Friday, November 24, 2017

New Jebel Irhoud Date Causes Rethink of Chinese Dali Skull

Newsweek (Yes, that Newsweek) has a story on the reexamination of the Chinese Dali cranium, in light of the revised dates for the Jebel Irhoud skulls.  Kastalia Medrano writes:
Known as the Dali skull, it was discovered nearly 40 years ago in China’s Shaanxi province. It belonged to a member of the early hominin species Homo erectus. Its facial structure and brain case are intact, despite being dated to around 260,000 years ago. The Dali skull is so old that archaeologists initially didn’t believe it could share features with the modern Homo sapiens.

But Xinzhi Wu of the Chinese Academy of Sciences in Beijing believed that due to the overwhelming physical similarities, Homo erectus must have shared DNA with Homo sapiens. After decades of this idea being dismissed by mainstream academia, Wu and a colleague, Sheela Athreya of Texas A&M University, recently reanalyzed the Dali skull and found it may force us to rewrite our evolutionary history after all. It’s incredibly similar to two separate Homo sapiens skulls previously found in Morocco. “I really wasn’t expecting that,” Athreya told New Scientist.

If we’d found only the Moroccan skulls, and not the Dali skull, it would make sense to keep believing all modern humans evolved in Africa. But the similarities show that early modern humans may not have been genetically isolated from other parts of the world, like what we know today as China.

“I think gene flow could have been multidirectional, so some of the traits seen in Europe or Africa could have originated in Asia,” Athreya told New Scientist.
Okay, now the nuts and bolts.Dali has always been thought to occupy that rarified space between Homo erectus  and early modern Homo sapiens.  It was always thought to be between 200 and 250 kya, and optically-stimulated luminescence dating (a variant of thermoluminescence) places it between 258 and 267 kya.  My analyses of the skull suggested that it was, in no way, shape or form, a modern human but it did not tend to cluster with the Neandertals in terms of head shape.  Athreya and Wu have done an extensive multivariate analysis and conclude (from the article, likely behind a paywall:
When just the facial skeleton is considered, Dali aligns with Middle Paleolithic H. sapiens and is clearly more derived than African or Eurasian Middle Pleistocene Homo. When just the neurocranium is considered, Dali is most similar to African and Eastern Eurasian but not Western European Middle Pleistocene Homo. When both sets of variables are considered together, Dali exhibits a unique morphology that is most closely aligned with the earliest H. sapiens from North Africa and the Levant.

These results add perspective to our previous view of as Dali a “transitional” form between
Chinese H. erectus and H. sapiens. Athough no taxonomic allocation is appropriate at this time for Dali, it appears to represent a population that played a more central role in the origin of Chinese H. sapiens. Dali's affinities can be understood in the context of Wu's Continuity with Hybridization scenario and a braided-stream network model of gene flow. Specifically, we propose that Pleistocene populations in China were shaped by periods of isolated evolutionary change within local lineages at certain times, and gene flow between local lineages or between Eastern and Western Eurasia, and Africa at other times, resulting in contributions being made in different capacities to different regions at different times.
In combination with the Xuchang remains, the reanalysis of this skull suggests that, indeed, there is a long and complex interrelationship between different hominin groups that dates back some 400 thousand years. From the paper:
In the braided-stream network model, evolutionary change in China was the result of a shifting network of gene flow among distinct regional Chinese populations, as well as between Chinese and Western Eurasian populations. These were not isolated evolutionary lineages; gene flow both within China and between Eastern Eurasia, Western Eurasia and Africa was intermittent and could explain the similarities in aspects of the neurocranium found here between Dali and Western Eurasian Middle Pleistocene humans. Gene flow would best be described as a braided stream network with periods of isolated evolutionary change within a local lineage at times, and periods of gene flow between local lineages or paleo-demes at other times, resulting in contributions being made in different capacities to different regions at different times.
It is pretty clear that our simplistic models of Recent African Replacement and Multiregional Evolution need to be reworked. It is becoming more apparent that what we are looking at either a polytypic species with a huge geographical range or a syngamion of related species that intermixed regularly. The Xuchang skulls were, apparently, not unique.

Thursday, November 23, 2017

Flat Earth Convention in North Carolina

Nuts, I wish I could have gone to this. Stephanie Pappas, at Live Science writes:
A conference aimed at disputing the idea that the world is round just wrapped up in North Carolina.  The first-ever 2017 Flat Earth International Conference (FEIC) was held in Raleigh on Nov. 9 and 10, featuring some of the big names in round-Earth denial. Among the speakers were Darryle Marble, who once took a level on a plane to "prove" the Earth doesn't curve; Mark Sargent, the creator of the Flat Earth Clues YouTube Series, who believes all life is enclosed in a "Truman Show"-like dome structure; and Jeran Campanella, a YouTube and online radio personality, who makes flat-Earth, 9/11 Truther and other conspiracy theory videos. [7 Ways to Prove the Earth Is Round]
Apparently, it was quite a smorgasbord of conspiracy theoreticians.  It is always great fun to see how the science is twisted and one can never quite tell if they are serious or not. 

