Building a Better Egg Timer?

Lead Research Organisation: University of York
Department Name: Chemistry

Abstract

Fossil and DNA evidence suggests that our species, Homo sapiens, emerged nearly 200,000 years ago in Africa, but until recently it seemed that many of the signs of what we would consider 'modern behaviour' were not evident until after 50,000 years ago. The archaeological evidence for this crucial period is exceedingly sparse and poorly dated. The dramatic climate and environmental changes that occurred during this period were likely to be critical influences, but in the absence of reliable dating methods it is difficult to link the patchy human record with existing continuous global climate records, or regional records where they exist. The picture has begun to change with the development of new dating methods and accumulating evidence for the early occurrence of modern behaviours, such as marine resource exploitation and the appearance of decorated or decorative objects in several sites. The latter include indications that ostrich eggs were used as containers and as decorative beads. However, at present none of these artefacts can be dated directly and precisely. One method that can be used to date shells and eggshells directly is amino acid racemization (AAR) geochronology, which measures the decay of proteins. Because the decay rate is driven by time and temperature, the relative age can be deduced by comparison with other samples. Determination of an absolute date is more challenging. In order to provide a robust and precise age estimate, the mechanisms that drive the decay reaction must be understood. We have been developing a refinement of amino acid geochronology, called 'Intra-crystalline Protein Decomposition' (IcPD), isolating and analysing only the protein from a particular fraction of shells, where the proteins have been trapped within the shell crystals. This effectively forms a protein 'time capsule', within which changing concentrations of the products and reactants of protein decay should enable us to pick apart the reaction pathways. In the past we have been limited by crude measurements of decay, but technological advances, notably in mass spectrometry, now enable us to observe both products and reactants in considerable detail. We plan to explore the reaction pathways in ostrich eggshell fragments, the ultimate 'egg-timer'. Preliminary results reveal the first evidence of a decay pathway in the main protein entrapped in ancient shell, called struthiocalcin. The protein first appears to split into three pieces and each piece is 'nibbled away' from one end. By using a combination of model systems (synthetic peptides, heated shells and shell proteins) and shell fragments recovered from the stratified and well-dated archaeological sequence in Elands Bay Cave, South Africa, we can explore how this initial pattern develops. Once a more complete picture of decay is understood, we will put together a model of the decay path (which identifies the temperature sensitivity of key reactions). We will then apply this model to estimate the age of eggshell fragments found in a rich archaeological sequence at Pinnacle Point, South Africa, to refine the chronological framework of these early modern human sites. But the ostrich eggshells are more than just egg-timers - if we look at the isotopic composition of the eggshells, this also reveals information about climate and environment. Thus we can establish a robust, directly dated record of changes in vegetation and importantly, in aridity, for the region. This data can be linked to longer climate records to build up a more complete picture of the relationships between changing human behaviour and changing environments.

Publications

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Penkman K (2013) Amino acid geochronology: Recent perspectives in Quaternary Geochronology

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Powell, J. (2011) Dating: an uncertain business.

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Penkman, K.E.H. (2011) Application of AAR to Arabian sites.

 
Description Through this award we have discovered that one amino acid racemises in chain, which is important for medical applications, and recovered the oldest verified intact sequences of protein from 3.8 million year old eggshells.
Exploitation Route The protein degradation work is useful for understanding degenerative diseases.
The dating work is useful for providing ages for sites from the last 2.6 million years.
The longevity of the protein sequences discovered allows evolutionary pictures to be developed from fossil samples.
The enhanced understanding of protein-mineral interactions is important for biomineralisation and materials science studies.
Sectors Environment,Healthcare,Culture, Heritage, Museums and Collections,Pharmaceuticals and Medical Biotechnology

 
Description Our work has formed the basis for several public outreach events, from schoolchildren to the general public, through events, articles and podcasts, informing on how analytical chemistry can be used to understand our human and Earth's history.
First Year Of Impact 2010
Sector Education,Culture, Heritage, Museums and Collections
Impact Types Cultural,Societal

 
Description English Heritage Scientific Advisors meeting
Geographic Reach National 
Policy Influence Type Influenced training of practitioners or researchers
Impact The advice given to the English Heritage Science Advisors has influenced their management of Pleistocene site research.
 
Description Teacher training
Geographic Reach National 
Policy Influence Type Influenced training of practitioners or researchers
Impact Has enabled science teachers to incorporate current research into their teaching for 6th formers.
 
