Paleogenetics. Dr Oscar Lao, Carla Casanova Suárez (PhD student)
Partner organisation Institute of Evolutionary Biology (IBE) CSIC, Barcelona
Early anatomically modern humans (AMH) appeared and initially evolved in a particular environment within the African continent. However, humans have managed to spread all over the world after the Out of Africa event in an extremely short period of time from an evolutionary point of view. Conquering such a wide range of different environments has been possible by biological adaptation -incorporating genetic variants from archaic species by archaic introgression and/or new genetic variants conferring a fitness advantage in the new environments- and mostly by the continuous discovery of new technological advances and cultural adaptations. Of these, the discovery of agriculture ~10 thousand years ago in different regions of the world was of particular relevance, both in terms of human demography, behaviour and environmental changes. Nevertheless, cultural adaptation has not stopped, but accelerated during the industrial revolution -less than 200 years ago- and even more with the digital revolution less than 50 years ago. All these cultural changes are meant to help mankind by changing the environment towards facilitating/reducing physical tasks, minimizing the energetic costs to get high caloric food and reducing parasitic and infectious diseases exposure by increasing sanitation and antibiotics, among others. Because of all these cultural changes, current environment where humans live is far from being the one where we biologically evolved.
Until recently, there was no way to track the recent evolutionary history of a pool of alleles associated to a particular trait. However, advances in the field of ancient DNA have provided a large number of publicly available datasets covering a huge range of evolutionary history in Europe after the Out of Africa event. Hence, this opens the possibility to study the recent evolution of complex phenotypes in human populations. Diet is a particularly interesting phenotype for understanding human evolution. Diet is usually geographically restricted and conditioned by the environment. This implies that it should be easier to identify selective pressures among human populations by comparing them. Moreover, humans have suffered recent dramatic diet changes triggered by cultural innovations such as the Neolithic. This means that such shifts should be identifiable when comparing the genetic variation of individuals living at different time periods. This is particularly interesting when comparing ancient genomes from Paleolithic times and early Neolithic times.
Therefore, this project will investigate whether there are genetic variants associated with diet susceptibility that show evidence of positive selection between Middle and Upper Paleolithic populations. In addition, it will also examine whether there is any evidence for certain complex traits in these populations, such as insulin resistance. As a result, further insights of the evolution with food processing adaptations will be provided. To achieve this, machine learning algorithms are going to be developed for leveraging the statistical power by enabling detection of complex/hidden associations in genotyped data from ancient individuals with diet-related phenotypes. Finally, comparisons among different human populations and periods of the resulting genetic variants will be performed.
Stable isotopes. Professor Hervé Bocherens, Dr Dorothée Drucker, Dr Chris Baumann. Partner organisation University of Tübingen
PROJECT START DATE: NOVEMBER 2023
Carbon (C) and nitrogen (N) stable isotope analysis using bulk collagen has been a major influence in the interpretation of later Palaeolithic diet supporting the procurement and consumption of animal protein. This method rarely detects evidence for plant consumption due to the weak nitrogen signal from plants. An alternative approach, single compound amino acid analysis, that measures the δ15N value of the specific amino acids glutamate and phenylalanine in bone collagen, can recover evidence for consumption of plant protein. Samples of Neanderthal, UP and Mesolithic individuals will be analysed, as well as associated animals to offer insights into the extent of plant consumption and the plant-animal dietary balance.
Paleoecology, Gayana Bexultanova (PhD student), Professor Maurizio Mencuccini, with CREAF, Barcelona.
The Mammoth Steppe, the environment that covered the Eurasian landmass for around 100,000 years played host to several later hominin species including Denisovans, Neanderthals and early modern humans. This project will combine evidence from a wide range of sources to explore the ecological dimensions of the selection and use of medicinal and dietary plants by different societal groups. Medicinal plants likely share a set of functional traits that set them apart from generic food plants and non-medicinal plants. Functional ecology provides a set of conceptual and analytical tools with which to understand the selection of these plants based on shared chemical ecology traits.
