Stubtailed macaques

Of course monkeys don’t speak to each other in elaborate paragraphs, but they do communicate by vocalizing. Researchers turn to monkeys in an effort to understand some of the most basic foundations of human communication. The idea is that other primates have rudimentary systems that eventually evolved further in human beings to support spoken language.

A new study looked at how macaque monkeys respond to other monkeys’ efforts at communication in the form of drumming or vocalizing. Researchers found that monkeys reacted to both the same way, not just behaviorally but also neurally. Hearing drumming or vocalizations activated overlapping networks in the monkeys’ temporal lobes. To the scientists, this finding suggests a common origin for vocal and nonvocal communication systems. The study lends some support to the idea that language and music evolved side by side in humans.

Does the theory that human speech and language evolved from gestures and rhythmic music make sense to you?

More information:

• Proceedings of the National Academy of Sciences of the United States of America research article: “Monkey drumming reveals common networks for perceiving vocal and nonvocal communication sounds“
• LiveScience article: “Monkey Drumming Suggests the Origin of Music“

Are chimpanzees altruistic?

Part of possessing the Human Spark might be the inclination toward altruism – helping others even when there’s no benefit to yourself, and maybe even a cost. Obviously human beings have a general capacity to help; think of volunteers rushing to the aftermath of a natural disaster or a pedestrian helping an elderly lady across the street. But is this an impulse we share with other animals? A new study suggests that chimpanzees do help out other chimps – but are much more likely to help if the chimp in need basically asks for it.

In the experiment, chimps were separated in side-by-side clear booths. The researchers wanted to see if the animals would transfer a necessary tool from one to the other – they provided a stick to reel in a juice box and a straw to drink from it. Sometimes chimps spontaneously passed the tool to their partners. But if the recipient actively solicited help by reaching into its partner’s booth or clapping its hands, the giver was more likely to help. The social relationship between the two chimps did affect whether or not help was offered.

Are you surprised to learn that chimps communicate in this way? What do you think the difference is between this study’s observations and the voluntary altruism of human beings?

More information:

• PLoS One article: “Chimpanzees Help Each Other upon Request“

• New Scientist video: “Chimps happy to help – you just have to ask“

• Science Daily article: “Chimpanzees Help Each Other On Request But Not Voluntarily“

Photo by Aaron Logan

One of the ways The Human Spark investigates what makes us uniquely human is by looking at our closest living relatives, the other great apes. Scientists are attacking the question of how we became human from a number of new directions – in addition to analyzing the more traditional hard evidence of ancient fossils. This article in New Scientist magazine explains several ways researchers are gathering data from primate groups alive today to gain insights into early hominid evolution. Tune in to The Human Spark’s second episode to learn more. What do you think these kinds of inferences can add to our understanding of where we came from and how we became who we are?

• New Scientist: “Ape behavior reveals secrets of human evolution“

Heat treatment transforms the poor quality silcrete on the left into the ideal tool making material on the right. (Photo by Kyle Brown / South African Coast Paleoclimate, Paleoenvironment, Paleoecology, Paleoanthropology Project © Copyright Arizona Board of Regents)

Pyroengineering. A big word for what early modern humans learned to do at least 72,000 years ago, according to researchers.

A team of archaeologists says that ancient humans harnessed the power of fire to transform stone raw material into an improved form for tool making. It’s next to impossible to fashion sharp stone blades from a stone called silcrete as it naturally occurs. But if silcrete is heat treated, it can then be worked into advanced tools.

This complex technology is another example of that behavioral modernity we are calling the Human Spark – and it’s occurring on the southern tip of Africa tens of thousands of years earlier than the Human Spark is evident in Europe.

When the Human Spark team filmed with Arizona State University’s Curtis Marean, he told Alan Alda about his group’s discovery at Pinnacle Point in South Africa. Watch this video to hear how the scientists figured out the secret of the silcrete.

More information:

• ScienceNews: “Fire Engineers of the Stone Age“
• New Scientist: “Earliest Fired Knives Improved Stone Age Tool kit“

Written music — in its modern form

Talk about “oldies” music! Scientists recently uncovered the oldest musical instruments, in the form of carved bone and ivory flutes. The pieces were found in Germany and are at least 35,000 years old. Whoever the early modern humans were who made these musical instruments, they clearly had what we’re calling the human spark! The ephemeral music that our ancient ancestors made of course never made it into the fossil record. But these objects hint at the sophistication of their cultural lives. The flutes are also important because they suggest a major difference between modern humans and Neanderthals – both of whom lived in Europe during this time period. Theories abound to explain why music first emerged: does it relate to our cognitive skills like language, or was it used to attract mates, or to build group unity and social cohesion? Why do you think people played these flutes so many thousands of years ago?