Description Outreach grant
Amount £1,550 (GBP)
Organisation Royal Society of Chemistry 
Sector Learned Society
Country United Kingdom
Start 12/2017 
 
Description Wisdom teeth: refining our understanding of mammalian evolution through dating dental enamel
Amount £796,345 (GBP)
Funding ID NE/S010211/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 08/2019 
End 07/2022
 
Title Inter-laboratory proficiency test 
Description We have developed 6 materials for use in inter-laboratory proficiency tests and collaborative trials for the worldwide amino acid community. We have already undertaken a proficiency test with all the active AAR labs, published in 2013. 
Type Of Material Technology assay or reagent 
Year Produced 2010 
Provided To Others? Yes  
Impact Conducted the first AAR laboratory proficiency test, settings the groundwork for a full collaborative trial. 
URL http://dx.doi.org/10.1016/j.quageo.2012.11.001
 
Description Acheulean Hominin Behavior at Elandsfontein, South Africa 
Organisation George Washington University
Country United States 
Sector Academic/University 
PI Contribution Helped devise the dating strategy, write the amino acid dating portion of the grant. Will process samples and feed data into the geochronology of the project.
Collaborator Contribution Devised main project.
Impact No outputs yet.
Start Year 2011
 
Description Paleoscape: NSF, IPG - Developing and Testing an Integrated Paleoscape Model for the early Middle and Late Pleistocene of the South Coast of South Africa ( led by C. Marean (ASU) $1,000,000), participating scientist 
Organisation Arizona State University
Country United States 
Sector Academic/University 
PI Contribution Participating scientist in NSF, IPG - Developing and Testing an Integrated Paleoscape Model for the early Middle and Late Pleistocene of the South Coast of South Africa (PI C. Marean (ASU) $1,000,000),
Collaborator Contribution PI
Impact Contribution of Curtis Marean to Building a better Eggtimer project (samples, collaboration, workshop, articles in prep)
Start Year 2011
 
Description Tracing eggshell and hence human movement through strontium isotopes. 
Organisation University of Colorado Denver
Department Department of Anthropology
Country United States 
Sector Academic/University 
PI Contribution The archaeological samples which we collected C & N isotope and amino acid data on were used for a study looking at the variation in strontium in a palaeontological and an archaeological site, to look at whether it is feasible to use them to track movement & trade.
Collaborator Contribution Strontium isotope analyses
Impact A manuscript has been submitted for publication as a book chapter, and is currently under review.
Start Year 2015
 
Description Article in Chemistry Review: Cracking the eggtimer 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? Yes
Geographic Reach National
Primary Audience Schools
Results and Impact The article gave an overview of how chemistry can be used to understand the past.

At least one student was inspired to apply to our university to do a Chemistry degree based on the article.
Year(s) Of Engagement Activity 2013
URL http://www.york.ac.uk/chemistry/schools/chemrev/index/
 
Description Chem@Work event 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Workshop activity based around our research which was undertaken by ~ 100 KS4 schoolchildren. Sparked questions and discussions.
Year(s) Of Engagement Activity 2018
 
Description Chemistry World article: Dating the Age of Humans 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Interviewed for magazine article about research on amino acid dating and its importance for dating early human sites.
Year(s) Of Engagement Activity 2015
URL http://www.rsc.org/chemistryworld/2015/11/archaeological-dating-age-humans-cave-art
 
Description Chemistry World podcast 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Interviewed for a podcast about the Chemistry World article on dating early human sites.
Year(s) Of Engagement Activity 2015
URL http://www.rsc.org/chemistryworld/2016/02/podcast-december-2015-cataracts-chocolate-kit-origins
 
Description Eggtimer website 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact website made research accessible

People contacted me after having read the website.
Year(s) Of Engagement Activity 2010,2011,2012,2013,2014
URL https://sites.google.com/a/palaeo.eu/eggtimer/
 
Description INQUA AAR spin-out workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact The INQUA Congress in July 2011 provided an excellent opportunity for the small AAR community to meet for the first time in 13 years. In conjunction with Prof. Darrell Kaufman (Northern Arizona University), Dr. Kirsty Penkman organised a dedicated AAR session as part of the Congress, followed by a day-long break-out workshop and dinner for all the active international AAR laboratories (report in Eos: Wehmiller et al., 2011). It gave the community a great forum to discuss some of the major issues facing the field, as well as some of the more nitty-gritty aspects of our work, and presentations and discussions were led by a range of researchers from across the labs. The two inter-laboratory trials and the NSF-funded development of an AAR database (hosted by NOAA to enable long-term data preservation) were discussed in detail, alongside methodological developments and data processing issues.

