51: More than just a number.

by Kaylee Gund

What’s in a number? They’re symbols we use to quantify the world around us, the basis for astrophysics and time measurement, and among the first things we learn in language.

5: right angle meets curve.

1: straight as a ruler.

Using some mental glue, stick these together and the result is 51, a random number, multiple of seventeen and three, a discrete semi-prime, and the whimsical subject of this blog entry. While probably not in the forefront of your conscious mind, the number 51 has more than a few significant meanings for the Houston Museum of Natural Science, enumerated below (pun intended).

  1. Years

Fifty-one years ago, the original Burke Baker Planetarium was built. The very first venue at the current HMNS, the Planetarium featured cutting-edge projector technology and quite literally made the nation see stars.


The Planetarium closed Dec. 21, 2015 for a complete renovation, but will return better and sharper this March with cutting-edge optics, cloud-enabled digital projection technology, and more seating. Stay tuned to this blog and social media for updates on this exciting project!

  1. Telephone codes

Calling Peru? Dial 51.


Luckily, a visit to South America can be arranged without costly international phone calls. Climb Mayan temple ruins, hear ancient fables come to life, and see one-of-a-kind artifacts in the John P. McGovern Hall of the Americas, a world hidden away on the third floor of the Museum.

  1. Electrons

Antimony (Sb): a soft, lustrous metal element, atomic number 51.


Despite being relatively rare on its own, antimony can be found in mineral form with sulfur, a compound called stibnite. A huge sample of stibnite can be found in the Cullen Hall of Gems and Minerals, looking more like a shiny porcupine than anything else, but stibnite was also used by ancient Egyptians. The poisonous qualities of antimony made it useful as a component of ancient eyeliner, as described in the Hall of Ancient Egypt. Painting the eyelids with a mild toxin made bacterial eye infections, a constant threat in the marshes of the Nile, much less likely to occur.

  1. Genetic breakthroughs

In 1952, the double helix structure of DNA was deduced with the help of an x-ray crystallography image called Photo 51.


Often featured in school textbooks, the pivotal Photo 51, to the untrained eye, bears little resemblance to the 3-dimensional twisted ladder models of DNA, but visitors can always measure up against the enormous 3D model of our genetic material in the Welch Hall of Chemistry instead.

  1. Secrets

What happens in Area 51 stays in Area 51… the same could be said for the Museum’s offsite collections storage facility.


Holding millions of artifacts and specimens, the facility is full of treasures never before on display. For those select few who want to delve deeper into the secrets of HMNS, limited behind-the-scenes tours are available – if you dare!


Editor’s Note: Kaylee is the Project Manager/Data Analyst for Business Development and Budget at the Houston Museum of Natural Science.

Deep Ancestry: Our Story

Anyone who is interested in family history, or anyone who has ever gone to a library or archive to undertake genealogical research knows that while the subject is an exciting one, the work can be tedious and the resulting picture often fuzzy.

This is where we stand with regards to family research writ large, that of modern humanity. To be sure, we have come a long way since we humans even became aware of the fact that we had a very long history, or a deep ancestry. Consider the day, now more than 180 years ago, when people went into a cave in Belgium and encountered remains later identified as belonging to a Neanderthal individual. Compare that against our current understanding of human evolution. How we got here is an interesting story and it is an interesting tale to relate,. Where we go from here is equally intriguing.

Here is part one: how did we get here?

Traditionally, we rely on three main sources of information when studying human origins, our origins. These sources are: the material remains of that past (including both fossil remains and man-made tools), genetics and comparative primatology. The latter refers to observation of current non-human primates and possible correlations between their habitat and behavior with the environment in which our ancestors once lived and their behavior. If there is one constant in the picture generated by these sources is that it is always being refined and updated. Such is the nature of scientific endeavor: it never stands still. Thankfully, our thirst for greater understanding is never slaked either. There is always more to investigate.

