The oldest human footprints in Europe

By now I’m sure that the vast majority of readers of this blog, if not all, have already read the news about the Happisburg footprints, of almost one million years age, which are coincident with the earliest known dates for archaic human presence in Europe based on other archaeology (H. ergaster or antecessor) and extend their range quite further northwards. So I just want to post a reference, as the study is freely available online for all to read.

Nick Ashton et al., Hominin Footprints from Early Pleistocene Deposits at Happisburgh, UK. PLoS ONE 2014. Open accessLINK [doi:10.1371/journal.pone.0088329]


Investigations at Happisburgh, UK, have revealed the oldest known hominin footprint surface outside Africa at between ca. 1 million and 0.78 million years ago. The site has long been recognised for the preservation of sediments containing Early Pleistocene fauna and flora, but since 2005 has also yielded humanly made flint artefacts, extending the record of human occupation of northern Europe by at least 350,000 years. The sediments consist of sands, gravels and laminated silts laid down by a large river within the upper reaches of its estuary. In May 2013 extensive areas of the laminated sediments were exposed on the foreshore. On the surface of one of the laminated silt horizons a series of hollows was revealed in an area of ca. 12 m2. The surface was recorded using multi-image photogrammetry which showed that the hollows are distinctly elongated and the majority fall within the range of juvenile to adult hominin foot sizes. In many cases the arch and front/back of the foot can be identified and in one case the impression of toes can be seen. Using foot length to stature ratios, the hominins are estimated to have been between ca. 0.93 and 1.73 m in height, suggestive of a group of mixed ages. The orientation of the prints indicates movement in a southerly direction on mud-flats along the river edge. Early Pleistocene human fossils are extremely rare in Europe, with no evidence from the UK. The only known species in western Europe of a similar age is Homo antecessor, whose fossil remains have been found at Atapuerca, Spain. The foot sizes and estimated stature of the hominins from Happisburgh fall within the range derived from the fossil evidence of Homo antecessor.

Figure 8. Vertical image of Area A at Happisburgh.
a. Model of footprint surface generated from photogrammetric survey showing the 12 prints used in the metrical analyses of footprint size; b. Plot of length and width measurements of 12 prints showing possible individuals. Means and standard deviations for foot length and age for modern populations are also shown.
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Posted by on February 15, 2014 in European prehistory, Homo ergaster, Middle Paleolithic, UK


Neolithic and Chalcolithic demographics of Western and Northern Europe

Somehow I missed this important study on the Neolithic and Chalcolithic demographics of Europe, as inferred from the archaeological record (h/t Davidski):
Stephen Shennan et al., Regional population collapse followed initial agriculture booms in mid-Holocene Europe. Nature Communications 2013. Open accessLINK [doi:doi:10.1038/ncomms3486]


Following its initial arrival in SE Europe 8,500 years ago agriculture spread throughout the continent, changing food production and consumption patterns and increasing population densities. Here we show that, in contrast to the steady population growth usually assumed, the introduction of agriculture into Europe was followed by a boom-and-bust pattern in the density of regional populations. We demonstrate that summed calibrated radiocarbon date distributions and simulation can be used to test the significance of these demographic booms and busts in the context of uncertainty in the radiocarbon date calibration curve and archaeological sampling. We report these results for Central and Northwest Europe between 8,000 and 4,000 cal. BP and investigate the relationship between these patterns and climate. However, we find no evidence to support a relationship. Our results thus suggest that the demographic patterns may have arisen from endogenous causes, although this remains speculative.

The most interesting aspect is maybe that the (apparent) demographic changes are detailed for many regions of Europe, but first let’s see the general outlook for the whole area surveyed (Western and Northern Europe, Iberia excluded):

Figure 2: SCDPD-inferred population density change 10,000–4,000 cal. BP using all radiocarbon dates in the western Europe database.
Colored arrows and their annotations are mine.

