name

In addition to Gillespie-Lynch and Greenfield, the authors of "A Cross-Species Study of Gesture and Its Role in Symbolic Development: Implications for the Gestural Theory of Language Evolution" include Yunping Feng, Sue Savage-Rumbaugh and Heidi Lyn.

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the NBC News Science Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with NBCNews.com's stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

By Jennifer Viegas
Discovery News

Bottlenose dolphins call out the specific names of loved ones when they become separated, a study finds.

Other than humans, the dolphins are the only animals known to do this, according to the study, published in the latest Proceedings of the Royal Society B. The big difference with bottlenose dolphins is that these communications consist of whistles, not words.

Earlier research found that bottlenose dolphins name themselves, with dolphins having a “signature whistle” that encodes other information. It would be somewhat like a human shouting, “Hey everybody! I’m an adult healthy male named George, and I mean you no harm!”

The new finding is that bottlenose dolphins also say the names of certain other dolphins.

“Animals produced copies when they were separated from a close associate and this supports our belief that dolphins copy another animal’s signature whistle when they want to reunite with that specific individual,” lead author Stephanie King of the University of St. Andrews Sea Mammal Research Unit told Discovery News.

King and her colleagues collected acoustic data from wild bottlenose dolphins around Sarasota Bay, Fla., from 1984 to 2009. The researchers also intensely studied four captive adult male dolphins housed at The Seas Aquarium, also in Florida.

The captive males are adults that keepers named Calvin, Khyber, Malabar and Ranier.

Getty Images

Bottlenose dolphins communicate through a series of whistles.

These bottlenose dolphins, however, as well as all of the wild ones, developed their own signature whistles that serve as names in interactions with other dolphins.

“A dolphin emits its signature whistle to broadcast its identity and announce its presence, allowing animals to identify one another over large distances and for animals to recognize one another and to join up with each other,” King explained. “Dolphin whistles can be detected up to 20 km away (12.4 miles) depending on water depth and whistle frequency.”

The researchers said dolphins copy the signature whistles of loved ones, such as a mother or close male buddy, when the two are apart. These “names” were never emitted in aggressive or antagonistic situations and were only directed toward loved ones.

The whistle copies also always had a unique variation to them, so the dolphins weren’t merely mimicking each other. The dolphins instead were adding their own “tone of voice” via unique whistling.

While researchers often hesitate to apply the “l word” -- language -- to non-human communications, bottlenose dolphins and possibly other dolphin species clearly have a very complex and sophisticated communication system.

“Interestingly, captive dolphins can learn new signals and refer to objects and it may be that dolphins can use signature whistle copies to label or refer to an individual, which is a skill inherent in human language,” King said.

Heidi Harley, a professor of psychology at New College of Florida, is a leading expert on cognitive processes in dolphins. She agrees with the new paper’s conclusions.

Harley told Discovery News that it can be challenging to study dolphin signature whistles, since it’s difficult to identify which particular dolphin is emitting the sounds, and whether or not the sounds are just mimicked copies.

“This study provides evidence that copies of signature whistles include elements that differ from the whistles of the original whistler, while still maintaining the changes in frequency over time that allow a listener to identify the original whistler,” Harley said. “In addition, that signature whistle copying occurs between close associates, suggesting it is used affiliatively.”

King and her team are now using sound playback experiments to see how wild, free-ranging dolphins respond to hearing a copy of their own signature whistle.

More from Discovery News:

• Photos: Sharks, marine mammals hang in paradise
• Dolphins create 'life raft' for one of their own
• How dolphins stay awake for two weeks

Copyright 2013 Discovery Communications LLC. Reprinted with permission.

This story was originally published on Wed Feb 20, 2013 12:06 PM EST

Steffen Wischmann / University of Lausanne

Researchers used a simulated version of these two-wheeled robots with flashing lights to show how randomness in the occurrence of genetic traits can drive evolution of language.

Even if everything about different groups of animals is identical down to the level of their genes and physical surroundings, they can develop unique ways to communicate, according to an experiment done with robots that use flashing lights to "talk."

The Swiss researchers used the robots to get handle on why there is such diversity in communication systems within and between species, something that is difficult to do in living animals. 

The answer, they found, "is contingencies in evolutionary history, i.e. stochasticity (randomness) in the occurrence order of new ... traits," Steffen Wischmann, a researcher in the department of ecology and evolution at the University of Lausanne, told me in an email.

He and his colleagues started with 20 populations of identical two-wheeled robots each equipped with a camera, a food detection sensor, a simple information processing program, and a ring that could emit a blue or green light.

These robots, grouped in populations of 20 individuals, were placed in an arena containing a food source. The team ranked each robot according to how long they spent at the food source. 

They then used a "standard roulette-wheel selection algorithm" to select 100 robots' programs, or genes, for reproduction, according the paper published this week in the Proceedings of the National Academy of Sciences.

"Because the 'genes' — which encoded specifications of the robots neural controllers, responsible for processing sensory information and producing motor actions — were initially set to random values, the robots behaved unpredictably at first," the journal explains in a news advisory.

"But after 1,000 generations, all 20 populations emitted light to indicate food location. In approximately half the populations, the robots emitted a signal only in the presence of food, while the other populations also emitted a different color light in areas without food."

It turned out that the one-signal robots were the most efficient communicators — they found the food faster — but they were also the weakest competitors when pitted against other groups of robots who communicated with two flashing lights.

In other words, there's a tradeoff between communication efficiency and competitive robustness, the researchers note. And, randomness in evolutionary history can affect the outcome of competition between populations.

"Since the two-signal populations use both signals they can also utilize the signals of other populations independent of which signal this other population uses to signal the presence of food," Wischmann explained to me.

Further analysis of the data gleaned from the robots shows that the signaling differences occurred early in the robots' evolution. 

This randomness in the occurrence of mutations can drive the evolution of language and "might also be involved in speciation processes," the team concludes.

More on language evolution:

• Robots invent their own spoken language
• Grow a new language in your head
• A baby's babble leads to language
• Mice given 'human' version of speech gene

John Roach is a contributing writer for msnbc.com. To learn more about him, check out his website. For more of our Future of Technology series, watch the featured video below.