Material remains have been the backbone of paleoanthropological studies. After all, what could be a better illustration of human evolution than a fossil of an ancient ancestor, or a tool made by a distant relative of ours? By carefully plotting where these remains have been found, we can reconstruct a picture of human evolution, we can start to see where our earliest ancestors once arose, evolved and eventually migrated from. By studying their tools, we can see human inventiveness at work. At first this is a tediously slow process, but eventually we see it picking up pace to the point we are today: new gadgets developed on a daily basis.

For a while, as people were studying fossil human remains, others were investigating genetics. However, initially the practitioners of these two pursuits did not know of each other’s work, or, did not realize how their work could benefit from the other person’s insights. And so we see how Mendel and Darwin were contemporaries, but their respective scientific insights and breakthroughs did not cross over and inspire the other.

DNA rendering
Creative Commons License photo credit: ynse

Our genetic makeup is the result of millions of years of evolution.

Since the Human Genome Project was completed in 2003, we have learned a lot about our genetic makeup. Since then, the chimp genome, gorilla genome, and the orangutan genome have been finished; by the way, the latter was sequenced in our own backyard here in Houston. This provides a nice platform to start comparing our genetic makeup with that of our close primate relatives, and find out where we differ, and, more interestingly, how similar we are below the surface. It turns out we are quite similar.

The difference 1% makes.

Differences, no matter how ostensibly small, remain important. One can be in awe about the fact that we share around 99% of genes with chimps. One could also turn that around and say “See how much difference 1% makes?” That difference, in turn, may help us figure out when in time we started to go our own way, after the split from a common ancestor. This is where the notion of a molecular clock comes in. This concept has been used to “to investigate several important issues, including the origin of modern humans, the date of the human/chimpanzee divergence, and the date of the Cambrian explosion.”

Thus we see in the literature that orangutans, with whom we share around 97 % of our DNA, split from the family tree around 16 to 15 million years ago. Humans and chimps became their own branches on the family tree around 6 to 5 million years ago.

As one researcher recently put it: “There remain signals of the distant past in DNA, and our approach is to use such signals to study the genetics of our ancestors.”

The concept of the molecular clock continues to be refined as our understanding of its potential and limitations has grown. For better or worse, however, it provides us with a tool to help situate major branching events on the family tree. This brings us to our own immediate past, our place in history, when modern humans appeared on the scene.

Modern Humans

Discoveries made in East Africa date the emergence of modern human beings to about 200,000 years ago. Two skulls, found in 1967 in Ethiopia were recently identified as the earliest known modern humans. While that makes all of us Africans, it data from mitochondrial DNA have suggested that our ancestors did not make it out of Africa until 60,000 years ago. The archaeological record seems to disagree, however. Man-made tools twice that age have recently been found in the Arabian Peninsula.

It is at times like these, when dates provided by genetics and archaeology diverge, that we hear voices criticizing the invalidity of this approach. What we will see happen, however, is that this apparent disjunction between two sets of data, will spur on researchers to find where the source of this disparity lies and resolve it. Were that to be impossible then we would have to go back to the drawing board and rethink our ideas about human evolution and the timing of critical events related to it.

Now for part two: where do we go from here?

As people become more mobile, we are now finding our mates much further away than we did just a few generations ago. This means that it will become more difficult to check that box on the census form asking for our ethnicity. It also means that we are slowly becoming more homogenized. Indigenous cultures are disappearing and language follow suit.

To get an idea of how exhilarating and mind-boggling this pursuit of science can be, I would like to invite the reader to attend an upcoming lecture.

On March 7, the Houston Museum of Natural Science will host Dr. Spencer Wells, lead scientist of the Genographic Project.

His lecture, entitled “Deep Ancestry: Inside the Genomic Project,” is brought to us by the Leakey Foundation. Dr. Wells is an Explorer-in-Residence at the National Geographic Society and Frank H. T. Rhodes Class of 1956 Professor at Cornell University. Dr. Wells will share with us how the Genographic Project, using data from hundreds of thousands of people, including members of the general public, the Genographic Project is deciphering the migratory routes followed by early humans as they populated the Earth.