I decided that it was important to mark the main cultural episodes for reference.
1st Neolithic refers to Impressed-Cardium and Linear Band Pottery cultures, which arrived almost simultaneously to Germany and France (of the surveyed areas), although the Rhône-Languedoc Neolithic is a few centuries earlier than the arrow, which has been standardized to 7500 BP.
Atlantic Neolithic refers to the quite belated arrival of Neolithic to Britain, Ireland and Northern Europe (standardized at 6000 BP). This process was quickly followed and tightly associated with the widespread cultural phenomenon of Dolmenic Megalithism. It is most interesting that the main deviation from the pattern of regular growth concentrates in this period and is clearly positive.
Corded Ware culture (Indoeuropean consolidation in Central and Northern Europe) affected only to Germany and Denmark-Scania within the surveyed regions. It was followed by a more widespread subcultural phenomenon known as Bell Beaker, which almost invariably cases manifests within pre-existent locally rooted cultures. Neither seems to be correlated with demographic expansions in the general overview.
Now let’s take a look at the regional graphs:

Figure 3: SCDPD-inferred population density change 8,000–4,000 cal. BP for each sub-region.
Colored arrows, excepted the blue ones (which mark the local first Neolithic), are mine and mark general pan-European initial chronologies (not local!) for Megalithism, Corded Ware and Bell Beaker in those regions where they had some clear influence.

Here we can appreciate that:
Atlantic Neolithic and its associated Megalithic phenomenon are clearly related to notable demographic expansions in Ireland, Scotland, South England, Denmark and Scania. Megalithic influence may also be associated with some more irregular growth in South and Central Germany but rather not in France nor West Germany. A contemporary weak and irregular growth in North Germany (Brandenburg, Mecklemburg and Schlewig-Holstein) may be correlated with Funnelbeaker (with roots in Denmark) and the first Kurgan development of Baalberge and successor cultures (with roots in Eastern Europe), which would eventually evolve into Corded Ware.
Corded Ware only seems related to clear demographic growth in Jutland (and less resolutely in Scania). Bell Beaker is only linked with clear demographic growth in Ireland (and much more weakly in South England and Central Germany), while elsewhere it is rather associated with decline.
For the exact extension of the various regions as defined for this study, see fig. 1 (map).
As provisional conclusion, it seems obvious to my eyes that the most important demographic growth processes were the various Neolithic cultures but that the Atlantic Neolithic (and associated Megalithism) was particularly dynamic. In contrast Indoeuropean-associated cultural phenomena had a much weaker impact, with some localized exceptions, and are generally associated with local demographic decline instead, at least judging from the archaeological record.
See also:

Italian haploid genetics (second round)

More than a year ago I commented (as much as I could) on the study of Italian haploid genetics by Francesca Brisighelli et al. Sadly the study was published with several major errors in the figures, making it impossible to get anything straight. 
I know directly from the lead author that the team has been trying since then to get the paper corrected but this correction was once and again delayed by apparent inefficiency of PLoS ONE’s management, much to their frustration. Finally this week the correction has been published and the figures corrected.
So let’s give this study another chance:
Francesca Brisighelli et al., Uniparental Markers of Contemporary Italian Population Reveals Details on Its Pre-Roman Heritage. PLoS ONE 2012 (formally corrected in February 2014). Open accessLINK [doi:10.1371/journal.pone.0050794]
Notice please that you have to read the formal correction in order to access the new figures, the wrong ones are still in the paper as such. 
The corrected figures are central to the study:

Figure 1 (corrected). Map showing the location of the samples analyzed in the present study and those collected from the literature (see Table 1).
charts on the left display the distribution of mtDNA haplogroup
frequencies, and those on the right the Y-chromosome haplogroup

So now we know that the Northern mtDNA pie was duplicated in the original graph and that Central Italians are outstanding in R0(xH,V), which reaches 14% (probably most HV*), while they have some other peculiarities relative to their neighbors from North and South: some less U and no detected V. 
Other variations are more clinal: H decreases from North to South while J and T do the opposite.

Figure 3 (corrected). Phylogeny of Y-chromosome SNPs and haplogroup frequencies in different Italian populations.

In the Y-DNA side, the most obvious transition is between the high frequencies of R1b1a2-M269 (R1b3 in the paper) in the North versus much lower frequencies in the South. But also:
  • J2 is notorious in the Central region (and also the South) but rare in the North.
  • G frequencies in the South are double than those of Center and North.
  • The same happens with lesser intensity regarding E1b1b1-M35 (E3b in the study).
  • In contrast haplogroup I is most common in the North. However the Sardinian and sub-Pyrenean clade I2a1a-M26 (I1b2 in the paper), which is also the one documented in Chalcolithic Languedoc, is rare in all regions.

