Why Do Young Earth Creationists Only Know Of Lucy?

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Adam Benton from EvoAnth has published an interesting paper where he tries to understand why Young Earth Creationists are consistently ignorant of other fossil hominids. To help answer his question, he analyzed how three prominent creationist websites are represent the hominin fossil record. Benton searched for mentions of five other hominid species that are just as important as Lucy and ideally should be represented just as in-depth. The results of his study are shown in the table below. It shows how many times these websites refer each of the fossils under consideration. You can clearly see the bias they represent.

Ta b l e 1. The number of pages from the ICR, AiG, and CMI websites discussing each of the  fossils under consideration.

Ta b l e 1. The number of pages from the ICR, AiG, and CMI websites discussing each of the fossils under consideration.

His conclusions:

It is apparent that Answers in Genesis (AiG), the Institute for Creation Research (ICR), and Creation Ministries International (CMI) are presenting a distorted view of human evolution, glossing over critical fossils and creating the false impression that there is little evidence for human evolution. In fact, the evidence is voluminous.

I do not mean to argue that this distortion is intentional deception; writers at these organizations may simply be unaware of the vast majority of paleoanthropological literature, or perhaps prefer to discuss Lucy, as it is the example with which they are most familiar.

Regardless of the ultimate cause, the end result is clear: people who rely on AiG, CMI, and/ or the ICR for information on human evolution will wind up woefully underestimating the hominin fossil record.

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Integrating Health

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When dealing with the term “medicine,” there is no single definition, static through space and time.  Many of the world’s medImageical systems illustrate diverging, sometimes opposing, stories of health and healing, and each culture invariably believes in its own medicine.

Unfortunately, our globalized world has been slow to recognize the medicine of the “other.”  Last month the Prince of Wales was dismayed by delay tactics of the government in creating a register of healthcare practitioners that would include alternative, complementary, and holistic professionals alongside their biomedical counterparts. On the heels of widening usage of complementary healthcare, Prince Charles has advocated regulation and evaluation of alternative routes to health beyond those readily sanctioned by the state. However, the plan set out two years ago to create a more inclusive register of healthcare services has yet to be implemented. Such a register would ensure regulation of herbal, Chinese, and other alternative medical practitioners that would elevate both safety and access.

Reluctance to include alternative medicine in standard healthcare evaluation compromises the safety of patients. Similar problems with regulation have been found in the herbal supplement industry, where a lack of oversight has resulted in false advertising of ingredients, and occasionally the addition of harmful substances.

Recently, researchers published a study about the benefits of Chinese medical treatments in preventing diabetes. The findings in The Journal of Clinical Endocrinology & Metabolism showed that the herbal mixture Tianqi lowers the risk of developing Type 2 diabetes among individuals with damaged glucose tolerance. Medicine like Tianqi may represent logical alternatives or additions to pharmaceutical treatments, and it is research and regulation that will allow patients to benefit.

There are models of integrated medical treatment already in place, and we can learn much from the long road that converging medical systems took to reach this meeting point. In Bolivia, many patients initially avoided the primary healthcare clinics that arrived asserting biomedicine’s authority on all matters of well-being (see Joseph Bastien’s book Drum and Stethoscope: Integrating Ethnomedicine and Biomedicine in Bolivia). Those who did visit the alien doctors described the treatments as ineffective, and for all intents and purposes the patients did not improve. Thus biomedicine was dethroned in rural Bolivia.

There is a cultural component to this phenomenon. At first, a pre-natal tetanus vaccination campaign failed completely when the foreign doctors and nurses brandished their vaccines and claimed panacea. The local and indigenous communities had ideas as concrete as the biomedical gospel of the doctors—they believed the primary cause of tetanus to be malignant spirits and not microscopic pathogens. Furthermore, mistrust abounded as healers and shamans questioned the purpose of such “vaccines.” It appeared as though the doctors were stealing precious “fat” with these contraptions, “fat”embodying a source of life and health for people in this region. Nobody imagined that the primary health clinics would fail, but as the doctors distanced themselves further and further from the people, insisting on the infallibility of their views and the archaic beliefs of the villagers, the doctors and their sterile, white lab coats were alienated entirely.

It was not until later, when the doctors engaged a dialogue with local healers and shamans, hiring them as equals in the health clinics, that more and more infants lived past the first few weeks of life. Today many Bolivian health clinics host biomedical doctors and nurses, community healers, herbalists, and even shamans in a network of healthcare support that caters to the individual, instead of the preferences of the few who create the healthcare guidelines. The results have been impressive, boasting overall improvement in community health. Health is complex set of physical, psychological, and cultural processes, and therefore, the efficacy of treatment is not based solely on cut and dry pathology but also personal background, beliefs, and attitudes toward the healthcare itself.