Wednesday, November 22, 2017

ID Supporter Has Wikipedia Page Erased

Okay, this is just snotty.  Günter Bechly is a palaeontologist who was at the State Museum of Natural History in Stuttgart, Germany.  Recently, Dr. Bechly came out in favor of Intelligent Design.  For this crime, he has had his Wikipedia erased.  According to David Klinghoffer, at Evolution and Science Today (used to be Evolution News and Views):
Our distinguished paleontologist colleague Günter Bechly was erased from Wikipedia after he came out as a proponent of the theory of intelligent design. That, in turn, was after he had already been pushed out of his curator role at the State Museum of Natural History in Stuttgart, Germany, for the same reason. The editors at Wikipedia obscured their treatment of Günter, a world-class expert on dragonflies, by claiming his heresy on ID had nothing to do with the decision to excise him. Instead, they innocently proclaimed that it was due to the realization that he isn’t “notable” enough for the online encyclopedia.

I’ve already pointed out the problems with this contention, and noted that the editors of Bechly’s page and of the grossly distorted Intelligent Design page itself make little effort to hide the ideological axes they grind. There’s little mystery about what happened to Dr. Bechly, or to another ID advocate, Walter Bradley at Baylor University, whose Wiki entry was shredded to near nothing. This is one way the scientific consensus on evolution is maintained, by threatening dissenters. For a scientist, having your accomplishments erased is the ultimate punishment. Wiki editors meanwhile indulge atheist nobodies with extensive biography entries.
Aside from Klinghoffer's usual histrionic bluster about silencing people who disagree with “Darwinism,” (Ken Ham, Henry Morris, John Morris, Stephen Myer, Michael Behe and, yes, even Klinghoffer, himself, have Wikipedia pages) the timing is very suspicious.  Additionally, if you thought he was well-known enough to have a Wikipedia page, why is he suddenly not so?  His page needs to be restored. This just makes Wikipedia look bad and smacks of censorship.

Sunday, November 19, 2017

Neandertal to Modern Transition Full of Fits and Spurts

New evidence suggests that Neandertals survived longer on the Iberian peninsula than elsewhere in Europe.  The redating of the Zafarraya Neandertal from the late 20k's to between 38 and 40 ky saw a revision of theories about Neandertal extinction. Now more evidence has been unearthed suggesting that this window is more secure.   From The Statesman:
Neanderthals may have survived at least 3,000 years longer than thought in what is now Spain – much after the species had died out everywhere else, a study has found.

The findings suggest that the process of modern human populations absorbing Neanderthal populations through interbreeding was not a regular, gradual wave-of-advance but a “stop-and-go, punctuated, geographically uneven history.”

Over more than ten years of fieldwork, researchers excavated three new sites in southern Spain, where they discovered evidence of distinctly Neanderthal materials dating until 37,000 years ago.

“Technology from the Middle Paleolithic in Europe is exclusively associated with the Neanderthals,” said Joao Zilhao, from the University of Barcelona in Spain.

“In three new excavation sites, we found Neanderthal artefacts dated to thousands of years later than anywhere else in Western Europe,” said Zilhao, lead author of the study published in the journal Heliyon.
It seems pretty clear now that the model of rapid replacement of Neandertals does not hold. This kind of evidence, along with sites such as Lagar Velho, suggest that the transition, at least in this region was long-term, with much hybridization.  We still do not know exactly how long Neandertals persisted in this region.  It makes perfect sense that they would have been the last ones to undergo the transition (however that happened) because the earliest Aurignacian sites, associated with modern humans, occur in far eastern Europe as the wave of moderns came through during the Würm I/Würm II interglacial.

The question that I have is why didn't the earliest modern humans, represented by the Jebel Irhoud remains, come through the Strait of Gibraltar?  North of that, all you find are archaic, all the way down to the Zafarraya remains.  I wonder why this is.

Monday, November 13, 2017

And, Apparently, The Stolen Bone is Only One Problem...

The journal Nature is reporting on a scandal of sizable proportions involving a site of early human occupation in Europe.  Ewen Callaway reports:
Serious concerns have surfaced about three research papers claiming evidence for one of the earliest human occupations of Europe.