Kirsty Penkman and Darrell Kaufman edited a special issue of Quaternary Geochronology arising out of the session, and new collaborative grant proposals are also being submitted.
Year(s) Of Engagement Activity 2011
 
Description Interview for "Analytical Scientist" 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Kirsty Penkman was interviewed for the "Analytical Scientist" magazine, which resulted in a multi-page article.
Year(s) Of Engagement Activity 2017
URL https://theanalyticalscientist.com/issues/1117/on-the-dating-scene/
 
Description Invited lecture: Manchester Metropolitan University 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Invited lecture to the Chemistry and related departments at Manchester Metropolitan University, at which our research was showcased.
Year(s) Of Engagement Activity 2017
 
Description Invited lecture: University of Reading 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Invited lecture to the Chemistry and related departments at University of Reading, at which our research was showcased.
Year(s) Of Engagement Activity 2017
 
Description Invited lecture: the Open University 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Invited lecture to the Chemistry and related departments at the Open University, at which our research was showcased.
Year(s) Of Engagement Activity 2017
 
Description Invited talk to celebrate 10 years of Gold Athena Swan at York Chemistry, May 2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Talk given which showcased our research and the power of collaborating across disciplines.
Year(s) Of Engagement Activity 2018
 
Description Invited talk to school students from Archbishops Holgate School at the National Science Learning Centre 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Talk given to showcase our research to school students, parents and the general public, which sparked questions and discussion afterwards.
Year(s) Of Engagement Activity 2019
 
Description Invited talk to the Association Française pour l'Étude du Quaternaire, Paris, Dec 2016 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Invited speaker to a conference at the French Geological Society, run by the Association Française pour l'Étude du Quaternaire. Sparked questions and considerable discussion, and requests for further work.
Year(s) Of Engagement Activity 2016
 
Description Invited talk, Royal Society of Chemistry Yorkshire section, Leeds, March 2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact Invited lecture to the Royal Society of Chemistry Yorkshire secion, at which our research was showcased.
Year(s) Of Engagement Activity 2018
 
Description Leeds Geological Society invited talk 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact The talk led to questions and discussion.

Interest from the members of the society, and an invite to return to give another talk.
Year(s) Of Engagement Activity 2007,2012
 
Description Media interviews for the elife paper, Sep 2016 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact There was considerable media interest in the elife paper arising from the Eggtimer project, with coverage in international news outlets, including an interview with the BBC. The Daily mail, Science Explorer, Science Daily, Forbes International and the BBC covered the story.
Year(s) Of Engagement Activity 2016
URL http://www.bbc.co.uk/news/science-environment-37473388
 
Description Nursery visit to introduce science 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact An outreach activity was designed and delivered for nursery-age children to introduce them to "science" and what a scientist does. This sparked fantastic questions and discussions with both children and staff.
Year(s) Of Engagement Activity 2017
 
Description Our Changing Climate: Understanding Complex Science and Contentious Policy; public lecture series 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Talk sparked questions and discussion afterwards

Not known
Year(s) Of Engagement Activity 2012
 
Description Outreach for Iziko museum, South Africa 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Developed materials for the Iziko museum in Cape Town, South Africa, designed to be used for museum visits by children and adults.

Development of collaboration with museums in South Africa.
Year(s) Of Engagement Activity 2013,2014
 
Description Palaeo Centre launch 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact The talk and posters led to a lot of interest and discussion.

After the talk I was approached by several members of the public eager to learn more about our work.
Year(s) Of Engagement Activity 2011
 
Description Pittcon Analytical Chemistry conference, Chicago, March 2017 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Keynote speech at major international conference. Key contacts made.
Year(s) Of Engagement Activity 2017
 
Description Poster presentation at American Association of Physical Anthropologists Annual Meeting, Atlanta, April 2016. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Poster presentation (Lee-Thorp, J., Penkman, K., Ecker, M. Crisp, M., Demarchi, B. & Marean, C. 2016. Two proxies from one biomineral: AAR chronology and isotopic palaeoaridity indices from ostrich eggshell in archaeological sites. African Environments Symposium, American Association of Physical Anthropologists Annual Meeting, Atlanta, April 2016).
Year(s) Of Engagement Activity 2016
 
