This article is part of a fortnightly column exploring contemporary concepts and issues in genetics.
human nose There is an interesting feature that holds importance in various aspects of our lives. Beyond its practical function, facilitating our breathing and sense of smell, the nose has long been associated with perceptions of beauty, deception, and other aspects of historical significance. Different cultures and societies have their own standards of beauty, and the shape, size, and proportion of the nose often contribute to these ideals. We can also see the importance of the nose in art, literature and other relics of ancient civilizations.
The identification of facial ‘landmarks’ and the calculation of distances between them has been one of the key components of facial recognition, which is used to identify and identify faces in biometric-based security services and many other types of security services around the world. is done for Day-to-day applications – including monitoring, importantly.
Computational methods that can automate these measurements to be faster and more efficient have been developed in recent years and are widely used. For example, the ‘DigiYatra’ application developed by the Government of India and launched in December 2022 is widely used in major airports in India to authenticate the check-in of passengers.
What is the gene behind the human nose?
A recent study – published in communication biologyLed by researchers from University College London and Fudan University and with contributions from researchers around the world – 2D images as a basis and distance measures between facial landmarks calculated in an automated way in more than 6,000 Latin American individuals carried out genetic association studies.
In this way, they identified 42 new genetic loci associated with the human nose. (A ‘locus’, plural ‘loci’, is the position of a particular gene on a human chromosome.) Of these, 26 can be replicated in other populations, including Asians, Europeans and Africans. One of these loci included a locus called 1q32.3 (short for chromosome 1, short arm, locus 32.3), which is linked to human nose height.
This genetic locus was previously shown to be contributed by Neanderthals. The present study adds to this evidence, suggesting that specific variants at genetic loci are associated with midface height. This chromosomal locus encodes for a gene called activating transcription factor 3 (ATF3).
The strongest association to the genetic loci actually came from a regulatory region in the ATF3 gene. While researchers have not suggested that the ATF3 gene is directly involved in skull development, this gene is controlled by a gene called FOXL2, which has been implicated in skull and facial development. Additionally, mutations in the FOXL2 gene can result in facial abnormalities.
Why does nose shape matter?
The shape of the nose may have had evolutionary implications for the better survival of humans, possibly helping them to adapt to the climate prevailing during the time of our ancestors. There is also speculation that the change in shape and size of the nose may have affected the landmark’s ability to maintain certain temperatures and humidity.
It is believed that prehistoric humans and Neanderthals interbred, exchanging genetic material and contributing to the genome of present-day humans, thus shaping human destiny to this day. It is also known as introgression of genomic sequences. Researchers estimate that this interbreeding occurred approximately 70,000–100,000 years ago, leaving a lasting genetic legacy in human populations.
Evolutionary geneticist Svante Pääbo made important contributions to the study of the Neanderthal genome and the transfer of genetic information (introgression) between archaic, long-extinct hominids, Neanderthals, Denisovans, and modern-day humans. (The Denisovans are a subspecies of archaic humans that lived until about 30,000 years ago.)
Dr Paabo’s efforts to understand ancient hominid interbreeding have earned him recognition in the scientific community, and won him the prestigious Nobel Prize for Physiology and Medicine in 2022. They have provided important insights into the evolutionary history of our species and our genetic contributions. inherited from our ancient relatives.
Swedish scientist Svante Paabo poses with a replica of a Neanderthal skeleton at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, October 3, 2022. , Photo Credit: Mathias Schrader/AP
Do we have other genes from Neanderthals?
The present study adds to a growing and important body of evidence on diseases and traits in modern humans that have been influenced by genomic loci from Neanderthals and Denisovans.
A mass of emerging evidence suggests that the Neanderthal genome may have contributed to the development of many skin and blood conditions and some cancers (like liver cancer), and even depression, along with responding to pathogens. The way we define risk may also have contributed.
The origin of humans in Africa, their subsequent migration from the continent, and their interbreeding with Neanderthals, Denisovans, and other archaic hominids, all extinct today, together contributed to various human traits, an active area of research. Is.
in fact, a recent study published in Nature analyzed the diversity of human populations in Africa and reported that early humans diverged from multiple, rather than single, ancestral roots in Africa and that the descendants of only a few of those roots could interbreed with Neanderthals and Denisovans. Different global populations contain varying degrees of genetic components from these ancient human species.
How can this knowledge help us?
By understanding the genetic relationships between them and us, scientists can better understand the genetic diversity and adaptability of our species.
The continued exploration of this interbreeding phenomenon and its consequences for human biology and health represents an exciting frontier in genomic research. As more studies contribute to the existing evidence in this field, our understanding of the interactions between ancient and modern human genomes will continue to deepen.
This knowledge may in turn provide new avenues for the study and treatment of various diseases, as well as build a greater appreciation for the complex tapestry of human genetic heritage.
The writer is a scientist at CSIR Institute of Genomics and Integrative Biology (CSIR-IGIB). The views expressed here are personal.