I look forward to this lecture, and hope to see many of you at the museum that evening.

In the meantime, a pop quiz.

Q: What do the following individuals have in common?

Brazilian indian chiefs, Kaiapos tribe, during a collective interview.
Left to right: Raony (state of Mato Grosso), Kaye, Kadjor, Panara (Pará)
Creative Commons License photo credit: Valter Campanato, Agência Brasil (ABr). April 17, 2005
Ethiopian Orthodox Christian woman – Lalibela, Ethiopia
Creative Commons License photo credit: Dirk Van Tuerenhout
Lake Titicaca – Uros people
Creative Commons License photo credit: Dirk Van Tuerenhout

A: They are us. We are them. This is us.

Human evolution: the year 2010 in review (Part 1)

That’s some good-looking gombo, cher!

Creative Commons License photo credit: Southern Foodways Alliance

This blog contribution aims to be like a good Louisiana seafood gumbo: thick, hearty, spicy, and made up all kinds of finger-licking ingredients (pun intended). There will be some French, which would be apropos, some Latin as well, and all kinds of discoveries related to human origins, as they transpired this past year. I will follow up with a second part in a week or two with an observation and a comment.

In an earlier blog, “A pinky’s promise,” I wrote about the incredible discovery that was made early in 2010 when DNA analysis was performed on one small finger bone retrieved from a cave in Southern Siberia. The bone dated to a period (50,000 to 30,000 years ago) when all scientists assumed that the only living humans were either Homo sapiens sapiens or Neanderthals (perhaps we should now be saying Homo sapiens neanderthalensis, but I am getting ahead of the game). This first assumption proved to be wrong.

Entrance to the Denisova Cave
Creative Commons License photo credit:ЧуваевНиколай

In 2008, DNA analysis carried out on a single finger bone revealed that there was a third species of human walking the earth at that time. Toward the end of 2010, this view was corroborated by additional DNA analysis of a few teeth that were found in the same Denisova cave. The Max Planck Institute in Leipzig announced that these so-called “Denisovans” represent a new species.
More interesting still, some of their DNA is still around: the “Denisovans” interbred with the ancestors of Melanesians. This implies that at one point, this third species was quite widespread in Asia. If these conclusions hold up, the lesson we should take away from this breakthrough is that every little scrap of evidence counts when studying human origins, even a single tooth, or a finger bone. I wonder how many single finger bones or teeth have been overlooked in the past, or are still awaiting re-discovery in a museum drawer somewhere.

Neanderthals were also in the news this past year. For years, researchers have been vexed by questions such as “Who were these people?”, “Where did they come from?”, “What made them extinct?” and last but not least “Is there a little bit of Neanderthal in (some of) us?”

With regard to the last question, also discussed in earlier blogs, the way in which we answer that question will result in a different scientific (read: Latin) nomenclature for Neanderthal. Allow for the possibility of interbreeding between Homo sapiens and Neanderthals and also agree that their offspring was fertile, i.e., they successfully reproduced, then you would have to refer to Neanderthals as Homo sapiens neanderthalensis. If you disagree with this idea, and think it was unlikely these two populations interbred, or that their offspring was not capable of producing fertile offspring, then you would have to refer to Neanderthals as Homo neanderthalensis. This classifies them as a species separate from modern humans; by definition, species cannot interbreed and produce fertile offspring.

A Happy Neanderthal
Creative Commons License photo credit: erix!

The latter way of thinking was long popular among paleoanthropologists. Now the pendulum is swinging the other way. Scientists at the institute decoded the Neanderthal genome and compared it with that of modern humans. The result? In their words: “By comparing that genome with those of various present day humans, the team concluded that about 1 percent to 4 percent of the genome of non-Africans today is derived from Neanderthals.”  In people speak: up to 4% of a European’s genetic makeup could be inherited from the Neanderthal lineage, now extinct.

