Animals may not be able to form words, but they can certainly communicate. Birds use songs and calls, and other animals use a combination of sounds and movements to communicate. Primates have an advanced system of communication that includes vocalization, hand gestures and body language. But even primates stop short of what man has been able to achieve -- spoken language. Our ability to form a limitless number of thoughts into spoken word is one of the things that separates us from our less evolved cousins. While we know that language first appeared among Homo sapiens somewhere between 30,000 and 100,000 years ago, the secret to how language evolved is still unknown, and mainstream theories fall into two distinctly different camps.
One widely held theory is that language came about as an evolutionary adaptation, which is when a population undergoes a change in process over time to better survive. That's where the idea of natural selection comes into play, which is the notion that the specific physical traits of a population make that population more likely to survive its environment -- think the turtle and its shell. The idea here is that language was created to help humans survive. Why? One, humans needed to communicate with each other in order to hunt, farm and defend themselves successfully from the surrounding harsh environment. Being able to communicate using language gave the human species a distinct survival advantage. And two, language was needed for social interaction, according to those who subscribe to the adaptation theory.
In their paper "Natural Language and Natural Selection," researchers Steven Pinker and Paul Bloom theorize that a series of calls or gestures evolved over time into combinations, giving us complex communication, or language. As things became more complicated around them, humans needed a more complex system to convey information to one another. Think of it like this: Early man sees a group of deer he wants to hunt. He grunts a sound to his hunting partner that means "deer are nearby." One day, a storm comes in and the hunter notices that thunder scares the deer away. As a result, the hunter goes hungry until the storm passes. Over time, the same hunter also learns to recognize the warning signs for bad weather -- dark skies and increased wind. Early man realizes that when the sky darkens and the wind picks up, he needs to tell his hunting partner to speed up the pursuit of the deer. Therefore, he comes up with a series of grunts that reference both the deer and the bad weather. That series of grunts was the beginning of an evolutionary adaptation that eventually became language. As humans learned more about how to best survive, they developed a need to communicate these survival methods to their population. And that's the adaptation theory in a nutshell.
We'll discuss the second primary theory on the next page.
Evolution, Adaptation and Language
The other competing theory, posed by linguist Noam Chomsky and evolutionary biologist Stephen Jay Gould, is that language evolved as a result of other evolutionary processes, essentially making it a byproduct of evolution and not a specific adaptation. The idea that language was a spandrel, a term coined by Gould, flew in the face of natural selection. In fact, Gould and Chomsky pose the theory that many human behaviors are spandrels. These various spandrels came about because of a process Darwin called "pre-adaptation," which is now known as exaptation. This is the idea that a species uses an adaptation for a purpose other than what it was initially meant for. One example is the theory that bird feathers were an adaptation for keeping the bird warm, and were only later used for flying. Chomsky and Gould hypothesize that language may have evolved simply because the physical structure of the brain evolved, or because cognitive structures that were used for things like tool making or rule learning were also good for complex communication. This falls in line with the theory that as our brains became larger, our cognitive functions increased.
Of course, researchers can't even agree on what constitutes language among early man. Some consider the proto-language of Homo halibis the first real language. Others say it can be chalked up to Homo erectus, while most believe that what we understand as modern language came from Homo sapiens. We do know that Homo habilis is responsible for bringing tools onto the scene, about 2.3 million years ago. This has led some to believe that the cognitive function of Homo halibis was much more advanced than his predecessor, Australopithecus. According to research, the temporal, parietal and occipital lobes of the brain were physically connected for the first time with Homo halibis. That area of the brain is known now as Wernicke's area, and it has a lot to do with language production. This supports Chomsky and Gold's theory that our brains physically adapted to be able to make tools, and language then arose because of this adaptation.
For those of you who think both camps present pretty good arguments, there's good news: They aren't mutually exclusive. While science now shows us that it's likely there already were neural structures in place that allowed language to evolve, meaning it was likely exapted, that doesn't necessarily explain language in full, with all of its complexities. Stringing words together into sentences and the notion of grammar in language may have a lot to do with natural selection. So perhaps language was originally exapted, but was refined through Darwinian selection. Surely a Homo sapien with more advanced communication skills would have some kind of evolutionary advantage over his single-word grunting cousin. But that more refined Homo sapien wouldn't even have the opportunity to speak his first sentence if his brain hadn't evolved to allow him to make a primitive hammer.
- Branan, Nicole. "Did Language Evolve as a Learning Aid?" Scientific American. June 2008. http://www.scientificamerican.com/article.cfm?id=could-language-have-evolved
- Croom, Christopher. "Did Language Evolve Like the Vertebrate Eye, or Was It More Like Bird Feathers?" Csa.com. December 2003.http://www.csa.com/discoveryguides/lang/overview.php
- Deacon, Terrance. "The Symbolic Species The Co-Evolution of Language and the Brain." Washington Post. 2010.http://www.washingtonpost.com/wp-srv/style/longterm/books/chap1/symbolicspecies.htm
- Marcus, Gary F. "Anthropology: On the Origins of Human Language." Scienceweek.com. 2010. http://scienceweek.com/2004/sa041203-3.htm
- Pinker, Stephen and Bloom, Paul. "Natural Language and Natural Selection." Illinois.edu. 2010. http://www.isrl.illinois.edu/~amag/langev/paper/pinker90naturalLanguage