The study also deals with several isolated populations:

Figure 4. Haplogroup frequencies of Ladins, Grecani
Salentini and Lucera compared to the rest of the Italian populations
analyzed in the present study.

All them show large frequencies of mtDNA H relative to their regions. The Grecani Salentini do have some extra Y-DNA E1b1b1 (E3b) and J2, what may indeed underline their partial Greek origins. The Ladini show unusually high frequencies of R1b*(xR1b1a2) and K*(xR1a,R1b,L,T,N3), while the Lucerans are outstanding in their percentage of G.
I want to end this entry with a much needed scolding to the staff of PLoS ONE for their totally unacceptable original sloppiness and delay in the correction. And my personal thanks and appreciation to Francesca Brisighelli for her indefatigable persistence and enthusiasm for her work, which is no doubt of great interest.

Mitochondrial lineages from Myanmar

Myanmar, also known as Burma, has been one of those blind spots in the mapping of human genetics. Finally now we get to know something about the peoples of this SE Asian multiethnic state, although there are limitations because the sampling was performed among refugees in Thailand.
Monica Summerer et al., Large-scale mitochondrial DNA analysis in Southeast Asia reveals evolutionary effects of cultural isolation in the multi-ethnic population of Myanmar. BMC Evolutionary Biology 2014. Open accessLINK [doi:10.1186/1471-2148-14-17]



Myanmar is the largest country in mainland Southeast Asia with a population of 55 million people subdivided into more than 100 ethnic groups. Ruled by changing kingdoms and dynasties and lying on the trade route between India and China, Myanmar was influenced by numerous cultures. Since its independence from British occupation, tensions between the ruling Bamar and ethnic minorities increased.


Our aim was to search for genetic footprints of Myanmar’s geographic, historic and sociocultural characteristics and to contribute to the picture of human colonization by describing and dating of new mitochondrial DNA (mtDNA) haplogroups. Therefore, we sequenced the mtDNA control region of 327 unrelated donors and the complete mitochondrial genome of 44 selected individuals according to highest quality standards.


Phylogenetic analyses of the entire mtDNA genomes uncovered eight new haplogroups and three unclassified basal M-lineages. The multi-ethnic population and the complex history of Myanmar were reflected in its mtDNA heterogeneity. Population genetic analyses of Burmese control region sequences combined with population data from neighboring countries revealed that the Myanmar haplogroup distribution showed a typical Southeast Asian pattern, but also Northeast Asian and Indian influences. The population structure of the extraordinarily diverse Bamar differed from that of the Karen people who displayed signs of genetic isolation. Migration analyses indicated a considerable genetic exchange with an overall positive migration balance from Myanmar to neighboring countries. Age estimates of the newly described haplogroups point to the existence of evolutionary windows where climatic and cultural changes gave rise to mitochondrial haplogroup diversification in Asia.

The main sampled ethnic group are the Karen, who live at the border with Thailand, but the Bamar or Burmans, the largest ethnic group, were also sampled in big numbers. 
Fig. 2.- Origin of samples and mitochondrial haplogroup distribution of Southeast Asian populations. Although most of the study participants originated from Karen State (red), a broad
sample spectrum from nearly all divisions and states of Myanmar (a) was included in this study. b shows the haplogroup distributions of populations from Myanmar and four other Southeast
Asian regions. In the white insert box the haplogroup heterogeneity of two ethnic
groups of Myanmar is illustrated. The hatched area in the map surrounding the border
between Myanmar and Thailand shows the main population area of the Karen people. The
Bamar represent the largest ethnic group (68%) in Myanmar. The size of the pie diagrams
corresponds to sample size.
The smaller samples are only detailed in the supplementary data for what I have seen, so I will not discuss them right now (maybe in an update?). 
Overall all SE Asians including the Southern Han from Hong-Kong appear similar in broad terms. Excepted Laos, this relative similitude is quite apparent in figure 3:
Fig. 3.- Multi-dimensional scaling plot of pairwise Fst-values and haplogroup distribution
of populations from Myanmar and 12 other Asian regions.
A distinct geographic pattern appeared in the multi-dimensional scaling plot (Stress = 0.086;
R2 = 0.970) of pairwise Fst-values: The Myanmar sample fitted very well within the Southeast
Asian cluster, the Central Asian populations formed a second cluster, the Korean sample
represented East Asia, the Afghanistan population was representative for South Asia
and Russia symbolized Western Eurasia. The main haplogroup distributions are displayed
as pie charts. The size of the pie diagrams corresponds to sample size. The proportion
of N-lineages (without A,B and R9’F) increases from very low percentages in Southeast
and East Asia over 50% in Central Asia to more than 75% in Afghanistan and 100% in
the sample of Russian origin. The proportion of the American founding haplogroups
A,B,C and D displayed an interesting pattern: from inexistent in Russians it increased
to more than 50% in East Asian Korea.
Looking at the particular differences in haplogroup frequencies, I’d say that the Thai are quite unremarkable, while the other populations show some peculiarities:
  • Karen: higher frequencies of R9/F, A, C and G
  • Bamar: much higher M* (and extremely diverse)
  • Laotian: higher frequencies of B and M7
  • Vietnamese: more B and N*
  • South Han (Hong-Kong): more D
It is very notable the high diversity of paragroup M* among the Bamar. The authors notice that not more than three individuals shared each different subhaplogroup, what points to a very high diversity within haplogroup M. I don’t have time right now to ponder the various lineages, some of which are newly described, but I probably will in the future, because, together with the high diversity in NE India, they have the potential of shifting the paradigm of Asian colonization by H. sapiens a bit towards the East.
The various M* and other novel haplogroups described in Myanmar is shown in fig. 4. Haplogroups M90 and M91 are new basal M sublineages, along with three other unnamed private lineages, which also appear as basal. Also M20a, M49a and G2b1a are new sublineages further downstream. Within N/R, another newly described lineage is B6a1.
The Bamar are extremely diverse not just within M*:

… the haplogroup composition of Bamar
was exceptionally diverse with 80 different haplogroups and a maximum of 6 samples
in the same haplogroup (Figure 4).

On the other hand, the Karen show the signs of genetic isolation instead, with large concentrations in the same haplogroups.
Interestingly, the authors think that rather than being a receiver, Myanmar was a major source of population to its neighbors:

Migration analyses of Myanmar and four Southeast Asian regions displayed a vivid exchange
of genetic material between the countries and demonstrated a strong outwards migration
of Myanmar to all analyzed neighboring regions (for details see Additional file 4: Table S4).

This influence is most intense to Laos, Thailand and South China, while things are more balanced regarding Vietnam instead.

Planning area of the brain "specifically human".

That’s what a new paper claims, based in scan comparison with macaques.
Franz-Xaver Neubert, Comparison of Human Ventral Frontal Cortex Areas for Cognitive Control and Language with Areas in Monkey Frontal Cortex. Neuron 2014. Pay per viewLINK [doi:10.1016/j.neuron.2013.11.012]


  • Fundamental similarities in human and monkey cognitive control and language areas
  • Monkey areas resemble human cognitive control and language areas
  • These areas differ in how they connect to areas in the temporal cortex
  • Identification of a unique to humans area in the human lateral frontal pole


Human ventrolateral frontal cortex (vlFC) is identified with cognitive processes such as language and cognitive flexibility. The relationship between it and the vlFC of other primates has therefore been the subject of particular speculation. We used a combination of structural and functional neuroimaging methods to identify key components of human vlFC. We compared how vlFC areas interacted with other brain areas in 25 humans and 25 macaques using the same methods. We identified a core set of 11 vlFC components that interacted in similar ways with similar distributed circuits in both species and, in addition, one distinctively human component in ventrolateral frontal pole. Fundamental differences in interactions with posterior auditory association areas in the two species were also present—these were ubiquitous throughout posterior human vlFC but channeled to different frontal regions in monkeys. Finally, there were some differences in interregional interactions within vlFC in the two species.

The vlFC is marked in red
According to the lead author:

This area has been identified with strategic planning and decision making as well as “multi-tasking”.

So, I would say, this implies that we are human, psychologically speaking, mostly because of our planning capacity and related decision-making discernment? Multi-tasking may also be important because it implies the ability of partly or totally stopping an activity, according to priorities, and yet retake it at a later moment, what seems intimately related to planning and decision-making.

It would be most interesting to find out how it works in other intelligent animals such as many cetaceans, elephants or non-human great apes. Macaques are very intelligent anyhow but, from an evolutionary viewpoint, I wonder if other species are more similar to us in this aspect or even have developed their own alternative psycho-architectures with similar results.