Before you check for hair on your knuckles, thank (or blame) a single finger bone and a few teeth, as well as the staff at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany for all this.

Lest we all (well, at least those of us of European descent) break out in hives and run for the nearest hills, scientists were quick to add: “[T]he Neanderthal DNA does not seem to have played a great role in human evolution.”

Certainly, 1 to 4% overlap in genetic makeup is not very much, but it is a whole lot more than we were willing to consider just a year ago. Differences between Homo sapiens sapiens and Homo sapiens neanderthalensis remain significant. The overall physical appearance of a modern human is very different from that of a Neanderthal. In terms of behavior, and cognitive abilities, the two subspecies also appear to be a world apart, never mind they shared portions of our planet.

Comparing Neanderthals and modern humans
One of the areas in which there were both similarities and differences was diet. These insights also came out this past year.  Did you know that Neanderthals ate their veggies? And that they liked to cook them as well? Perhaps you did. However, did you also know that they were not averse from eating each other?

Check back next week to see more on this, when Dirk discusses teeth, DNA, and his own conclusions to 2010 in review.

Silk Road Q&A with Curator Dirk

Last month we did an online Q&A with our curator Dirk Van Tuerenhout on our new exhibition, Secrets of the Silk Road. Visitors to this free event were able to ask Dirk questions about the mummies and other unique artifacts currently on display at HMNS. The questions and answers are listed below (the subject is bolded, the questions are italicized, and the answers are in plain text.)

Details of Mummies
How many mummies are in the show? How many mummies were found in this area?

Photo courtesy of Mu Xinhui.

There are two mummies in the exhibit. One is that of an adult woman. She lived around 1,800 – 1,500 BC and her remains were found in the Xiaohe (Small River) cemetery. The second mummy is that of an infant, sex unknown, who lived during the 8th century BC. This infant was found in Zaghunluq, several hundreds of miles removed from the Xiaohe location.

In their book, The Tarim Mummies, Mallory and Mair estimate that the number of known mummies is “on the order of 500” (pages 179-180).

What are the average length, height and weight of the mummies discovered?

This is a hard question to answer. A good example as to why this is so can be found at the museum: we have an adult woman and a child less than a year old. There is quite a difference in height in these two individuals. In terms of weight, I do not know if anyone has weighed them.

Life of Mummies
What languages do you think they might have spoken?

Interesting question, and difficult to answer. We should take note of the great number of languages that at one point were spoken and written in the Tarim and Turpan Basins. For example, when the Berlin Ethnological Museum unpacked the materials that they had excavated in the years 1902 – 1914 in the Tarim and Turpan Basins, they announced that they had evidence of 17 languages recorded in 24 different scripts (Mallory and Mair, The Tarim Mummies, p. 102).

Who first found the mummies, was any “looting” involved, and how many have been found so far?

Knowledge of the cemeteries containing mummies goes back many centuries, as does evidence of looting. The latter activity has continued until today, sad to say. In terms of who first alerted the outside world to the existence of these mummies, there are European and American researchers who worked in the last decade of the 19th century and the first decade of the 20th. People like Aurel Stein of the Smithsonian, and the Swedes Sven Hedin and Folke Bergman, just to name a few, explored these remote areas and encountered mummies. While they made note of their existence, they did not undertake scientific studies, partly because their initial research focus was a different one, and partly because of the logistics involved. Most often the mummies were excavated, photographed and then re-buried. In all we know of about 500 mummies. There must have been many thousands more that once lived and were buried.

What is the fortification-looking area in the slide show, and where is it located? Are those the remains of boats around it?

Photo courtesy of Mu Xinhui.