How does this relate outside Bolivia? The integration of complementary and biomedical approaches to healthcare can produce optimal results in patient health. The individual comes from a wide variety of experiences and world views, all of which influence response to treatment and consultation. Moreover, there are methods from diverse medical systems that are gaining widespread acceptance.

Through regulation of all of these different options for safety and efficacy, healthcare can be more than a mass product—a finely tailored treatment, fitting like a glove around every inflammation and concern. Perhaps it is time to clear away the delay tactics and move toward the formation of a healthcare system that heals the individual, not the system.

By Natalia Magnani

Video

Dr. Yonatan Sahle and the African Origins of Human Intelligence

yonatan-sahleDr. Yonatan Sahle now holds the Glenn Isaac Postdoctoral Seat in the Human Evolution Research Center at UC Berkeley. He recently gave a talk at my alma mater on the African Origins of Human Intelligence at CSU East Bay. You all may know that our early ancestors diverged from sub-Saharan populations approx 100,000 – 250,000 years ago. Our technology during this transition was prolific. Dr. Sahle discusses this, along with what he has recently found, the earliest projectile points in the worldHis entire talk is listed above…. Take time to check out this excerpt from the Q&A session where he schools a racist commenter.

Sahle Y, Hutchings WK, Braun DR, Sealy JC, Morgan LE, et al. (2013) Earliest Stone-Tipped Projectiles from the Ethiopian Rift Date to >279,000 Years Ago. PLoS ONE 8(11): e78092. doi:10.1371/journal.pone.0078092

Oldest Hominin Footprints Found Outside of Africa

The Laetoli hominin footprints have finally met their match. A group of footprints dating between 850,000 and 950,000 years ago were reported in coastal Happisburgh, the United Kingdom, as seen in a publication in Plos One today. The work was headed by Nick Ashton of the British Museum.

Laetoli Footprints, Tanzania

Laetoli Footprints, Tanzania. Photo by Tim Evanson

Footprints are rarely preserved prehistorically—their survival generaly requires just the right level of moisture and sediment composition, followed by a low-energy depositional context to gently cover the impression. In fact, before this the oldest known footprints in Europe were approximately 350,000 years old, hailing from a steep slope in Italy. After this the record is again sparse, until we find a single footprint dated to between 97 and 63 thousand years ago in Romania, likely that of a Neandertal. The oldest hominin footprints are found in Tanzania, and date to 3.6 million years ago (attributed to A. afarensis).

The reported age of the geological layers exceeds the date of the oldest site in the region by 350,000 years, pushing back known human occupation in Northern Europe significantly. A number of individuals are represented by the imprints, and based on size ranged from juvenile to adult. Like us, these hominins had a big toe that pointed forward, and arched feet. It is possible that they were made by a species similar to Homo antecessor, a species known from the Spanish site of Atapuerca .

Happisburgh hominin footprints.

Happisburgh hominin footprints, from Ashton et al. 2013.

The researchers approximated the height of individuals in the group to be just below one meter, to 1.73 meters tall based on foot size to stature ratios.  These estimates were based on the size of 12 relatively complete footprints, ranging from 14-16 centimeters.  However, at least 49 footprints seemed to be present at the location.

Unfortunately due to the erosional context of the find, the footprints were obliterated by the sea within a month of their discovery in May 2013. However, casts and photogrammetric models were constructed prior to their natural destruction for future study.

I’ve been scratching my head since reading the article though—for such an important find, was it not possible to cut them out of the ground and remove them to a museum? The slab was reported to be 12 square meters, and you’d think that researchers would’ve gone to great lengths to preserve the originals at least partially. Maybe next time an invaluable slab of ancient hominin footprints erodes out of the shoreline they’ll be ready?

Matthew Magnani

Bill Nye takes on Young Earth Creationism

Yesterday, young earth creationist Ken Ham hosted household name Bill Nye at the Creation Museum to “debate” evolution. See the recording here. Bill_Nye

I first heard about the Nye Ham event a few weeks ago, and was at first perturbed with Nye that he would enter into such an exchange.  I side more with Richard Dawkins (on this one), that entering into any kind of discussion with creationists lends some sort of validity to their perspective, which can usually be cured with a heavy dose of education.

Last night I tuned in for about an hour of the talk, and heard two men speaking past one another for most of the time. On one side you have a young earth creationist and seasoned debater. On the other was Nye, a relatively inexperienced debater but a strong advocate of accurate, scientific education.