In an extraordinary letter posted to the bioRxiv.org preprint server on 31 October1, archaeologists allege that the papers, published in 2013, 2016 and 2017, included material of questionable provenance, and that results reported in the 2016 paper were based on at least one stolen bone. Editors at the journals concerned are publishing expressions of concern about the papers.
The bioRxiv paper is available from the site and, since it is a preprint server, is accessible to anyone wishing to read the story. Here is the bombshell from the paper:
A series of recent papers on the Early Pleistocene palaeontological site of Untermassfeld (Germany) makes claims that are of great interest for studies of earliest Europe and are at odds with the described pattern: the papers suggest that Untermassfeld has yielded stone tools and humanly modified faunal remains, evidence for a one million years old hominin presence in European continental mid-latitudes, and additional evidence that hominins were well-established in Europe already around that time period. Here we evaluate these claims and demonstrate that these studies are severely flawed in terms of data on provenance of the materials studied and in the interpretation of faunal remains and lithics as testifying to a hominin presence at the site. In actual fact any reference to the Untermassfeld site as an archaeological one is unwarranted.
The site is said to have been occupied beginning around a million years ago, which was an astounding claim when it was made.  Critical, however, is that, despite the wealth of archaeological, taphonomic, faunal and floral evidence from the site, there have never been any hominin remains found. 

The article is lengthy but is a fascinating account of a palaeontological mystery and sleuthing.  If the accusations are true, it is blow for the study of early human European occupation and puts a stain on the whole proceedings. 

Thursday, November 09, 2017

Ken Ham Comes to Alberta

Young earth creationism is ubiquitous in home school curricula here in the United States.  Ken Ham is trying to make that the case in Canada, as well.  There has been pushback. Bill Kaufmann of the Calgary Herald writes:
Australian-born Ken Ham, a leading Christian fundamentalist proponent of creationism over evolution, is scheduled as a keynote speaker at the Alberta Home Education Association (AHEA) convention in Red Deer next April.

Ham spearheaded the building of a Noah’s Ark-centred creationist museum in Kentucky, and the educational books he’s authored includes Dinosaurs of Eden: Did Adam and Eve live with dinosaurs?

“Those who believe that only the uneducated reject evolution perhaps do not realize that evolution, far from fact, does not even qualify as a theory,” states an entry on his Answers in Genesis website.

“Evolution is a belief system about the past.”

It also offers a line of textbooks in areas of biology, geology and “creation apologetics.”
This is total nonsense. I would quote Todd Wood at this point, but he is probably tired of me quoting him. Suffice it to say, evolution is one of the most well-tested theories on the planet.  If you choose not to “believe” it, that is fine but to say that it is not a theory is just ignorant and foolish.  The more Ken Ham writes, the less I think he knows about how science works.   And now the pushback:
But Alberta Liberal Leader David Khan said while home schoolers have every right to invite speakers like Ham, it raises questions about what those children are being taught as science.

“None of that belongs in science curriculum, which should be mandatory for everyone regardless of whether they’re funded by Alberta Education or not,” said Khan.

“Having a bunch of kids lacking in basic science education is a problem for society writ large.”

He questioned whether Education Minister David Eggen is doing enough to ensure real science is being taught outside conventional classrooms.

While the AHEA doesn’t receive provincial funding, they’re expected to teach fact-based science, said Eggen’s spokeswoman Lindsay Harvey.

“All students, no matter what format of education they receive, are expected to learn from the current Alberta curriculum,” said Harvey.
I am generally not in favor of government oversight in home schooling. When that happens, you tend to get an agenda that seems to be tolerant of everything except “conservative” values.  Having said that, I wonder about all of these kids who wind up going to secular universities and having their faith blown apart by grounded, empirical science.  You can't mandate to homeschoolers what they should and should not teach unless you force a specific curriculum on them but stories like this shine a spotlight on home schooling that might be detrimental in the long run.

I wonder if Ken Ham is even aware of the damage that he is causing.  As Joel Edmund Anderson put it in his book The Heresy of Ham:
I believe that the paranoia, divisiveness, and frustration that the young earth creationist movement fosters wherever it goes should serve as an indication that there is something fundamentally wrong with it. This is not simply a case of Christians having a difference of opinion on a certain topic.  This is a case of a movement willing to declare war on everyone, Christian and non-Christian alike, who does not capitulate to what they have unilaterally declared to be true.
I couldn't agree more.

Thursday, October 19, 2017

Book Purchase: Adam's Quest

I hate it when books come out that escape my attention.  Such is the case with a book titled Adam's Quest, by Tim Stafford.  In it, Stafford has interviewed eleven scientists who have struggled with their understanding of how their faith fits in with their pursuit of science.  In a sense, this is like the book Four Views on the Historical Adam, in that it surveys Christians from different perspectives.  He has interviewed young earth creationists, supporters of intelligent design and evolutionary creationists.

As readers of this blog will note, I have been extremely critical of young earth creationists and intelligent design supporters, not so much for their beliefs (which I also find issue with, though) but for their ham-handed and often deceptive way in which they treat the scientific evidence for an ancient earth and evolution.  At least Todd Wood, one of the assembled scientists, has also had issue with this and, from what little I have read of Kurt Wise, he has as well.