The fortification-looking area is in fact a cemetery. What looks like a palisade is a series of wooden poles found marking the cemetery. A coffin often used in this cemetery is one called a “boat coffin,’ because of its apparent similarity with a small boat. They never served as a boat, as one can easily observe when looking at a boat coffin currently on display at the museum.

Were there writings in tomb objects? Tokens of religious or religion?

Texts were found in the tombs dating to the period when the Silk Road was in existence ( 138 BC – 1368 AD). We now of 17 languages written in 24 different scripts; most of the evidence for these comes from funerary contexts. However, the mummies on display at the museum are prehistoric, date to the period before the Silk Road opened up. They were not found with “letters in their pockets.”

What weapons were found?  Composite bows?

The period covered by the exhibit is quite extensive, going from 1,800 BC through the 14th century. References to and information about weapons abound during these three millennia. For example, arrows and arrow heads have been found in various cemeteries, including Xiaohe and Kucha. As far as the presence of composite bows is concerned, I came across a paper by Andrew Hall and Jack Farrell originally published in The Society of Archer-Antiquaries, #51, 2008, pp. 89-98. It discusses composite bows found in the Tarim basin. (You can find an online version of this paper here). Composite bows have also been linked with Subeshi.

Photo courtesy of Mu Xinhui.

What are the materials of the clothing and ropes made of?

Clothing ranges from woolen cloaks, fur boots, to silk robes. I do not have reliable information on the ropes.

How close is the clothing to Celtic clothing of the same period?

Here is a passage from Mallory and Mair, The Tarim Mummies, that you will find interesting (pp. 217 – 219):

“Although dating to the same period as Zaghunluq, the cemetery at Qizilchoqa to the northeast near Hami yielded different weaves for which far-reaching historical connections have been suggested. The precise date of the Qizilchoqa cemetery is problematic: the initial dates place it at about 1200 BC, contemporary with the later period of the Yanbulaq culture, but a new radiocarbon date of c. 800 – 530 BC suggests that it belongs to the later Tort Erik (Sidaogou) culture. The abundant evidence for dress here revealed a variety of clothes, including woolen robes with colored belt bands and fur coats (the fur turned inside) with integrated gloves, which fastened with wooden buttons. But our main story lies with the woolen textiles.

Irene Good made a detailed examination of a textile fragment (15 cm by 19 cm – 6 in by 4 in) from the site. The main here was normal diagonal twill, but the decoration involved the production of plaid, the same type of decorative technique one might expect on a Scottish tartan. This involved the wide and narrow color strips on both the warp and the weft and here the colors employed were threads of blue, white and brown, each thread made up of some 30 to 40 fibers. The white and brown thread are natural the blue thread is dyed. This small strip of cloth has been invested with heavy historical implications.

The earliest twills known derive from the region between Turkey and the Caucasus where they were dated to the late 4th – 3rd millennium BC, and they are found in abundance from the late 2nd millennium BC in Europe, particularly at the site of Hallstatt. Here miners left residues of their clothing (and, occasionally, themselves) in the protective environment of Austrian salt mines. As the Hallstatt culture occupied a territory which classical authors would associate with Celts only a few centuries later, it is generally presumed that the miners here (and the warriors and others buried in the neighboring cemetery) were also Celts or proto-Celts. The easternmost finds of twill, dating from the centuries around 1000 BC (or somewhat later), are the fragment from Qizilchoqa and many others like it from the same cemetery (some very Scottish looking); true twills are unknown in China until well into the 1st millennium AD. The Qizilchoqa twill is virtually identical to the textile fragments recovered from Hallstatt with respect to both style and technique (hence one of the arguments employed by the tabloid press for placing kilted Celts in the Tarim Basin). We are not talking simply of the diffusion of a particular weaving and color pattern. As Elizabeth barber writes: “the regular combination of plaids and twills n the same cloth and the similar play of wides and narrows in the plaids moves us into a border zone where it’s harder to imagine the sum total as accidental.” There is also a similarity in the weight of the cloth. Of course there are differences between the Hallstatt and the Qizilchoqa materials, for example, Hallstatt employed only two colors while the Qizilchoqa plaids used from three to six colors. In addition, there are even differences among the Tarim plaids. Irene Good has noted that the weaving traditions of Zaghunluq and Qizilchoqa are themselves considerably different even though they both ate to the period before the middle of the first millennium BC. The Qizilchoqa (Hami) fragment appears to derive from a hairy rather than a wooly fleece and would seem to come from a different breed of sheep than that found at Zaghunluq; there are also differences in the crafting of the cloth, e.g. the Zaghunluq twill involved hopping over three stems of the warp rather than the more typical two as found at Qizilchoqa. In weighing the similarities between the European and East Central Asian material, Barber concludes that the two are related yet also makes it clear that neither is derived from the other. How do we connect the two textile traditions?