After the show, Buzzfeed wrangled 22 creationists with a pad of paper and a pen. The object of the exercise was to send messages to those who believe in evolution (see our next post “22 messages to people who believe in gravity”).

Most of the creationists had self-satisfied smiles, but all had fundamental misunderstandings of evolution.  My favorites revolve around the origins of humans—in fact, there were two comments made directly about Lucy. However, I threw in another quote, on the sunset, for good measure.

Quotes are direct including any errors.

“If we came from monkeys then why are there still monkeys?”

“There is no in between… the only one found has been Lucy and there are only a few pieces of the hundreds necessary for an “official proof.”

“How do you explain a sunset if their is no god?”

I highlight the first two quotes because of their direct relevance to anthropology.  The first, asking why there are still monkeys, fundamentally misunderstands the process of evolution at its most basic level. The second respondent ignores the entire field of paleoanthropology, which expands exponentially every year with new discoveries.

I agree with Nye’s main point– the only way to fix misconceptions like these is through improving science education. After seeing blatant misunderstandings of simple evolutionary concepts, I am reminded how impossible it is to argue with the misinformed. While I’m not positive what the impact of the debate will be yet, I am hopeful that bringing the issue front and center for a little while will be positive.

By Matthew Magnani

News on South Africa’s Hominins: Berger’s Rising Star Expedition

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This November, a team funded by National Geographic and led by Lee Berger of the University of Witwatersrand in Johannesburg made a huge find. 1200 hominin skeletal elements were recovered from a South African cave, representing at least 12 individuals. Human remains are pretty rare, and this one site contains more human fossil material than the rest of South Africa combined, according to Berger.  While I’m sure the researchers have their hunches, they have so far been cryptic about species attribution. Dates have also yet to be determined for the collection.

Only months passed between the original discovery of the cave and the excavation of the remains. Berger quickly mobilized a 60 person team and secured funding from National Geographic to conduct a field season (the team came to be called the Rising Star Expedition). Though the remains had been in the cave for perhaps millions of years, it was impossible to know if they would survive another rainy season, which was fast approaching in November.  Unlike most other fossils of the same antiquity these were sitting in loose sediments, which are easier to excavate than breccia but could likely make the bones more fragile.

In order to access the chamber with the fossils, scientists must squeeze through a seven inch opening.  While it has been suggested that the cave opening be widened, Berger doesn’t think a cave that has been forming for millions of years should be updated so that the project directors can stand over the finds. For this reason, small-bodied paleoanthropologists and archaeologists were recruited from all over the world to participate in the fieldwork. In fact, because of size, Berger sent his 15 year old son Matthew in to verify there were in fact human remains in the preliminary stages of the project.

Lee Berger with A. sediba. Photo credit Eloff.

Lee Berger with A. sediba. Photo credit Eloff.

While the finds coming from this project are remarkable, the way in which Berger has been directing the project has been equally fantastic. Typical fossil finds (see recent post on Ardi, for an example) are guarded for years, sometimes over a decade. Frequently only select researchers are able to access the material and data, which makes it difficult for publications to be critiqued or built on by other scientists.  Berger has gone the opposite direction, making fossils less his and more open-access. He already set the stage for this type of protocol with A. sediba, which was published in 2010 shortly after being unearthed.

Transparency and collaboration wasn’t enough for leaders of the Rising Star Expedition, though. Last week, they announced a call for applications to work on the fossil material, especially for early-career scientists.  Successful applicants will have their expenses covered to travel to South Africa for the month long project, which is guaranteed to generate some high-impact publications.  This type of cooperative research is unheard of, and will provide significant opportunities for future generations of paleoanthropologists.  If I didn’t specialize in stone tools, my application would’ve already been in.

The work of Berger’s team is commendable, and they will undoubtedly out produce most other proprietary, territorial paleoanthropologist in both quantity and quality. It will be interesting to see what else the cave yields next season, since literally only centimeters on the surface of a relatively small area have been scratched.

Matthew Magnani

Ramidus Returns

Ardipithecus ramidus (Ardi) is back. In 2009, the skeleton discovered by Tim White’s team in the mid-90s was published in full. Dated to approximately 4.4 million years old based on volcanic stratigraphy, ramidus was found in the Middle Awash river valley in Ethiopia. The most complete individual, over 40% of a female skeleton, had the brain approximately the size of a chimp and exhibited a similar level of facial prognathism. Hand and foot morphology pointed to an arboreal creature, most notably a divergent big toe that would make many primates proud.