Description Poster presentation at Society of Vertebrate Palaeontology conference, Salt Lake City, USA, Oct 2016 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Poster presentation given (Presslee, S., Macphee, R., Farrell, A., Holden, A., Southon, J. & Collins, M. & Penkman, K. 2016. Radiocarbon dating and proteomic analysis of highly purified bone collagen derived from Rancho La Brea mammal fossils. Society of Vertebrate Palaeontology conference, Oct 2016, Salt Lake City, Utah), using expertise and techniques developed from the Eggtimer project.
Year(s) Of Engagement Activity 2016
 
Description Reconstructing prehistoric hunter gatherer mobility symposium, Montreal, Feb 2016 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Oral presentation (Hodgkins J, le Roux P, Copeland SR, Marean CW, Penkman K, Lee-Thorp J. Negrino, F, Benazzi S, Miller C, Orr C, Peresani M, Riel Salvatore J, Strait D, Meyer D. 2016. Using information from archaeological faunal remains, ecological reconstructions, and strontium isotopes to answer questions about hominin mobility). Used data from the Eggtimer project and expanded it to a new research question using strontium isotopes to track movement of eggshells in archaeology.
Year(s) Of Engagement Activity 2016
 
Description Science Uncovered, Natural History Museum 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? Yes
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Hands-on event allowing detailed discussions

Audience very interested in how analytical chemistry can help us understand the past
Year(s) Of Engagement Activity 2011
 
Description Talk at International Symposium of Biomolecular Archaeology, Oxford, Sep 2016 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Oral presentation (Beatrice Demarchi, Shaun Hall, Teresa Roncal-Herrero, Colin Freeman, Jos Woolley, Molly Crisp, Julie Wilson, Anna Fotakis, Roman Fischer, Benedikt Kessler, Rosa Rakownikow Jersie-Christensen, Jesper Olsen, James Haile, Jessica Thomas, Curtis Marean, John Parkington, Samantha Presslee, Julia Lee-Thorp, Peter Ditchfield, Jacqui Hamilton, Martyn W. Ward, Chunting Michelle Wang, Marvin D. Shaw, Terry Harrison, Manuel Domínguez-Rodrigo, Ross D. E.
MacPhee, Amandus Kwekason, Michaela Ecker, Liora Kolska Horwitz, Michael Chazan, Roland Kröger, Jane Thomas-Oates, John H. Harding, Enrico Cappellini, Kirsty Penkman, Matthew Collins2016. Survival of eggshell peptides over millions of years in Africa is due to mineral binding. International Symposium of Biomolecular Archaeology, Oxford, Sep 2016). Gained considerable interest in audience and reported in the media.
Year(s) Of Engagement Activity 2016
 
Description The great egg RACEmisation game 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact An outreach event, involving a lecture and a game, which brought together chemistry and its application to archaeology and geology.

The success of this event has led to it being used several times over the last year.
Year(s) Of Engagement Activity 2013,2014,2015
 
Description York Festival of Ideas "Discovery Zone" 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Presented our work at a public outreach event, with attendance by over 1500 individuals. The focus was on how chemistry can be used to understand the past, and through development of a range of activities around a "bog body", we were able to showcase the advances our research has made in this area. The feedback was excellent, with many reporting increased interest in science because of the event.
Year(s) Of Engagement Activity 2019
URL http://yorkfestivalofideas.com/2018/community/discovery-zone-2/
 
Description York Festival of Ideas "Science out of the lab" event 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Presented our work at a public outreach event, with attendance by over 2500 individuals. The focus was on how chemistry can be used to understand the past, and through development of a range of activities around a "bog body", we were able to showcase the advances our research has made in this area. The feedback was excellent, with many reporting increased interest in science because of the event.
Year(s) Of Engagement Activity 2017
URL http://yorkfestivalofideas.com/2017/community/science-out-lab-fri/
 
Description York Festival of Ideas "Science out of the lab" event 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Presented our work at a public outreach event, with attendance by over 1000 individuals.
Year(s) Of Engagement Activity 2016
URL http://yorkfestivalofideas.com/2016/community-events/science-out-of-the-lab-2/
 
Description YorkTalks 2015 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Public lecture as part of the launch of the University of York's research strategy.
Year(s) Of Engagement Activity 2015
URL https://www.york.ac.uk/news-and-events/events/public-lectures/spring-2015/york-talks-2015/
 
Description Yornight 2015 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Hands-on display enabled public to see and touch materials, and allowed discussions about how science can tell us about the past.
Year(s) Of Engagement Activity 2015
URL http://yornight.com/2015/
 
Description Yornight at York Archaeological Trust 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? Yes
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Hands-on display enabled public to see and touch materials, and allowed discussions.

Arose interest in audience
Year(s) Of Engagement Activity 2014
URL http://yornight.com/