Patheos has a short introduction to the book, which focuses on the first group, the young earth creationists, and some of their consternation at the way that science is examined.  There is a passage with a particularly damning quote from Kurt Wise about this:
After that, Wise lost interest in creationist apologetics, especially as he began to realize that many of the creationist evidences from his reading were wrong. “At first I thought it was ignorance.” As he learned more though, he became convinced that the mistakes in creationist literature were willful. … Wise concluded that for many creationists the end justifies the means. For them, “it doesn’t matter if what you say is true. It matters if it brings people to the right conclusion.” (p. 15-16)
This is, perhaps, why I find people like Ken Ham and his organization, Answers in Genesis so contemptible. They pretend to address the scientific concerns in an honest way but misinterpret evidence, arrive at faulty conclusions and smear hard-working scientists as a matter of course.  As i just told my oldest child, I am not going to come right out say they are lying, but it sure looks like it. 

Perhaps one of the scariest parts of the book and one of the principle reasons that I picked it up are in the sample that is available from Amazon, in which the author recounts his upbringing, which is almost word-for-word what I experienced growing up.  He then recounts every Christian parents' nightmare: the falling away from the faith of one of his children, in part because of the strains of learning correct science and being told that he could not be part of his circle of church friends if he continued to accept an old earth. 

Right now my children are in a home school group that is heavily young earth creation-based and I know that several of the parents of their friends would be horrified if they knew that I was an evolutionary creationist.  I simply don't advertise it. One of them thinks of Ken Ham as a hero of the faith.  How would it be of value for me to confront her with the notion that I think he is a charlatan and a heretic? 

As of yet, my oldest child does not seem to be tracking in any scientific direction so I doubt that this will have a huge impact on his life.  The same does not seem to be true with my second child, who is enamored with botany.  She will hit evolutionary biology head-on in college and I will have to prepare her for that and how to hold onto her faith throughout.  That will be, perhaps the greatest challenge that faces me. 

I look forward to reading this book with interest and would encourage downloading the sample.

Thursday, October 12, 2017

Uh Oh

Answers in Genesis is expanding into Canada, according the its leader, Ken Ham.  Patheos reports the following:
Answers in Genesis, the Creationist ministry run by Ken Ham, is evolving. Ham says that an Answers in Genesis–Canada is scheduled to open in 2018, with an online store launching earlier. It’ll be run by Calvin Smith, an Ontario native who has spoken about Creationism at churches across the nation since 2001.
From the Answers in Genesis website:
According to a recent study, a mere 15% of Canadians have any kind of creationist belief. The church there desperately needs AiG resources to be equipped to stand on the authority of the Word of God and boldly preach the gospel. We’re excited to be part of encouraging and equipping our Canadian brothers and sisters through speaking events, resources, conferences, and more.

AiG produces the world’s leading creation-apologetics resources including books, DVDs, curricula, the Answers Bible Curriculum (used in over 10,000 churches), and one of the top Vacation Bible School (VBS) programs used by over 5,000 churches last year.
For those of us who view Ken Ham's efforts in this direction with great apprehension, this is not good news. As Joel Edmund Anderson and Ted Davis note, Ken Ham preaches heresy and revisionist history. The more I read of the AiG site, the more I am convinced this is true.It is worth quoting Anderson again, here:
The heresy of Ham that is actively “subverting, destabilizing, and destroying” the core of the Christian faith is the claim that a modern, scientific interpretation of Genesis 1-11 as literal history is fundamental prerequisite for the trustworthiness of the Gospel of Christ. It is the claim that if the universe is not 6,000 years old, if there was no historical Adam and Eve, and if there was no worldwide flood 4,000 years ago, then that would make God a liar, that would mean there is no such thing as sin, and that would mean Christ died for nothing. Such a message is heresy, and that message has subverted, destabilized, and destroyed the Christian faith of many people, has destroyed careers, and unfortunately, has taken root within a significant portion of Evangelical Christianity.
Amen.

Wednesday, October 11, 2017

Taboo on Incest May Go Back at Least 34K Years

ZME Science is reporting on a study done from the site of Sunghir, in Russia that preserves “complex social structures,” indicating that, even at 34,000 years ago, there were precautions against inbreeding. Why do we think this?
The Upper Paleolithic burial site contains the complete remains of an adult male, the symbolically incomplete remains of another male, as well as those of two younger individuals. All of these people lived at this site during the same time. Unusual for similar finds from this period, all the four males were buried together.

When a team of scientists at the Cambridge University and the University of Copenhagen analyzed the genomes of these individuals, they were surprised to find they were not closely related. At most, one of the adults was no more related to the boys than a great-great-grandfather.

The researchers speculate that artifacts found at this location, which includes pieces of jewelry, may have been used in ceremonies and rituals that celebrated the exchange of mates between groups. Perhaps such exchanges foreshadowed modern marriage ceremonies.