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Posted by on February 6, 2014 in human evolution, mind, psychology


Medieval Germans, Hungarians and the spread of lactose tolerance

A new ancient DNA study found that 800 years ago in Dalheim (Western Germany) lactase persistence was already similar to modern day frequencies (h/t to Chad):
Annina Krüttli et al., Ancient DNA Analysis Reveals High Frequency of European Lactase Persistence Allele (T-13910) in Medieval Central Europe. PLoS ONE 2014. Open accessLINK 
[doi: 10.1371/journal.pone.0086251]


Ruminant milk and dairy products are important food resources in many European, African, and Middle Eastern societies. These regions are also associated with derived genetic variants for lactase persistence. In mammals, lactase, the enzyme that hydrolyzes the milk sugar lactose, is normally down-regulated after weaning, but at least five human populations around the world have independently evolved mutations regulating the expression of the lactase-phlorizin-hydrolase gene. These mutations result in a dominant lactase persistence phenotype and continued lactase tolerance in adulthood. A single nucleotide polymorphism (SNP) at C/T-13910 is responsible for most lactase persistence in European populations, but when and where the T-13910 polymorphism originated and the evolutionary processes by which it rose to high frequency in Europe have been the subject of strong debate. A history of dairying is presumed to be a prerequisite, but archaeological evidence is lacking. In this study, DNA was extracted from the dentine of 36 individuals excavated at a medieval cemetery in Dalheim, Germany. Eighteen individuals were successfully genotyped for the C/T-13910 SNP by molecular cloning and sequencing, of which 13 (72%) exhibited a European lactase persistence genotype: 44% CT, 28% TT. Previous ancient DNA-based studies found that lactase persistence genotypes fall below detection levels in most regions of Neolithic Europe. Our research shows that by AD 1200, lactase persistence frequency had risen to over 70% in this community in western Central Europe. Given that lactase persistence genotype frequency in present-day Germany and Austria is estimated at 71–80%, our results suggest that genetic lactase persistence likely reached modern levels before the historic population declines associated with the Black Death, thus excluding plague-associated evolutionary forces in the rise of lactase persistence in this region. This new evidence sheds light on the dynamic evolutionary history of the European lactase persistence trait and its global cultural implications.

Table 2. Results of genetic sex and LP allele genotyping.

So lactase persistence was already highly prevalent in West-Central Germany 800 years ago, much as it is today.
Very interesting also is their mention of a previous study in Medieval Hungarians (Nagy 2011, PPV):

A study of medieval Hungary found moderate levels of LP in local
commoners (33%) ca. AD 900–1100, but extrapolating from these results is
complicated by the region’s history of conquest by lactase
non-persistent Asian invaders.

While these frequencies are clearly much higher than Neolithic ones (zero), they were still much lower than present day (c. 60%). 
They also mention the oldest know lactase persistence alleles in Europe, which correspond to Chalcolithic findings in Götland and the Basque Country, albeit still at low frequencies and, in the Basque case, showing strong linkage disequilibrium pointing to an initial admixture episode between two different populations: one lactose-tolerant and the other intolerant. See this previous entry for more details.
As I see it, these two data points help us to better understand the still very wide window when lactose tolerance spread among Europeans, which begins in the Chalcolithic and, at least in the case of Germany, seems closed by the Middle Ages. Although in the Hungarian case remained still half-way in that period. 
It is quite possible that instead of a single selective swap affecting this trait, the process took place in several bouts, each one with their own geography and timeline. 
Still, the reasons behind this apparent positive selection for milk-digesting genes, remain ill-explained at academic level. Recently I tried to articulate a consistent theory on it, based on the fact that the Metal Ages, when this sweep happened almost certainly, were characterized by the accumulation of agricultural resources, wealth and power in few hands, producing a class-structured society in which the vast majority were poor and lived precarious lives, in which the general availability of, particularly, goat milk may have been an important nutritional relief (calories and proteins). See: Is the ability to digest milk in Europeans caused by ancient social inequality?

More details on the Neanderthal legacy in modern humans

Is straight hair Neanderthal?

A quick note on two recent studies on the relevance of Neanderthal introgression on modern Humankind, notably the “out of Africa” branch.

