H. sapiens and H. neanderthalensis

Evolution in the Genus Homo
Annual Review of Ecology, Evolution, and Systematics
Vol. 42: 47-69 (Volume publication date December 2011)
First published online as a Review in Advance on August 11, 2011
DOI: 10.1146/annurev-ecolsys-102209-144653

There is a long-standing debate about whether H. sapiens arose in Africa and then migrated across the globe, replacing any and all premodern Homo populations, or whether these various migrations of modern humans engaged in significant levels (i.e., detectable genetically or morphologically) of interbreeding with the preexisting premodern Homo populations (e.g., Relethford 2001, Stringer 2002). The multiregional continuity hypothesis argues that once H. sapiens left Africa, significant gene flow took place between them and the hominins they encountered (Wolpoff et al. 2000) and that, moreover, this gene flow influenced the nature of regional variations in morphology seen among extant populations of H. sapiens. The strong version of the recent out-of-Africa model also posits that H. sapiens arose in Africa, but it suggests that no significant gene flow took place between them and the hominins they encountered beyond Africa. In the past two decades most of the genetic evidence has favored the recent out-of-Africa hypothesis. A seminal study from Allan Wilson's lab (Cann et al. 1987) suggested that the common ancestor of all (maternally inherited) modern mitochondrial DNA (mtDNA) lived in Africa approximately 200 ka, and studies investigating the evolutionary history of the paternally inherited Y chromosome suggested that the last common ancestor of modern humans lived well within the past 100 ka (Karafet et al. 2008, Thomson et al. 2000). Investigations of single nucleotide polymorphisms (SNPs) and autosomal microsatellites indicate that genetic diversity is highest in Africa and steadily decreases as the distance from the continent increases (Prugnolle et al. 2005, Ramachandran et al. 2005), and prior to 2010 research on mtDNA had not revealed any evidence of admixture (Briggs et al. 2009, Jakobsson et al. 2008, Krings et al. 1997, Serre et al. 2004, Tishkoff et al. 2009).

This perspective was challenged in 2010 with the publication of the draft sequence of the nuclear genome reconstructed from DNA recovered from three H. neanderthalensis fossils from Vindija Cave in Croatia (Green et al. 2010). This study also found that all of the H. sapiens DNA samples tested (with the notable exception of those from Africa) contained between 1% and 4% of the distinctive DNA sequence recovered from Neanderthal fossils. By identifying and analyzing SNPs between the two groups of genomes, the researchers discovered that Neanderthal DNA is significantly closer to non-African modern human DNA than it is to African DNA, and statistical analysis of the gene flow led the researchers to argue that the gene flow was from Neanderthals to the ancestors of non-African modern humans. This evidence suggests that once early anatomically modern humans left Africa, some interbreeding did occur with the indigenous groups of Neanderthals they encountered, conceivably in the Middle East before modern humans moved into Eurasia and prior to the divergence of the European, East Asian, and Papuan groups. These new data are consistent with the assimilation hypothesis espoused by Fred Smith (Smith 1985; Smith et al. 1989, 2005; Trinkaus & Smith 1985). As new evidence accumulates, the theory of modern human origins will most likely move away from a simple recent out-of-Africa explanation to a more intricate and sophisticated account in which several different groups of ancestors lived in pockets around the globe.

The last Homo heidelbergensis and their descendants the Neandertals: Orgnac 3, Lazaret and Zafarraya dating

http://dx.doi.org.ezproxy.lib.utexas.edu/10.1016/j.crpv.2011.06.002

This article presents the dating results recently obtained on three archaeological sites in Europe. At Orgnac 3 (Ardèche, France) from where the last Homo heidelbergensis fossils are associated with the first evidence of levallois technique, two speleothem formations from the 5b–6–7^th layers were U-Th dated with MC-ICPMS, giving an age range of 319–255 ka (2σ) (MIS 8–9), while the volcanic ash-bearing second layer was dated by ⁴⁰Ar/³⁹Ar, obtaining a preliminary date of 308.2 ± 6.8 ka (2σ). The combined ESR/U-Th dating of red deer enamel teeth from Lazaret cave (Alpes-Maritimes, France) attributed ages of 120–190 ka to the Acheulean and pre-Mousterian layers (MIS 6), which is in agreement with previous TIMS U-Th dates between 108 and 44 ka on calcite samples from the overlying TRA trench (MIS 5, 4, 3). At Zafarraya (Andalousie, Espagne), a number of ¹⁴C measurements on charcoal samples as well as combined ESR/U-Th dates on Capra and Equus dental enamels assigned the Mousterian artefacts and neandertalian fossils-bearing deposits an age interval between 42 and 34 ka (MIS 3).