Elizabeth Barber has deduced that the twill plaid recovered from the northern Tarim may be placed within the context of Indo-European migrations. As we have already recounted, one of the most popular theories of Indo-European origins would locate their homeland in the steppelands encompassing Ukraine and southern Russia, a region which would have been in direct contact with the Caucasus whence we obtain some of our earliest evidence for twills. In this model, the earliest Indo-Europeans would have known plaid and carried it west into central and western Europe where it would later emerge among the Celts of the Hallstatt culture; it would also have been carried eastward across the steppe where it would have been introduced by Indo-Europeans, here identified as the Tocharians, into the Tarim Basin.”

How do you keep the mummies preserved while they are on display?

We maintain a constant temperature and humidity within the museum and the exhibit hall.

Are these mummies considered to be the best preserved in the world?  Even better than the Egyptian mummies?

They are among the best preserved mummies in the world. This makes them stand out, not only for this reason, but also because these individuals were mummified by nature rather than by human agency.

What role did the climate play in preservation?

Climate and the environment were the main reasons some of the remains became mummies. The best preserved mummies tend to be dressed very warmly. This has led archaeologists to suggest that these individuals died in the winter. Their bodies would then have been freeze-dried first, then cooked and parched during the summer. If any moisture was left in the bodies, that would have been removed by the minerals present in the desert. The rivers descending from the mountains carry lots of minerals.

Were both the Y chromosome and Mitochondrial DNA analyses done on the male mummies?

My understanding is that they were not. mtDNA analysis allows one to retrace the lineage of the individual studied through the maternal line. While it would connect a male to his female ancestors, it would not provide a link with his descendants, since none would have inherited his mtDNA.

 Creative Commons License Photo credit: Wang Da-Gang

Is the baby linked by DNA to the woman?

The baby is about 1000 years younger and was buried in a cemetery about 250 – 300 miles away from that where the woman was found. They were not immediate family. They could be distant relatives like you and I would be.

Have studies been done to determine where the mummies were born or grew up? Are they all considered to have been born and raised where they were found?

That type of study is referred to as isotopic analysis and it can tell us where a person grew up. To the best of my knowledge this has not been done yet on these mummies.

Has any testing been done in the region to determine if the Y chromosome markers from the male mummies are present in the living population?

In paper published in early 2010, we find that Y chromosome research was carried out of seven male individuals from the Xiaohe cemetery. The paper is available online in open access format at the time of writing this reply. (Go here.)

The researchers state (p. 6): “The Y chromosome haplogroup of the seven males were all assigned to haplogroup R1a1a through screening the Y-SNPs at M89, M9, M45, M173 and M198 successively. Haplogroup R1a1a is widely distributed in Eurasia: it is mainly found in Eastern Europe, Central Asia, South Asia, Siberia, ancient Siberia, but rare in East Asia.”

In other words, the Y chromosomes found in the Xiaohe mummies were compared with those found in contemporary male populations world-wide. I do not know if in that sample, males from the Tarim Basin were included.