In addition to the evidence that modern humans formed close-knit communities more than 30,000 years ago, this evidence also indicates that they deliberately sought mates beyond their immediate family.
Humans changed from a promiscuity-based relational strategy to pair-bonding at some point in their evolutionary history, which resulted in more stability.  Read the whole thing. 

Tuesday, October 10, 2017

The Effect of Neandertal DNA on Modern Humans

After the 2013 sequencing of the Neandertal DNA, Janet Kelso, of the Max Planck Institute undertook a study to see what genes present in Neandertals still had an effect on modern humans.  The study employed the data from a genotyping project done by UK Biobank, which surveyed 500,000 people.  What did they find? 
Kelso and her team first narrowed the sample to include only the 112,338 individuals with white European ancestry (whose genomes contain Neanderthal DNA), and used these data to tease out which traits are influenced by Neanderthal genetic variants. The traits they identified included those that affect hair color, skin color, skin tanning and burning, sleeping patterns, mood, and tobacco use.

For example, being a self-described night owl and being prone to daytime napping were both traits positively influenced by Neanderthal variants, as were loneliness, low mood, and smoking. Genetic loci associated with having red hair were found to be devoid of Neanderthal variants, suggesting red-headed Neanderthals were either rare or non-existent. The new study also supports Capra and colleagues’ previous observations that Neanderthal variants are associated with sun-induced skin lesions, mood disorders, and smoking.

That traits such as skin color, sun-burning, and sleep patterns were identified by the analyses might be explained by the Neanderthals’ adaptations to life at more northern latitudes, suggests Capra. But for other traits, he notes, determining how the effects seen in present-day people might once have affected Neanderthals themselves “is one of our crucial challenges.” For example, he says, “of course, Neanderthals were not smoking.”
Maybe I am behind the times but I did not know there was a “trait” for tobacco use. I figured you either did that or you didn't. Like Robin Williams says in Dead Again: either be a smoker or don't be a smoker. Choose it and be it.

I suspect we will continue to find effects of the Neandertal genome, especially since our understanding of how much interbreeding there was continues to change.  It is also a testament to the stability of the human genome that, even after a separation of some several hundred thousand years, interbreeding was still possible.  

Friday, October 06, 2017

Creation Museum Having Positive Impact on Economy of Florence, KY

Cincinnati.com is running a story about the impact that the Creation Museum is having on the economy of a nearby town, Florence, Kentucky.  Chris Mayhew writes:
Comfort Suites opened 84 rooms off Houston Road at 5905 Merchant St., Florence, in July. A busload of tourists from Alabama visiting the Creation Museum and Ark Encounter filled 24 Comfort Suites rooms for three days Sept. 27-29.

Tourism for Newport on the Levee, Downtown Cincinnati and the Creation Museum bring regular visitors, owner Ravi Narsinghani said.

Comfort Suites was Narsinghani's second hotel in Florence he owns with his brother. The brothers will open a third Florence hotel soon.

"We have an upscale extended stay coming," he said.
It is good that the local economies are getting a needed boost from this, even if it is for the wrong reasons.

Thursday, October 05, 2017

NCSE Post Reflecting on Kitzmiller, Twelve Years Later, by Eugenie Scott

NCSE has a guest post by Eugenie Scott, in which she remembers some of the points about Kitzmiller that might not have been public at the time.  It is part one of two.  In the run-up to the Kitzmiller trial, the plaintiffs did not know who the judge would be:
Well, the case was assigned to John E. Jones III, a fiftyish Republican who had been appointed by George W. Bush to the federal bench a few years before. “Intelligent design” proponents were delighted! In their blogs, they were quick to point out that Jones was a mover and shaker in Pennsylvania GOP politics, was a self-described conservative Republican, and was a church-going Lutheran, who certainly would be likely to find the ID policy constitutional.

I must say, our lawyers, who pay attention to judges more than we science types do, were a little apprehensive. What was this guy going to do? He’d only been a federal judge for a couple of years, so there wasn’t much of a record to go on.

His being a person of faith wasn’t an automatic concern. It’s so easy to misconstrue the creationism/evolution controversy falsely as “science versus religion,” when really it is one particular religious perspective versus everyone else’s. People are sometimes surprised to learn that our best allies in support of teaching evolution are other Christians: Catholics and mainstream Protestants— such as Disciples of Christ [with which Transylvania University is affiliated]—don’t want children taught Monday through Friday in science class that God specially created the universe in its present form 6,000 years ago, and then have to straighten them out on Sunday—because their theology is that God created through evolution.
One of the things that came out of the trial was how much the defense lied about what their true motives were. Although her post does not mention these events, it is an interesting account.

Wednesday, October 04, 2017

Why Is Homo floresiensis Still Such a Mystery?

Cosmos Magazine has an article by Debbie Argue, biological anthropologist from Australian National University, about Homo floresiensis and why it has been a struggle to accurately and adequately place this hominin within the framework of human evolution.

