This is the blog for GW students taking Human Evolutionary Genetics. This site is for posting interesting tidbits on: the patterns and processes of human genetic variation;human origins and migration; molecular adaptations to environment, lifestyle and disease; ancient and forensic DNA analyses; and genealogical reconstructions.

GWHEG figure

GWHEG figure

Tuesday, February 27, 2018

Ancient DNA researchers surpass 1000 genome mark

In two papers published in nature the 625 ancient human genomes have been reportedly fully sequenced. This moves the total of ancient genomes sequenced above the 1000 mark to more than 1300. Researchers claim that the The large sample sizes magnify the power of studies that delve into:
  • Genetic variation within a specific region and how it changes over time
  • The evolution of genes that affect complex traits
  • The distribution of families within and across grave sites
  • Matrilocality and patrilocality -- areas where women stayed in the same place and men moved, and vice versa

Science daily:

- Louis Gorgone

Through Ancient DNA analysis, research reveal that there could be a link between the spread of the disease and squirrels

Ancient DNA analysis of a skull of a woman from East Anglia, afflicted by pathological lesions, has indicated that rodents may contribute to the spread  of diseases. When the skull was first analyzed some abnormalities were apparent on its face and were linked to a number of diseases including leprosy. Through the analysis of Ancient DNA, researchers were able to confirm that this woman was afflicted by leprosy. Furthermore, they found that the bacterium that caused this disease was also present in other human skeletal remains from Denmark and Sweden, as well as living squirrels from the south of England suggesting that these small animals could have contributed to the  spread of  this serious disease.

For more information visit:


Ancient DNA and the reintroduction of extinct species: the Eurasian beaver in Britain.

The reintroduction of an extinct species requires consideration of the phylogenetic relatedness of the source population to the original population, as seen in the case of the Eurasian beaver, Castor fiber, which was driven to extinction in Britain and then reintroduced in 2009 (Marr et al. 2018). Ancient DNA analysis was used by Marr et al. (2018) to determine the relationship between the extinct Eurasian beaver in Britain and populations across Europe, in order to determine potential source populations for future reintroductions. It was found that the ancient Eurasian beaver samples from Britain grouped more closely with the Western European populations than the Eastern European ones (Marr et al. 2018). However, within the Western European populations they were shown to not be more closely related to any one population over the others (Marr et al. 2018). However, Marr et al. (2018) also note that increasing the diversity of the genetics in the reintroduced modern populations may also be beneficial for adapting to the current environment, and should be considered alongside phylogenetic analysis using ancient DNA.

Click here for the article.


Marr, M.M., Brace, S., Schreve, D.C., and Barnes, I. (2018) Identifying source populations for the reintroduction of the Eurasian beaver, Castor fiber L. 1758, into Britain: evidence from ancient DNA. Scientific Reports. 8: 2708.

Image: Marr, M.M., Brace, S., Schreve, D.C., and Barnes, I. (2018) Figure 2 from Identifying source populations for the reintroduction of the Eurasian beaver, Castor fiber L. 1758, into Britain: evidence from ancient DNA. Scientific Reports. 8: 2708. Accessed 02/27/18.

Victoria Lockwood

New Phylogeny for Elephant Lineage

The phylogeny of straight-tusked elephants--an extinct elephant species that lived 30,000 years ago--has long puzzled researchers. Traditionally, these creatures have been assumed to be more closely related to Asian elephants as both exhibit high foreheads and double-domed skulls. However, genetic analysis of DNA from fossils of straight-tusked elephants reveals that they are more closely related to African elephants. DNA was extracted and analyzed from four straight-tusked elephant fossils ranging in age from 120,000-240,000 years. Due to the preservation of these fossils--in which the individual was covered with sediment quickly after death--researchers were able to extract DNA. This DNA was then compared to the three genomes of elephant species living today: African elephant, African forest elephant, and Asian elephant. This new phylogeny suggests that the African elephant lineage was not confined just to the continent of Africa in the past, as previously thought.

You can find the article from ScienceNews here and the original journal article here

-Leanne Chambers

Parasites and the flightless birds of New Zealand

Prior to human colonization in the 13th century, the island of New Zealand was home to a variety of now extinct birds, including several flightless ones.  A recent aDNA study examined the relationship between these flightless moa, and parasites.  Here, while looking for aDNA of moa in coprolites, researchers also found the aDNA of unique parasite species which depended on flightless birds.  It appears that along with the extinction of megafauna after human colonization, a mass parasite extinction also followed.

Read the commentary published in PNAS here.

Monday, February 26, 2018

An insight into the burial practices of the late pre-Hispanic Los Amarillos community (northwestern Argentina) through the study of ancient DNA

The aims of the study were to characterize the relationships between members of Amarillos community buried within the same funerary structure through ancient DNA analysis, and to discuss the burial practices and social organization of that community. Eighteen individuals recovered from three different burial structures were studied, and enabled to characterize 13 mitochondrial haplotypes, 5 Y-chromosomal haplotypes and 11 complete autosomal STR profiles. The results revealed that the domestic areas were used as family graves, and that the majority of studied individuals shared maternal lineage, suggesting matrilocal practices.



The Mummy

I have always been fascinated with ancient mummies from Egypt ever since I was a child, so I take any opportunity to learn more about the Egyptian culture. An article that was published last year compared the DNA extracted from three ancient Egyptian mummies to the DNA of a modern Egyptian population. The results showed that ancient Egyptians shared more ancestry with Near Easterners than present day Egyptians who share more ancestry and admixture with people from sub Saharan Africa. This shows the effects that globalization has on genetic diversity, especially in a location that is ideal for admixing with people from Africa, Europe, and Asia. Studying both the ancient and present Egyptian genome can help knit together Egypt’s past while also providing insight to Egypt’s long history of cultural and genetic exchange.

For the original article in nature communications go here