Dating Homo heidelbergensis at Mauer, Germany

Mauer – the type site of Homo heidelbergensis: palaeoenvironment and age

http://dx.doi.org.ezproxy.lib.utexas.edu/10.1016/j.quascirev.2010.01.013

The mandible of Homo heidelbergensis was found 1907 in the sand pit Grafenrain at Mauer in coarse fluvial sands 24 m below the surface, deposited in a former course of the Neckar River. These ‘Mauer sands’ are overlain by a series of glacial-climate loess deposits with intercalated interglacial palaeosols, which can be correlated with Quaternary climate history, thus indicating an early Middle Pleistocene age for H. heidelbergensis. The ‘Mauer sands’ are famous for their rather rich mammal fauna, which clearly indicates interglacial climate conditions. The faunal evidence – in particular the micromammals – place the ‘Mauer sands’ into MIS 15 or MIS 13 although most stratigraphic arguments favour correlation to MIS 15 and therefore to an age of ca 600 ka.

Radiometric dating of the type-site for Homo heidelbergensis at Mauer, Germany

doi:  10.1073/pnas.1012722107

Here we show that two independent techniques, the combined electron spin resonance/U-series method used with mammal teeth and infrared radiofluorescence applied to sand grains, date the type-site of Homo heidelbergensis at Mauer to 609 ± 40 ka. This result demonstrates that the mandible is the oldest hominin fossil reported to date from central and northern Europe and raises questions concerning the phyletic relationship of Homo heidelbergensis to more ancient populations documented from southern Europe and in Africa.

Neanderthals versus Modern Humans: Evidence for Resource Competition from Isotopic Modelling

doi:10.4061/2011/689315

Virginie Fabre, Silvana Condemi, Anna Degioanni and Estelle Herrscher

During later MOIS3, in Europe two populations were present, autochthonous Neanderthals and modern humans. Ecological competition between these two populations has often been evoked but never demonstrated. Our aim is to establish whether resource competition occurred. In this paper, in order to examine the possibility of ecological competition between these two populations, 599 isotopic data were subjected to rigorous statistical treatment and analysis through mixing models. The aim of this paper was to compare dietary strategies of Neanderthals and modern humans over time. Our conclusions suggest that Neanderthals and modern humans shared dietary habits in the particular environmental context of MOIS3 characterised in Europe by climatic deterioration. In this environmental context, the resource competition between Neanderthals and modern humans may have accelerated the disappearance of the Neanderthal population.

Décrire un squelette

1. diagnostic du site - est-ce que ça vaut le coût
2. sondage de 7-10%
3. fouille
4. etude - rapport finale d'operation (RFO)
5. publication

dépot = terme neutre pour des restes
sépulture = geste funéraire

adduction = membre contre
abduction = membre éloigné

extension/flexion

mains

• supination = radius et ulna parallèles
• pronation = radius et ulna croisés

connexion

• stricte
• lâche - légère déconnexion
• déplacée - déconnexion totale

espace colmaté = os restent en place, legères déconnexions
espace vide = plus de déconnexions; colmatage differé souvent
espace mixte = who cares

contraintes transversales/longitudinales
=vêtements, ficelle, cercueil trop étroit/court

effet de paroi = how a wall changed the placement of bones

linceuls=enveloppes textiles enroulées cousues ou épinglées = "shroud"
bas moyen âge
= pieds en extension ou "en danseuse"
=contraintes transversales

vêtements= un peu comme linceuls mais l'effet est plus localisé
=conservation du volume costal
=micro espaces vides où colmatés

1. décrire
2. analyser
3. interpréter

"de haut en bas" = commence pas par les pieds

"Effective" population size

Bocquet-Appel-Recent_Advances_in_Palaeodemography-9781402064234

Chapter 1 by J Hawks.

In the absence of selection, allele frequencies vary as a stochastic process. The parameters influencing this process are themselves demographic: population size and mating pattern. Ultimately, the rate of evolution of a population must be constrained by these parameters. This means that the observable genetic characteristics of populations are to some extent natural estimators of demographic characteristics. The relationship between the demographic parameters of a population and its genetic characteristics may in some cases be approximated by a single parameter: the “effective population size.” Effective population size refers the demographic complexity of some real population to the simplicity of some ideal population — in other words, it is a measure of the extent to which a natural population corresponds to some theoretical population model.

...

