Did Entering the Cage Turbo Boost Speech?

On the beach

A million years ago some people held a beach party on the coast of what is now Norfolk in England. They paddled about quite a bit in the sand and when they left their tracks got covered over. Last May after a million-year gap the sea washed away the covering and the footprints were exposed again. The link below tells the story.

Reading the newspaper reports, many flint tools from the same period have been found very close to the site at which the footprints where discovered, as well as remains of animals including rhinoceroses and elephants.

So these early humans seem to have made and used tools and it’s speculated that they existed in a harsh environment and were probably predated on by big cats and other carnivores. We have no way of telling if they could talk and probably we never shall have. But rather unexpectedly there could be a connection between whether they were preyed on and whether they had developed speech.

Recently an intriguing study was reported in the New Scientist.The online article, complete with singing birds, is here.

http://www.newscientist.com/article/mg22129550.500-talk-is-cheep-do-caged-birds-sing-a-key-to-language.html?full=true

The article raises the astonishing possibility that speech may have arisen not over some millions of years, but more or less immediately in evolutionary terms, when we improved our safety.

Birdsong

The source of this idea is birds, specifically the Bengal (or Society) Finch. These engaging little birds, now well adapted to domestication, were bred either from a wild finch, the Munia, or possibly from a hybrid between the Munia and a close relative. Either way, authorities agree breeding started about 250 years ago.

Bengal finches are surprisingly versatile songbirds. But why should that be surprising, you may ask, since birds often sing? Well, because the wild ancestors have a song that is very limited, by comparison, and Bengal finch breeders have never selected the birds for their song but only for their plumage and how well they domesticated. So why have they become such skillful songsters, and so quickly?

One theory in that the ancestral Munia was already capable of producing complex songs – the sound producing apparatus and brain structures had already evolved – but only used it abilities in a restricted way.

As with many birds, Munias learn their songs from parents or other nearby adult birds of the same species. In a world where being eaten by a predator is an ever-present risk, it doesn’t do to be too noisy and attract attention. So wild Munia parents balance the need to attract a mate with the risk of becoming a victim, and Munia chicks only hear and learn a limited song repertoire.

But once the finches are in an aviary and largely free from the danger of becoming prey there is nothing to stop the songs becoming more exciting and alluring. A finch can now diversify freely and pass new song variations on to juvenile finches, not by inheritance, but by learning. So this could explain the rapid expansion in the song range of Bengal finches.

The origin of speeches

Where does this tie in with human speech? Well we may have domesticated ourselves. Once we found ways of making our environment safer it might then have become possible to communicate more freely, and this could have allowed the development of speech over a relatively short span of time.

As an aside, it’s also interesting that just as humans have areas of the brain specialized for speech recognition and for speaking, Wenicke’s and Broca’s areas respectively, the finches have brain areas involved in recognizing and generating song.

http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.0030164

Naturally it’s impossible to test the theory that humans domesticated themselves and then speedily evolved language as a result! But it is an interesting and provocative idea. It’s often been pointed out that modern humans have many physical features that could be regarded as signs of domestication.

So just perhaps there could be a (sand) grain of truth in this interesting idea.

The ancient humans who left their footprints may have been a chattering species, or a popular big cat lunch, but probably not both.

Image credits in order

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About partialinsight

One evening I had a stroke. Half my sight vanished overnight. Adapting made me grasp how amazing the visual system and brain are. It also taught me to understand disability completely differently and I'm grateful for the lesson.
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