 Here was the initial assessment:
Peter Brown and colleagues originally proposed two competing hypotheses about the origins of H. floresiensis. One is that the species is an early hominin similar to the earliest identified in the Homo genus. The fossils for these species are known only from Africa and are between one and two million years old. This implies that the ancestors of H. floresiensis could have got to Flores Island in the vicinity of a million years ago and survived there until at least 60,000 years ago.

Their alternative hypothesis was that H. floresiensis is a dwarfed descendant of Homo erectus, which is the only known non-sapiens hominin to once have existed in Indonesia. Its remains have been found on the island of Java. According to this view, the dwarfing of H. erectus was an evolutionary response to being isolated on an island with a limited food supply. Just as the Asian elephant evolved into the dwarfed Flores stegodon after becoming marooned on the island, H. erectus could have met a similar fate.
It was also proposed that this hominin might have expressed microcephaly.  This idea failed to explain other aspects of the skeleton, however, such as its diminutive height (around 3 feet), long arms and feet and primitive skull features. Here is an image of H. floresiensis compared to a modern human, who had been running around the landscape for at least 100k years while H. floresiensis was extant.



This all saw at least some resolution with the discovery and description of some remains  on another areas of the island Flores that were very similar to the H. floresiensis remains but dated to some 600 thousand years earlier than the remains in Liang Bu.  This lent more credence to the idea that H. floresiensis was, in fact, an offshoot of Homo erectus.

So, Argue, along with Colin Groves, Bill Jungers and Mike Lee, performed statistical tests (this story does not say which kind, a peculiar omission) on a number of different hominin species, comparing them to H. floresiensis.  What did they find?
We therefore hypothesise that H. floresiensis shared a common ancestor with H. habilis. We do not know who that ancestor was or when it lived, but it would have to be older than the oldest H. habilis specimen known, so older than 1.75 million years. The implication is that the H. floresiensis ancestor evolved before that time in Africa, dispersed from that continent, and arrived on Flores earlier than 700,000 years ago, judging by the age of the jaw and teeth found at Soa Basin. This represents a hitherto unknown movement of very early hominins out of Africa.
Presently, the earliest evidence for hominins outside of Africa come from Europe, the Near East and Asia, and date to between 1.5 and 1.8 million years ago. Argue's hypothesis would suggest that H. floresiensis appearance in east Asia represents a separate migration out of African sometime either before or after the wave that saw Homo erectus show up in Trinil and Sangiran, in Indonesia.

Questions still abound as to why this species never saw the evolutionary trajectory that other hominins went through in terms of cranial expansion, increase in height and changes in brachial and crural indices. On the other hand, if evolution proceeds through what we have termed systematics, then advanced traits will show up in related species and if the ancestors of H. floresiensis were cut off, they would just go on their merry way.  We know that such a pattern holds for H. naledi, in South Africa, which coexisted with archaic Homo sapiens, in some way, shape or form. 

The article ends on a very peculiar note, in which she suggests the remote possibility that H. floresiensis is still alive out there, somewhere:
Could the Hobbit still exist in the wild mountain forests of Flores? When H. floresiensis was announced, the media picked up on the local folklore that small human-like creatures roam the forests. Descriptions of sightings are well recorded and quite detailed. The similarity to H. floresiensis is intriguing. But most researchers would say ‘show me the bones!’
This reminds one of the stories involving the Yeti/Sasquatch/Abominable Snowman, which likely derive from the finding of the bones of the Miocene ape Gigantopithecus, which was close to ten feet tall, when standing.  Is H. floresiensis still out there?  Probably not, but I am sure that the cryptozoologists haven't given up hope. 

Tuesday, October 03, 2017

Genetic Model Identifies Paranthropus boisei as Vector For Transmission of Herpes Virus

CNN (usual caveats) reports on a study that identifies Paranthropus boisei as the likely transmission vector of genital HSV-1.  From the story:
Herpes has been around a long time, to say the least.
Ancient chimpanzees genetically passed oral herpes (herpes simplex 1, or HSV-1) to the earliest humans millions of years ago when our lineage split. And we almost missed out on catching that other scourge, genital herpes (HSV-2) -- almost. Unlike HSV-1, HSV-2 didn't make the leap to early humans on its own.
Unfortunately for modern humans, millions of years ago, an early human ancestor was in the right place at the right time to catch HSV-2. And it might not have happened if it weren't for that meddling hominin species Paranthropus boisei, according to a new study in the journal Virus Evolution.
Why Paranthropus boisei, you ask? After all, P. boisei was not even on the main line of human evolution, coexisting with all manner of early Homo species at the same time, who likely out-competed them into extinction.  From the article, which is highly technical:
Paranthropus boisei would have been well placed to act as an intermediate host for HSV2. It most likely contracted the infection through hunting or more likely scavenging infected ancestral-chimpanzee meat. Processing (with or without tools) and consumption of raw meat would act as a simple path for ChHV1 to have crossed into P.boisei via open cuts or sores. Tropical refugia during hot dry periods may have driven chimpanzees into higher concentrations in certain areas, driving them into contact and competition with P.boisei and H.habilis as the margins of tropical forest blended into more open savannah-like habitats (Julier et al. 2017). Violent confrontation or hunting/scavenging and butchery practices would have provided a viable path of transmission for HSV2. Homo habilis remains have been recovered from the same layers as stone tools and bones carrying evidence of butchery, supporting a possible transmission–through-hunting/scavenging hypothesis for the initial anc-chimp to H.habilis transmission (Clarke 2012). Paranthropus aethiopicus, P. boisei, and P. robustus are associated with the Oldowan stone tool complex (De Heinzelin et al. 1999), and P.boisei explicitly with butchery (Domínguez-Rodrigo et al. 2013) lending support to the hypothesis that bushmeat hunting/scavenging and butchery may have led to the initial transmission of HSV2 to the hominins.
The entire exercise is very mathematical and relies on somewhat limited evidence of P. boisei behavior. It is, nonetheless, intriguing since it posits considerable interaction between the various hominin groups. 