The model-dependence of effective population size is rarely considered in analyses of molecular data. Ewens (2004) gives a good account of the problem:

Except in simple cases, the concept [of effective population size] is not directly related to the actual size of the population. For example, a population might have an actual size of 200 but, because of a distorted sex ratio, have an effective population size of only 25. This implies that some characteristic of the model describing this population, for example a leading eigenvalue, has the same numerical value as that of a Wright- Fisher model with a population size of 25. It would be more indicative of the concept if the adjective “effective” were replaced by “in some given respect Wright-Fisher model equivalent.” Misinterpretations of effective population size calculations frequently follow from a misunderstanding of this fact (Ewens, 2004, 37–38).

...

The utility of effective population size comes from the fact that it concatenates many separate stochastic phenomena into a single parameter. As an example, a gene frequency is a single value, with a single degree of freedom. It is therefore sufficient to estimate only a single parameter. This approach obviously runs into trouble when more than one stochastic factor varies in the population.

Climate and the demise of the Neandertals

From "Time for the Middle to Upper Paleolithic transition in Europe"

by Wil Roebroeks; Faculty of Archaeology, Leiden University, P.O. Box 9515, 2300RA Leiden, The Netherlands

http://dx.doi.org.ezproxy.lib.utexas.edu/10.1016/j.jhevol.2008.08.008

Ice core studies have taught us that the time span of Middle and Upper Paleolithic was punctuated by rapid climatic transitions on timescales of centuries or even decades (Adams et al., 1999). Vegetation responses to such rapid fluctuations must have varied on small scales among sites and regions, according to the differences in initial environmental conditions, local and regional species pool, and the climate events concerned, and the same applies to faunal elements, including Neandertals and modern humans. Various authors have suggested that such climatic fluctuations were instrumental in the disappearance of the Neandertals, one of the latest climatic hypotheses having been presented by Mellars (2006) who suggests that their final demise may have coincided with the sudden onset of the much colder and drier conditions of the Heinrich Event 4. However, extremes of temperatures reached during this period were not exceptional, and had been experienced in earlier glacial-interglacial cycles survived by Neandertals, where the extremes of OIS 4 and 6 led to abandonment of the northern parts of Europe, as did the most extreme parts of OIS 2, for modern humans (e.g., Roebroeks et al., 1992). Recently Tzedakis et al. (2007) have also made the point that climate change was probably not the key factor here, as before 28 ka ¹⁴C BP (i.e., according to most of the papers in this volume long after their demise) Neandertals would have faced a pattern of climatic fluctuations that they had been surviving for at least 100,000 years already.

The consequences of Middle Paleolithic diets on pregnant Neanderthal women

http://dx.doi.org.ezproxy.lib.utexas.edu/10.1016/j.quaint.2011.07.002

The authors critique various assumptions made by others about Neanderthal lifeways by showing that Neanderthal births would be impossible under these conditions.

3. Lessons learned
There are a large number of potential lessons to be learned here. Principle among them is that researchers should consider the possibility that previous models have, to one degree or another:

1. Under-appreciated the Neanderthals’ abilities to regulate body temperature;
2. Under-appreciated the Neanderthals’ abilities to efficiently hunt terrestrial animals;
3. Under-appreciated the degree of sexual division of labor within Neanderthal groups generally, and for pregnant and lactating women, specifically;
4. Under-appreciated the amount of non-mammal foods eaten by Neanderthals, such as fish, shellfish, insects, birds and eggs;
5. Under-appreciated the amount of plant foods eaten by Neanderthals;
6. Under-appreciated the differences in metabolic processing of essential nutrients such as protein between Neanderthals and modern humans;
7. Under-appreciated the role of micronutrient deficiencies to Neanderthal extinction;
8. Exaggerated the degree of mobility in the average Neanderthal group compared to modern hunting-gathering societies; and
9. Exaggerated the degree of close-encounter, dangerous hunting techniques that Neanderthal women participated in.

