Adrian M. Lister

The earliest record of human activity in northern Europe

The colonization of Eurasia by early humans is a key event after their spread out of Africa, but the nature, timing and ecological context of the earliest human occupation of northwest Europe is uncertain and has been the subject of intense debate. The southern Caucasus was occupied about 1.8 million years (Myr) ago, whereas human remains from Atapuerca-TD6, Spain (more than 780 kyr ago) and Ceprano, Italy (about 800 kyr ago) show that early Homo had dispersed to the Mediterranean hinterland before the Brunhes–Matuyama magnetic polarity reversal (780 kyr ago). Until now, the earliest uncontested artefacts from northern Europe were much younger, suggesting that humans were unable to colonize northern latitudes until about 500 kyr ago. Here we report flint artefacts from the Cromer Forest-bed Formation at Pakefield (52° N), Suffolk, UK, from an interglacial sequence yielding a diverse range of plant and animal fossils. Event and lithostratigraphy, palaeomagnetism, amino acid geochronology and biostratigraphy indicate that the artefacts date to the early part of the Brunhes Chron (about 700 kyr ago) and thus represent the earliest unequivocal evidence for human presence north of the Alps.

Pleistocene to Holocene extinction dynamics in giant deer and woolly mammoth.

The extinction of the many well-known large mammals (megafauna) of the Late Pleistocene epoch has usually been attributed to ‘overkill’ by human hunters, climatic/vegetational changes or to a combination of both. An accurate knowledge of the geography and chronology of these extinctions is crucial for testing these hypotheses. Previous assumptions that the megafauna of northern Eurasia had disappeared by the Pleistocene/Holocene transition were first challenged a decade ago by the discovery that the latest woolly mammoths on Wrangel Island, northeastern Siberia, were contemporaneous with ancient Egyptian civilization. Here we show that another spectacular megafaunal species, the giant deer or ‘Irish elk’, survived to around 6,900 radiocarbon yr bp (about 7,700 yr ago) in western Siberia—more than three millennia later than its previously accepted terminal date—and therefore, that the reasons for its ultimate demise are to be sought in Holocene not Pleistocene events. Before their extinction, both giant deer and woolly mammoth underwent dramatic shifts in distribution, driven largely by climatic/vegetational changes. Their differing responses reflect major differences in ecology.

Multiplex amplification of the mammoth mitochondrial genome and the evolution of Elephantidae.

In studying the genomes of extinct species, two principal limitations are typically the small quantities of endogenous ancient DNA and its degraded condition, even though products of up to 1,600 base pairs (bp) have been amplified in rare cases. Using small overlapping polymerase chain reaction products, longer stretches of sequences or even whole mitochondrial genomes can be reconstructed, but this approach is limited by the number of amplifications that can be performed from rare samples. Thus, even from well-studied Pleistocene species such as mammoths, ground sloths and cave bears, no DNA sequences of more than about 1,000 bp have been reconstructed. Here we report the complete mitochondrial genome sequence of the Pleistocene woolly mammoth Mammuthus primigenius. We used about 200 mg of bone and a new approach that allows the simultaneous retrieval of multiple sequences from small amounts of degraded DNA. Our phylogenetic analyses show that the mammoth was more closely related to the Asian than to the African elephant. However, the divergence of mammoth, African and Asian elephants occurred over a short time, corresponding to only about 7% of the total length of the phylogenetic tree for the three evolutionary lineages.

The preservation of glacial-interglacial climatic signatures in the oxygen isotopes of elephant skeletal phosphate

Abstract Phosphate δ18O values (δ18Op) of modern elephant bone and teeth are found to vary linearly according to the δ18O of local meteoric water (δ18Omw), a parameter with close ties to regional and local climatic conditions. Enamel, dentine, cementum and bone separates from individual fossil elephant specimens, of Late Pleistocene age, have δOp values which vary by up to elephant specimens. The larger spread in the δ18Op values of the various skeletal phases for the fossil samples is interpreted as evidence for post-depositional alterantion of primary δ18Op signatures of some, if not all, of these fossil skeletal components. In the fossil samples investigated, enamel and dentine phases have systematically lower δ18O values than associated bone and cementum phases. Differential re-equilibration with soil waters, either by the wholesale replacement of primary apatite or by processes of isotopic exchange, is suggested as a mechanism to account for the observed spread in the fossil phosphate δ18O data.

Early and early Middle Pleistocene correlations in the Southern North Sea basin

Abstract On April 8, 1988 a discussion meeting took place at Norwich with the aim of establishing correlations of the Early and Middle Pleistocene stages across the southern North Sea. On the basis of faunal, floral, and palaeoclimatic data the following correlations were considered highly probable. The Pastonian Stage of East Anglia is correlated with the Late Tiglian (TC5) Stage of the Netherlands, and the Bramertonian with the Middle Tiglian (TC1-4b). The possibility that the British Antian and Bramertonian Stages may represent parts of a single climatic event is mentioned. The Ludhamian is probably of Early Tiglian age and the Pre-Ludhamian may equate in part with the Praetiglian Stage. Possible correlation of the Waltonian with part of the Pliocene Reuverian Stage is also suggested. In the later Middle Pleistocene, the Anglian Stage correlates with the continental Elsterian. The precise correlation of the British type Cromerian Stage with part of the ‘Cromerian Complex’ Stage in the Netherlands remains uncertain.