Sriran Sankararaman et al., The genomic landscape of Neanderthal ancestry in present-day humans. Nature 2014. Pay per viewLINK [doi:doi:10.1038/nature12961]


Genomic studies have shown that Neanderthals interbred with modern humans, and that non-Africans today are the products of this mixture1, 2. The antiquity of Neanderthal gene flow into modern humans means that genomic regions that derive from Neanderthals in any one human today are usually less than a hundred kilobases in size. However, Neanderthal haplotypes are also distinctive enough that several studies have been able to detect Neanderthal ancestry at specific loci1, 3, 4, 5, 6, 7, 8. We systematically infer Neanderthal haplotypes in the genomes of 1,004 present-day humans9. Regions that harbour a high frequency of Neanderthal alleles are enriched for genes affecting keratin filaments, suggesting that Neanderthal alleles may have helped modern humans to adapt to non-African environments. We identify multiple Neanderthal-derived alleles that confer risk for disease, suggesting that Neanderthal alleles continue to shape human biology. An unexpected finding is that regions with reduced Neanderthal ancestry are enriched in genes, implying selection to remove genetic material derived from Neanderthals. Genes that are more highly expressed in testes than in any other tissue are especially reduced in Neanderthal ancestry, and there is an approximately fivefold reduction of Neanderthal ancestry on the X chromosome, which is known from studies of diverse species to be especially dense in male hybrid sterility genes10, 11, 12. These results suggest that part of the explanation for genomic regions of reduced Neanderthal ancestry is Neanderthal alleles that caused decreased fertility in males when moved to a modern human genetic background.

B. Bernot & J.M. Akey, Resurrecting Surviving Neandertal Lineages from Modern Human Genomes. Science 2014. Pay per viewLINK [doi:10.1126/science.1245938]


Anatomically modern humans overlapped and mated with Neandertals such that non-African humans inherit ~1-3% of their genomes from Neandertal ancestors. We identified Neandertal lineages that persist in the DNA of modern humans, in whole-genome sequences from 379 European and 286 East Asian individuals, recovering over 15 Gb of introgressed sequence that spans ~20% of the Neandertal genome (FDR = 5%). Analyses of surviving archaic lineages suggests that there were fitness costs to hybridization, admixture occurred both before and subsequent to divergence of non-African modern humans, and Neandertals were a source of adaptive variation for loci involved in skin phenotypes. Our results provide a new avenue for paleogenomics studies, allowing substantial amounts of population-level DNA sequence information to be obtained from extinct groups even in the absence of fossilized remains.

I don’t have access to the papers (update: I do have the second one now) but, honestly, I don’t have time either, so, even with full access, I would have to be rather shallow, given the complexity of the matter.
Nevertheless I would highlight the following:
Fitness costs
Areas of dense gene presence tend to be more depleted of Neanderthal inheritance, meaning that, at least in many cases Neanderthal genes were deleterious (harmful) in the context of the H. sapiens genome. It’s probable that they worked better in their “native” context of the Neanderthal genome but we must not understimate the risks of low genetic diversity, a problem that affected Neanderthals as well as H. heidelbergensis (species probably including Denisovans or at least their non-Neanderthal ancestry).
Partial hybrid infertility
The areas of very low Neanderthal genetic influence include those of reproductive relevance, including genes affecting the testes and the chromosome X. This is typical of the hybrid infertility phenomenon, which is part of species divergence, making more difficult or even impossible that hybrids can reproduce. This particular item emphasizes that the differential speciation of Neanderthals and H. sapiens was in a quite advance stage already some 100 Ka ago, what does not seem too consistent with the lowest estimates for the divergence of both human species (H. sapiens have been diverging for some 200 Ka and are still perfectly inter-fertile). 
Adaptive Neanderthal hair introgression
On the other hand the Neanderthal genetic legacy has been best preserved in genes that appear to affect keratin (affecting skin, nails and hair). This bit I consider of particular interest because, based on the modern distribution of hair texture phenotypes, I have often speculated that straight hair may be a Neanderthal heritage and this finding seems supportive of my speculation.
It’s possible that straight hair conferred some sort of advantage in some of the new areas colonized by H. sapiens, maybe providing better insulation against rain or cold (the ancestral Sapiens thinly curly hair phenotype is probably an adaption to tropical climate, allowing for a ventilated insulation of the head).
Some 20% of the Neanderthal genome still lives in us
Collectively, that is. The actual expressed genes are probably a quite less important proportion anyhow and the actual individual Neanderthal legacy (expressing genes and junk together) seldom is greater than 3% in any case.