Taille minimale de la population néanderthalienne: modélisation de son extinction

Néandertal

• histoire de la population
• hypothèses sur son extinction
• caractéristiques démographiques
• son environnement (climats)

Démographie

   Paramètres démographiques : données connues et effet sur le devenir de la population

• chez les chasseur cueilleurs actuels
• chez les premiers sapiens
• chez Néandertal  

  taille

  génération time

  sex-ratio

  Nombre d’enfants moyen par femme (à la naissance, qui atteignent l’âge adulte)

  Mono/polygamie

  Endo/exo mariages

parametres sont des intervales pris dans la litterature

Extinction

 Causes de l’extinction des espèces animales 

 (sans intervention de l’homme = sans valeur marchande) :

• changement climatiques
• changements ressources
• … épidémies ???
• fractionnement de la population, …

Modélisation exciton

 Bases de matlab

Transitions or turnovers?

http://dx.doi.org.ezproxy.lib.utexas.edu/10.1016/j.quascirev.2008.08.015

John J. Shea (2008)

Abstract

The East Mediterranean Levant is a focal point for debate about evolutionary continuity among Late Pleistocene hominin populations. Changes in the Levantine Middle and Upper Palaeolithic archaeological records are almost invariably described in terms of adaptive shifts and behavioural transitions, rather than as changes in hominin populations. This paper examines evidence for hominin evolutionary continuity in the Levant between 130 and 25 ka. Two inflection points, one within the Middle Palaeolithic ca 75 ka and the other between the Middle and Upper Palaeolithic ca 45 ka, are examined in light of recently-discovered evidence for rapid climate change and environmental deterioration. It is proposed that both periods mark regional extinctions and turnovers of hominin populations. The first of these occurred among early Homo sapiens, the second among Neanderthals. Each event was followed by dispersal of hominin populations into the Levant from adjacent regions. Differences in Middle vs. Upper Palaeolithic Homo sapiens’ long-term success in the Levant may reflect recently-evolved strategies for coping with rapid climate change and with colder arid habitats.

Classic demographic models

The classic population growth model from Malthus (1798):

The carrying capacity model by Verhulst (1838):

r for rate, K for Karrying Kapacity?

Neander Homo transition citation

Processus démographique et culturel, la « transition » désigne globalement la période allant de l'arrivée des Homo sapiens en Europe à la disparition des Néandertaliens. Elle regroupe donc deux volets, d'une part la disparition des Néandertaliens et les processus qui y ont mené; d'autre part l'apparition des Hommes modernes en Europe et avec eux une culture et une industrie qui leur sont propres. Dès lors, deux conceptions s'opposent a transition a-t-elle été un simple remplacement sans contact d'une espace par une autre (Mellars 1992; Stringer 1988, 1989, 2011; Stringer et Gamble 1994; Stringer et Andrews 1988; Stringer et McKie 1998; Stringer, Barton, et Finlayson 2000) ou bien une période d'échanges (Hawks et Wolpoff 2001; Thorne et Wolpoff 1981; Wolpoff 1992, 1994; Wolpoff et Caspari 2011; Wolpoff et al. 2001) comme le supposent plusieurs auteurs sur la base (i) de certains fossiles (Dobos 2010; Frayer 1992; Smith 1991; Smith, Falsetti, et Donnelly 1989; Thorne et Wolpoff 1981; Trinkaus 2011a; Trinkaus et al. 2003; Wolpoff et al. 1994; Zilhão et Trinkaus 2002), (ii) de certaines études génétiques (Abi-Rached et al. 2011; Green, Krause, et al. 2010 ; Plagnol et Wall 2006; Wall et al. 2009), (iii) de certaines interstratifications (Bordes 2003; Gravina, Mellars, et de l'étude 17 Ramsey 2005 ; Mellars, Gravina, et Bronk Ramsey 2007; Zilhão et al. 2007) ou encore (iiii) de certaines industries lithiques (d'Errico, Zilhão, et al Hublin, Spoor, et al. 1996; White 2001)? Cette question semble fondamentale pour comprendre les pressions exercées par l'arrivée des Homo sapiens en Europe mais elle est cependant très soumise aux datations proposées concernant les derniers Néandertaliens comme les premiers Homo sapiens (Jöris et Street 2008; Jöris et al. 2011).

-Virginie Fabre, Thèse p 16-17

keep the model simple

...trop complexifier un modèle revient à l'orienter. En effet, un modèle très complexe a de grandes chances de conclure par ce qu'on a voulu lui faire dire ; on ne sait alors pas si cela est dû à la construction du modèle lui-même ou aux valeurs attribuées aux différents paramètres. Au contraire, si avec un modèle simple on obtient une représentation cohérente avec l'hypothèse de dэpart, on pourra alors attribuer cette conclusion aux valeurs de paramètres qu'on aura choisies.

-Virginie Fabre, Thèse p 14

Inferring ethnic origin by means of an STR profile

By Lowe et al.

http://dx.doi.org/10.1016/S0379-0738(00)00387-X

They seem to be saying that putting people in arbitrary categories and then trying to guess which category they fit in based on their DNA does not work very well.

LOL Middle Eastern. That's what you get for being at the crossroads of humanity.