Here is a mugshot of one of the perpetrators, the Zinj skull from Olduvai Gorge, found in 1959. 


Saturday, September 30, 2017

Did Humans Become a Distinct Species 350, 000 Years Ago?

The hits just keep on coming.  On the heels of the discovery in Morocco, at Jebel Irhoud, of a skull with some modern characteristics dated to 315 thousand years ago, we now have a genetic study that proposes that our species emerged between 350 and 260 thousand years ago.  How did a genetic study reveal this?  Science News reports:
The trick was retrieving a complete version of the ancient boy’s DNA from his skeleton to compare with DNA from people today and from Stone Age Neandertals and Denisovans. Previously documented migrations of West African farmers to East Africa around 2,000 years ago, and then to southern Africa around 1,500 years ago, reshaped Africans’ genetics — and obscured ancient ancestry patterns — more than has been known, the researchers report online September 28 in Science.
The ancient boy’s DNA was not affected by those migrations. As a result, it provides the best benchmark so far for gauging when Homo sapiens originated in Africa, evolutionary geneticist Carina Schlebusch of Uppsala University in Sweden and her colleagues conclude.
In line with the new genetically derived age estimate for human origins, another team has proposed that approximately 300,000-year-old fossils found in northwestern Africa belonged to H. sapiens (SN: 7/8/17, p. 6). Some researchers suspect a skull from South Africa’s Florisbad site, dated to around 260,000 years ago, qualifies as H. sapiens. But investigators often place our species’ origins close to 200,000 years ago (SN: 2/26/05, p. 141). There is broad consensus that several fossils from that time represent H. sapiens.
What is important to understand is that we have the fossils from Herto and Omo that date to between 150 and 200 thousand but that does not mean that is the earliest time that our species may have actually showed up. The Jebel Irhoud material is only partly modern—in the face mostly—and we do not know how the genetics for this population would look. It is possible that, as some investigators are saying, the Jebel Irhoud material represents the earliest fossil representation of our clade and that over the next 100 thousand years, the modern form fully evolved.   

Q&A With Lee Berger on Human Evolution

The Sunday Times has an interview with Lee Berger about human evolution, in advance of his new book, co-written with John Hawks, Almost Human: The Astonishing Tale of Homo naledi and the Discovery That Changed Our Human Story. As was reported earlier, the original fossils were undated but appeared to be reflective of an early stage in the development of Homo. This idea was shattered when new dates were derived.  As I wrote at the time:
Homo naledi, however, was missing a date—until recently. Nearly everyone in the scientific community thought that the date of the Homo naledi fossils, when calculated, would fall within the same general time period as other primitive early Homo remains. We were wrong. The radiometric dates—recorded using several methods carried out at different laboratories—yielded almost identical ages of between 236 and 300 thousand years before the present (BP). This was an order of magnitude younger than we expected. To say we were surprised would be an understatement.
Interestingly, the interviewer asks no important questions about Homo naledi or the Dinaledi Star cave, itself.  Amid all of the sturm und drang of his tortuous relationships with Ron Clarke and Philip Tobias (✟ 2012), there is one interesting question about human evolution in general:
Throughout the final chapters of the book you often mention how much there still is to learn about Homo naledi and that it’s very likely that there are more early hominim species which are yet to be discovered. The skeletal material you recently came across in the Lesedi Chamber shares similarities with Homo naledi and adds to this statement. What can/does this new discovery tell us about human evolution in Africa?