• “New flutes document the earliest musical tradition in southwestern Germany”
  Read the abstract of the scientific paper in Nature.
• Boston.com: “Archaeologists unearth oldest musical instruments ever found”
  This article includes a link to a sound clip of a tune on a reproduction flute.
• Cosmiclog: “Music for Cavemen“
• Wall Street Journal: “Magic Flute: Primal Find Sings of Music’s Mystery”
  This article focuses on music’s correlation with the human spark.

In the quest to discover the human spark, researchers often rely on volunteers who let them investigate their behavior, inclinations, and abilities. Average, everyday people… just like you!

A couple of labs at Harvard University have created a Web site called Test My Brain, where the public can participate in online experiments.  Find out how good your “gut number sense” is or how skilled you are at recognizing faces — and contribute to the advance of science at the same time!

Visit Test My Brain

Darwinium masillae

Our series attempts to locate when and where we transitioned into truly modern human beings — the elusive spark, if you will, that allowed us, here on our own tiny branch on the tree of life, to behave the way we do with all our various abilities and features. Part of this quest involves closely examining our direct ancient lineage, as well as our near and not-so-near cousins. Of course evolutionary history is filled with groups that split into various descendant lines as well as those that hit dead ends and fizzled out. These ancient family trees are pieced together through the fossil record. Looking at the various branches on these trees is one way scientists try to figure out the relationships between various animal ancestors and us.

Recent publications about a fossil called Ida provide the latest example of a creature that seems to have lived at one of those branching points where one group of animals was evolving into a recognizably different one. People in the media have jumped all over this beautifully preserved 47-million-year-old fossil, with some even calling it a “missing link.” Of course, there’s never a single missing link in the huge web of animal evolution, but it does appear that Ida, or Darwinium masillae, was a mammal who shared characteristics with the prosimians (such as lemurs) and also with anthropoids (such as monkeys and apes). Keep in mind, there’s a long, long time — and lots of evolution! — between when Ida lived and when our own species appeared on earth maybe 200,000 years ago.

What do you think of all the media hoopla about Ida and what she means?

• Research article: “Complete Primate Skeleton from the Middle Eocene of Messel in Germany: Morphology and Paleobiology“
• Associated Press: “Early Skeleton Sheds Light on Primate Evolution“
• CNN: “Scientists Piece Together Human Ancestry“
• The Independent (UK): “The Big Question: Is ‘Ida’ really the missing link between humans and animals?“

Different animals look at the world with different eyes, literally. The colors a species can perceive is dictated by the types and number of visual pigments found in the retina. Humans and most primates are trichromats, meaning we have three pigment varieties that absorb light in our eyes and then transmit that information to the brain. Some birds and reptiles have four pigments, allowing them to perceive ultraviolet wavelengths that we can’t. And other mammals have just two pigments.

This article from Scientific American examines how our color vision system may have evolved. And through their experiments, authors Gerald Jacobs and Jeremy Nathans discovered some intriguing brain adaptability when new sensory inputs are added.

Over the course of our travels, several experts suggested our ability to mentally time travel to past happenings and future possibilities as one candidate for a uniquely human talent. Now a chimp named Santino at a Swedish zoo seems to be forcing a more nuanced picture of what types of anticipation and planning our closest relatives are capable of.

Santino gets riled up when his enclosure is swamped with human onlookers. So he takes matters into his own hands and hurls stones out at the crowds. But what’s intriguing is that he stockpiles rocks in the morning when he is calm and no visitors are peering in at him. He appears to be anticipating their arrival later in the day and his likely-to-result agitated emotional state. So he serenely builds caches of weapons for use later on.

Of course, our human talents didn’t just jump into existence out of thin air. It’s to be expected that foundations for our abilities can be found in other animals. Santino offers an interesting case study… and a reminder that just because we haven’t spotted a particular ability in other species, or figured out an adequate experiment to address the question, doesn’t mean it’s not there in some form.

LINKS

• Summary of Current Biology article by researcher Mathias Osvath
• BBC Article with link to radio interview with Mathias Osvath
• LA Times: “Stone-throwing chimpanzee displays humanlike planning abilities“
• New York Times: “Zoo Chimp Plans for His Visitors, Stockpiling Rocks“