A long-term perspective on ungulate–vegetation interactions

The fossil record of vegetation and ungulates places present conditions and trends in a temporal perspective. Ungulate–vegetation interactions during the last 500 000 years were primarily driven by the climatic variation of the glacial–interglacial cycle. There were distinctive faunas associated with each temperate period and a loss of species diversity only in the present interglacial. Climate change and human activities have interacted during the most recent glacial cycle, accelerating extinction rates. This unique course of events has the consequence that no stable, ‘base-line’ conditions can be recognised. A review of the full-glacial ‘mammoth-steppe’ debate suggests that ungulate populations were limited by available forage, but a mosaic of habitat supported a diverse fauna in Beringia. In the debate over early–mid Holocene ‘wood pasture’, past ungulate populations are one of a range of disturbance factors, including burning, that influenced regional vegetation composition and structure in northern Europe. These debates concerning the scale and impacts of past ungulate–vegetation interactions will not be fully resolved until more is known about past ungulate population sizes. Modelling past scenarios would enhance the value of retrospective studies and help provide goals for management of near-natural ecosystems.

Genetic Structure and Extinction of the Woolly Mammoth, Mammuthus primigenius

The interval since circa 50 Ka has been a period of significant species extinctions among the large mammal fauna. However, the relative roles of an increasing human presence and a synchronous series of complex environmental changes in these extinctions have yet to be fully resolved. Recent analyses of fossil material from Beringia have clarified our understanding of the spatiotemporal pattern of Late Pleistocene extinctions, identifying periods of population turnover well before the last glacial maximum (LGM: circa 21 Ka) or subsequent human expansion. To examine the role of pre-LGM population changes in shaping the genetic structure of an extinct species, we analyzed the mitochondrial DNA of woolly mammoths in western Beringia and across its range. We identify genetic signatures of a range expansion of mammoths, from eastern to western Beringia, after the last interglacial (circa 125 Ka), and then an extended period during which demographic inference indicates no population-size increase. The most marked change in diversity at this time is the loss of one of two major mitochondrial lineages.

Insular dwarfism in hippos and a model for brain size reduction in Homo floresiensis

Body size reduction in mammals is usually associated with only moderate brain size reduction, because the brain and sensory organs complete their growth before the rest of the body during ontogeny. On this basis, ‘phyletic dwarfs’ are predicted to have a greater relative brain size than ‘phyletic giants’. However, this trend has been questioned in the special case of dwarfism of mammals on islands. Here we show that the endocranial capacities of extinct dwarf species of hippopotamus from Madagascar are up to 30% smaller than those of a mainland African ancestor scaled to equivalent body mass. These results show that brain size reduction is much greater than predicted from an intraspecific ‘late ontogenetic’ model of dwarfism in which brain size scales to body size with an exponent of 0.35. The nature of the proportional change or grade shift observed here indicates that selective pressures on brain size are potentially independent of those on body size. This study demonstrates empirically that it is mechanistically possible for dwarf mammals on islands to evolve significantly smaller brains than would be predicted from a model of dwarfing based on the intraspecific scaling of the mainland ancestor. Our findings challenge current understanding of brain–body allometric relationships in mammals and suggest that the process of dwarfism could in principle explain small brain size, a factor relevant to the interpretation of the small-brained hominin found on the Island of Flores, Indonesia.

The mammalian faunas of Pakefield/Kessingland and Corton, Suffolk, UK: evidence for a new temperate episode in the British early Middle Pleistocene

Abstract It has been recognised for some time that early Middle Pleistocene mammal faunas in Britain can be divided into an earlier group with Mimomys savini (e.g. West Runton Freshwater Bed—WRFB), and a later group with Arvicola terrestris cantiana (Boxgrove, Westbury, Ostend), representing two or more temperate/interglacial stages. On the basis of the available early Middle Pleistocene non-marine molluscan faunas, Meijer and Preece (in: C. Turner (Ed.), The Early Middle Pleistocene in Europe, Balkema: Rotterdam, 1996, pp. 53–82.) and Preece (Quaternary Science Reviews 20 (2001)) recognised three biostratigraphic groups, representing at least three temperate stages. These are largely compatible with the vertebrate faunas, but new evidence presented here strongly indicates that Pakefield/Kessingland represents an additional, hitherto unrecognised temperate stage with Mimomys savini, younger than the WRFB but older than Little Oakley, Boxgrove and Westbury.New exposures and finds from the Cromer Forest-bed Formation at Pakefield, Suffolk have prompted a fresh look at the palaeontology of Pakefield/Kessingland and also Corton, which has a similar lithostratigraphic and biostratigraphic sequence. The large-mammal fauna (at least in part pollen substage II) includes Hippopotamus sp., Palaeoloxodon antiquus, and Megaloceros dawkinsi—none of which has so far been found in the WRFB—strongly suggesting that the Suffolk sites represent a distinct stage. Further, no records of ‘southern’ European plant, invertebrate or vertebrate taxa have been found in the WRFB, whereas the plants Trapa natans and Salvinia natans—indicating summers warmer than now—are known from Pakefield/Kessingland and Corton, providing corroborative evidence for a stage distinct from the Cromerian s.s.

Natural history collections as sources of long-term datasets

In the otherwise excellent special issue of Trends in Ecology and Evolution on long-term ecological research (TREE 25(10), 2010), none of the contributors mentioned the importance of natural history collections (NHCs) as sources of data that can strongly complement past and ongoing survey data. Whereas very few field surveys have operated for more than a few decades, NHCs, conserved in museums and other institutions, comprise samples of the Earths biota typically extending back well into the nineteenth century and, in some cases, before this time. They therefore span the period of accelerated anthropogenic habitat destruction, climate warming and ocean acidification, in many cases reflecting baseline conditions before the major impact of these factors.