However, ramidus exhibits a bunch of other traits which seemed derived in the direction of Homo, which is what the authors of the study are pushing. These traits include reduced canines, and aspects of the foot and pelvis which could indicate a level of at least facultative bipedalism.  Critics argue that it is possible that these traits were present in many apes of the time period around the human-chimp split, and that chimps rather than humans moved away from these adaptations.

Ardipithecus ramidus from White et al. 2009

Ardipithecus ramidus from White et al. 2009

The new study published in PNAS furthers the original argument made by the discoverers that Ardi is in fact a hominin.  In particular, the reconstructed basicranium was observed in the study, led by William Kimbel of Arizona State University. Kimbel and his team demonstrate that like Homo and Australopithecus, Ardi had a short basicranium, and a relatively anteriorly placed foramen magnum. The placement of the foramen magnum, in particular, is particularly important in determining whether or not a species was bipedal. Along with the broadening of the cranial base, came notable modifications/shifting of tympanic elements and other foramena.  In short, the authors put forward the argument that because of the age of ramidus, it is possible to say that these types of changes in the cranial base were some of the earliest derivations towards Homo.

Paleoanthropologists are in a tough place. Inferring descent through morphology alone is tough, but it is all fossils really give us right now. This was just demonstrated in an even more recent case where H. heidelbergensis was demonstrated to be more closely related to Denisovans on its matriline than Neandertals, with whom they shared many morphological affinities. Going back millions of years doesn’t make it any easier, and we’re not going to be recovering 4.4 million year old DNA any time soon to help give answers. Till then here’s to the many personalities of paleoanthropology, who direct our understanding of human evolution with biology, anthropology, and sometimes a sprinkling of ego.

Matthew Magnani

A Higher Than Average Risk Of Diabetes Among Mexicans Linked To Neandertal Introgression

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Why do some populations have increased incidences of chronic disease? Why do blacks have hypertension more than whites? Why does a Mexican have 2.72 more the risk of having Type 2 Diabetes compared to a non-Hispanic person? A new paper published in Nature yesterday outlines a particularly interesting finding about rhetorical questions about metabolic disease… One that I’ll digest in this post.

David Altshuler and his colleagues conducted a GWAS comparing 8,214 Mexicans and other Latin Americans. They specifically had 3,848 people with type 2 diabetes and 4,366 non-diabetic controls. They compared over 9.2 million SNPs. They found a unique SNP, SLC16A11, that codes for a transmembrane transporter of monocarboxylates and triacylglycerols.

Graphical depictions of SLC16A11 haplotypes constructed from the synonymous and four missense SNPs associated to type 2 diabetes, with haplotype frequencies derived from the 1000 Genomes Project and SIGMA samples. AFR, African (n = 185); ASN, east Asian (n = 286); EUR, European (n = 379); MXL, Mexican samples from Los Angeles (n = 66). Frequencies from SIGMA samples are calculated from genotypes and represent either the entire data set (All) or only samples estimated to have ≥95% Native American ancestry (≥95 NA, n = 290; Supplementary Methods). Haplotypes with population frequency <1% are not depicted.

Graphical depictions of SLC16A11 haplotypes constructed from the synonymous and four missense SNPs associated to type 2 diabetes, with haplotype frequencies derived from the 1000 Genomes Project and SIGMA samples. AFR, African (n = 185); ASN, east Asian (n = 286); EUR, European (n = 379); MXL, Mexican samples from Los Angeles (n = 66). Frequencies from SIGMA samples are calculated from genotypes and represent either the entire data set (All) or only samples estimated to have ≥95% Native American ancestry (≥95 NA, n = 290; Supplementary Methods). Haplotypes with population frequency <1% are not depicted.

The authors found that why Mexican Americans are twice as likely to develop type 2 diabetes is because about 50% of the population carry the four amino acid substitution risk haplotype. In comparison, 20% of Asians have it, only 2% of Europeans carry the mutations, and no Africans. The risk for Type 2 diabetes for a Mexican increases from 13% to 19% if they inherit two copies of the mutations, but others the risk only increases to about 11% from 8%. They tend to carry this one sequence of DNA more than people with only African or European ancestry.

Why and where did this increased frequency of SLC16A11, come from? The haplotype sequence is highly divergent, with an estimated TMRCA of 799,000 years to a European haplotype. This date long precedes out of Africa but yet it’s not observed in Africa and rare in Europe. When the authors compared it to the published Neandertal genome and the Denisova genome, they found no similarities.