Archaeobotany. Dr Cynthia Larbey (Postdoctoral research associate)
This project will recover evidence for the presence of plants from sediments and hearths extracted from Palaeolithic sites in Europe, West Asia and South Africa. This includes charred/desiccated parenchyma, twisted fibres, and fungal spores. By comparing evidence for processing and exploitation of plants for food and raw materials, specifically twisted fibres, this project will evaluate the role that plants played in the comparative plasticity of early modern humans and Neanderthals and their adaptations to various ecologies.
Fibre technology is the foundation of all composite technology, a key indicator of cognitive development as it requires the ability to plan and conduct a suite of subtasks. Composite technology involves attaching two (or more) items together to make a third, such as a stone-tipped wooden spear. Early use wear traces suggesting hafting stone tools to hafts, has been identified on artefacts dating to approximately 500 ka. This project will work with the Twisted Fibre PhD student to investigate the emergence and development of twisted fibre technology and its social, functional and technological implications for human evolution.
Ground stone tools. Dr Laura Longo
(Postdoctoral research associate) Partner organisation Ca’ Foscari University, Venice.
Use-wear traces on the working surface of grinding tools can provide direct evidence for plant mechanical processing. This is significant because soft technologies, such as those involving vegetal resources, are often underrepresented in the archaeological record due to their perishability. During the project, we will investigate the complexity behind plant transformations by identifying and characterizing use-wear traces and use-related biogenic residues associated with the ground stones retrieved in lithic assemblages of the Middle Palaeolithic and Upper Palaeolithic, to understand how they were used, what they were used to grind, and whether there are differences in their uses across different locations and time periods. The designed multidimensional approach, combining imaging (by means of microscopes with different resolutions) and plant residue chemoprofiling (different spectroscopic techniques), will provide novel data to better understand the transformative potential of the under investigated macro-lithic tools’ component of the lithic assemblages. Hence, we will scan unmodified pebbles, slabs, and plaquettes to identify their direct involvement in transforming various plant materials, including starch-rich storage organs, fibres, and dyes. Grinding and cooking starchy plants significantly increase the efficiency of carbohydrate intake by converting them into high GI pre-formed glucose, which can be easily digested. Furthermore, pounding can facilitate other economical transformations, such as fibre processing, making ground stone tools highly informative for reconstructing foodscapes and taskscapes during the Palaeolithic.
Dental calculus, Isobel Littlewood (PhD student).
Dental calculus develops around the teeth and below the gum line in the gingival crevice. Once calcified, it can survive for millions of years. It is an outstanding archaeological material as it ceases to develop after death and, as an adhering waste material, is unconditionally connected to each individual where it is found. Dental calculus contains particles and biomolecular material that have passed through the mouth, either through ingestion or breathing. This can provide direct archaeological evidence for food items, paleoenvironmental information and evidence for use of the mouth as a third hand as well as oral and intestinal pathogens.
Twisted fibre technology. Experimental reconstruction and use wear analysis. PhD project to start 1st July
The technology to twist fibres to make string likely took a very long time to develop, and its roots lie deep in the Palaeolithic. The earliest evidence for twisted fibres is in the evidence for its use, including traces linked to hafting stone tools, and early evidence of long distance marine transport. Material remains of early twisted fibre use emerge in the Early Upper Palaeolithic. These include needles, awls, batons percées, thought by some to be linked to fibre technology, and early shell beads. This project will compile all the evidence for early use of twisted fibre technology. It will also carry out a detailed experimental reproduction programme of technological items. Experimental reconstruction and use of material items will ultimately be used on a range of different animal and plant materials. The use wear traces created will be compared to the traces on archaeological items to identify most probable fibres and types of use. Analysis of fibres recovered from archaeological hearths and sediments will also be carried out.