German proverb: “Blood is thicker than water.” (But water is wider.)
The formation of human beings, other animals, and plants, with their certain characteristics and qualities, has long been attributed to nature and nurture.
Nature rests on genetic material, as Mendel eloquently discerned in his studies.
Nurture, environmental, enveloping the fetus, childhood, adolescence, and adulthood.
Wild-type zebra finch songs [1]
Great debates question the role of inherited traits and social learning. Does cultural/linguistic diversity arise from genetically determined “universal grammar?”
Oscine birds (Latin oscen: a bird whose notes were used in divining) have highly developed syrinxes (voiceboxes) which allow them to sing impressive songs. Finches are well known oscine birds, even such as those studied in the Galapagos Islands by Darwin.
A well-known North American finch is the cardinal, marking his territory in spring with a distinctive song. See him and hear this brilliant red bird at: http://www.allaboutbirds.org/guide/northern_cardinal/id
Testing genetic influence in the appearance of a wild-type finch song
An experiment was carried out to discover if the wild original zebra finch song would disappear in generations of zebra finch chicks raised in colonies socially separated from wild groups of the species.
Isolated finch chicks were allowed no contact with singing or nonsinging adult zebra finch males. The song disappeared in successive generations, but when descendants of the original finch chicks were given voice coaching, the original zebra finch song reappeared.
Tutoring offspring from the isolate founders allowed identification of alterations in the zebra finch song across tutoring generations in two social environments: tutor-pupil pairs in sound-isolated chambers, and an isolated semi-natural colony.
In both settings, juvenile zebra finches imitated tutors, but changed certain song characteristics. The alterations accumulated over learning generations. Over three or four generations the song reverted to the wild type, typical of the species.
This study demonstrates the appearance of the species typical song culture de novo. This parallels language change and evolution.
Analogous to models seen in quantitative genetics, scientists model the zebra finch song culture as a phenotype encoded genetically in part in the finch chick group, influenced by the environment, requiring generations to emerge.
Are we products of nature, or nurture? This study demonstrates the mechanics of epigenetics, phenotypic expression, and natural selection.
Globally, infants seek phonemes fitting their parents’ speech, engendering a shared tongue. Root DNA serves up a speech platform on which applied phenotypic parts from the environment form a language.
Spring is rife with the fluid songs of finches, charms to “soothe a savage breast.” [2]
References:
[1] Nature 459, 564-568 (28 May 2009) | doi:10.1038/nature07994; Received 4 October 2008; Accepted 16 March 2009; Published online 3 May 2009
Olga Feh©r1, Haibin Wang2, Sigal Saar1, Partha P. Mitra2 & Ofer Tchernichovski1
Department of Biology, City College, City University of New York, New York 10031, USA Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
Correspondence to: Olga Feh©r1 Correspondence and requests for materials should be addressed to O.F. (Email: [email protected]).
[2] William Congreve (24 January 1670 – 19 January 1729) was an English playwright and poet.