Denisova Pedal Phaylnx

But when they compared it to the unpublished genome of the Neandertal from Denisova Cave they found that individual was homozygous across 5 kb for the 5 SNP haplotype at SLC16A11, including all four missense SNPs, outlined above. This indiciates that the risk haplotype introgressed into modern humans via admixture with Neandertals.

The impact of Neandertal introgression is now well-known. Up to 4% of our genomes, for those of us who are non-African, have Neandertal sequences in them. Does this mean that Mexican’s have more than the average admixture? No. The authors write, 

“We note that whereas this particular Neanderthal-derived haplotype is common in the Americas, Latin Americans have the same proportion of Neanderthal ancestry genome-wide as other Eurasian populations.”

We know obesity and diabetes are two epidemics that are hand in hand. As SLC16A11 codes for a protein that transports lipids, any changes to its structure and function can change the amount of a type of fat which moves in and out of a cell. These findings suggest that some Mexicans and even Asians inherited a variant of SLC16A11 from Neandertals, which increases risk of type 2 diabetes.

A Fourth Unknown Early Human Lineage?

A couple of days ago, Nature published a comparison of the genome of a 50,000-year-old Neandertal woman with those of modern humans and Denisovans. The group revealed evidence of interbreeding among at least 4 species of early humans.

Family tree of the four groups of early humans living in Eurasia 50,000 years ago and the gene flow between the groups due to interbreeding. Image credit: Kay Prüfer et al.

Neandertals and Denisovans diverged 300,000 years ago, both of which eventually died out, they left bits of their genetic heritage because they occasionally interbred with modern humans. It is estimated about 1.5 – 2.1% of modern non-African’s can be traced to Neandertals and for Denisovans, only about 6% of Oceanic populations like aborigines, New Guineans, and about 0.2% of Han populations show footprints.

The genome comparisons show that Denisovans interbred with a mysterious, fourth group of early humans also living in Eurasia at the time. That group had split from the others more than a million years ago, and may have been the group of human ancestors known as Homo erectus, which fossils show was living in Europe and Asia at the time.

This current study also indicates that this female Neandertal was highly inbred. She was the daughter of a very closely related mother and father who either were half-siblings who shared the same mother, an uncle and niece or aunt and nephew, a grandparent and grandchild, or double first-cousins. Further analyses suggest that the population sizes of Neandertals and Denisovans were small and that inbreeding may have been more common in Neanderthal groups than in modern populations.

 

A New Twist in the Neandertal Lineage

Just in from Atapuerca, northern Spain: mitochondrial DNA has been retrieved from the bones of Homo heidelbergensis.

The Sima de los Huesos, or pit of bones, has been a treasure trove of human remains, and has yielded a minimum number of 28 individuals dating to at least 300,000 years ago. This type of preservation and concentration of human remains is rare—most excavations are lucky to turn up a stray hominin tooth every couple of seasons.

Homo heidelbergensis cranium number five from the Sima. Photo by José-Manuel Benito Álvarez

Homo heidelbergensis cranium number five from the Sima. Photo by José-Manuel Benito Álvarez

Not to mention mitochondrial DNA typically does not have such a long shelf-life. After a successful attempt at analyzing cave bear DNA from the Sima, researchers decided to risk portions of valuable human remains for testing. The MtDNA did turn out to be viable, and the provided some seriously unexpected results.

The Heidelberg femur that yielded the mtDNA. Image from Meyer et al. 2013.

The Heidelberg femur that yielded the mtDNA. Image from Meyer et al. 2013.

The outcome of the mtDNA analysis demonstrates that the Sima matrilineal tree shares its roots with Denisovan populations, a group of archaic humans discovered recently in Siberia. Previously it would have been expected that the Sima Heidelberg mitochondrial genome would share most affinities with Neandertals.

So what exactly does this mean for our current understanding of human evolutionary models?

The findings imply that the Sima hominins share a common ancestor with Denisovans rather than Neandertals. For a long time, the Heidelberg population of the Sima was looked at as a group of hominins en route to becoming Neandertals—now the picture isn’t as clear.

It is possible that the Sima hominins are a distinct line of humans that later contributed genetically to Denisovans. This wouldn’t however explain the morphological traits they exhibit which are consistent with Neandertals, and would mean the same traits evolved in two separate contexts.

It is also possible that the Sima population was ancestral to both Neandertals and Denisovans. This answer would require further explanation for why the genomes of Neandertals differ significantly from the recently sequenced genome, though.

Right now, there isn’t one answer.  As DNA processing methodology gets better and better, the picture of what was going on will become more evident. We’ve only begun to scratch the surface of what was really going on, and it’s going to get a lot more complicated before it gets any clearer.

Matthew Magnani

 

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