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 two sources: nature and nurture.
Nature has been exposed as deriving from genetic material, as Mendel so eloquently discerned in his studies of peas.
Nurture is environmental, enveloping childhood, the fetus, adolescence, and adulthood, i.e. rickets-bony and cartilaginous deformities arising in a growing child from inadequate vitamin D intake.
Wild-type zebra finch songs
Maturation in human beings, birds, and other creatures arises in the embryo, and under the influence of genetic and environmental factors, creating structures not present in the egg.
Great debates continue to question the role of inherited traits and social learning in society’s order. Does Cultural diversity includes species specific constraints, arising a genetically determined “universal grammar” underlies all human language.
Passerine or perching birds, contain special muscle and connective tissue structures in their legs allowing stable perching, awake or asleep. Oscine birds (Latin oscen: a bird whose notes were used in divining) are passerine, with highly developed syrinxes (voiceboxes).
Finches, e.g. the northern cardinal, marks his territory and nesting activities with short, staccato strings or warning “chirps” to creatures veering to close to the nest. See and hear him Cornell ornithology .
An experiment was carried out to discover if the wild, original zebra finch song would disappear in zebra finch generations raised from early life in colonies socially separated from wild groups of the species.
groupsyoung zebra finches born to future generations of a colony rapidly set apart socially soon after emerging from the egg (finch chicks). During growth and development these finch chicks had no contact with adult males of their species, singing or not.
On following successive generations, the song disappeared, but when descendants of the original FCs were later given voice coaching in the laboratory and in semi-wild type settings, the original song of the zebra finch 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 but products of nature, or nurture? This study demonstrates the mechanics of epigenetics, phenotypic expression, and natural selection. In fact, in 1831, the HMS Beagle made land in the Galapagos Islands, letting 20 year-old Charles Darwin off to make his studies of finches on those isles, and publish 30 years later The Origin of the Species.
Infants around the globe try out myriads of parts of speech which are matched with the sounds made by their parent imagos and others, engendering the tongue they share.
Spring is rife with the fluid songs of the oscines, and the cacaphony of the others. Such music soothes the savage breast.
References:
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]).