I think the clear picture that has come from both the discovery of Australopithecus sediba and Homo naledi is that the story of human evolution is not a simple, linear, straightforward one but that ours is a complex history. Naledi and sediba show us that there is more to be found – it’s clear that we don’t really know their ancestral history and the few fossils of other species found across Africa don’t help us much with interpreting where they fit in our family tree – and that’s exciting. We currently are back in the Dinaledi and Lesedi Chambers and making new discoveries – particularly exciting is we seem to have strong evidence that Homo naledi did indeed come down the narrow chute the way our “underground astronauts” come – and that is wonderful and hard to explain – but it’s exciting!
This has been a contentious issue: whether or not the fossil remains were “placed” there or were brought in by scavengers. What is also not clear is if the book was published before the new dates became available, or not.  I will have to buy the book to find that out.  While the rest of the interview is a tad unsubstantive, it is interesting.

Friday, September 29, 2017

Five Peculiar Fossils

Colin Barras of The New Scientist has a very short, very peculiar article on five hominin fossils that have been used to define new species and addresses the validity of each in very cursory fashion.  The strength of the article is in the links that it provides.  About Sahelanthropos, he writes this:
Features at the skull’s rear suggest it sat atop a vertical spine like that of a human, hinting that S. tchadensis walked upright. To make sure, other fossils will be needed – particularly from the legs. Unconfirmed reports suggest that a thigh bone was found with the skull, but this has not yet been discussed in a scientific paper. With so little evidence to go on, some are sceptical that S. tchadensis can really yet be defined as a hominin rather than some other form of ape – yet.
These are the least of its problems, as it is likely a surface find. Aside from this, when Wolpoff and colleagues examined the cranial base, here is what they found:
The prominence of the nuchal muscles, so important in head balance and loading, and shoulder movements, is enhanced by the significant development of the tuberculum linearum. The point is not that the TM 266 cranial rear and posterior portion of the cranial base was unlike hominids because the region looks like apes, but that TM 266 had a posture that is not upright because the region reflects nuchal functions similar to those of apes.

The foramen magnum - orbit plane angle does not directly address posture or locomotion in these hominoid primates (contra Zollikofer et al., 2005). Without a key postcranial element such as a pelvis or femur, none of these data provide compelling evidence for upright posture or obligate bipedal locomotion, and the various details of the nuchal plane argue against it. This functional implication has a phylogenetic consequence—by itself it is sufficient to disprove the phylogenetic hypothesis that TM 266 was a hominid.
This isn't skepticism. This is the door slamming shut.  It can be a surface find and still be a Miocene ape. In my recent piece for BioLogos, it did not occur to me to include this fossil since there are so many problems with it.  At this point, in Africa, the earliest reasonable evidence we have for hominins is Orrorin tugenensis

Read the whole (short) thing.

Thursday, September 28, 2017

Neandertal Child Gives Clues to How They Developed

Gizmodo is running a story about the discovery and examination of a Neandertal child, from El Sidrón Cave, in Spain, who died under mysterious circumstances:
The first step was to determine the chronological age of death by performing a dental analysis. The specimen, dubbed El Sidrón J1, exhibited a mix of baby and adult teeth. Incremental markings on the teeth, which are counted like rings on a tree, showed that the boy died at 7.7 years of age. The skeletal remains exhibited no signs of trauma, no signs of sickness, or any other physical abnormalities. El Sidrón J1, aside from experiencing an untimely death, appears to have been a perfectly normal and healthy Neanderthal child.

The researchers then compared the skeleton’s biological stage of development with what would be expected in a modern human of the same age. To their surprise, they found few differences between the two human subspecies in terms of the pace of growth.

“The comparison...indicate(s) that there was no noticeable difference in the growth and maturation of this Neanderthal juvenile in comparison with modern human juveniles,” said study co-author Luis Rios, a Member of the Paleoanthropology Group at Museo Nacional de Ciencias Naturales, at a press conference held yesterday.
Research has generally shown that Neandertals developed a bit more quickly than modern humans but, in one critical area, this study did not back up that claim.
Perhaps more significantly, analysis of the Neanderthal skull shows that El Sidrón J1's brain was roughly 87.5 percent the size of an average adult Neanderthal at the time of death. The brains of modern humans, on the other hand, reach 95 percent the size of an adult at that age. Previous studies have suggested that the larger brains of Neanderthals underwent rapid growth during these formative years, yet this new research would seem to contradict such claims.
There is a bit of circularity going on here, though because the child is being aged based on dental development and, if for some reason, the dental development does not completely track with either the current estimates or there were some developmental insults, the age might be off.  This is speculation on my part, though.  In any event, it gives us more to understand the developmental biology and ontogeny of these very, very close relatives.  

Wednesday, September 20, 2017

Forbes: Ark Encounter Local Tax Scandal Not Very Scandalous

I bit back I reported on the sale, not once but twice, of the Ark Encounter for $10 that, to all appearances, looked like a tax dodge gone bad.  Now Peter J. Reilly, who has written extensively about the Kent Hovind case, argues that, no it really was not that scandalous.  About the back and forth sale, he writes:
That had me a little excited, but as it turns out there is no federal tax issue. If you look at the Forms 990 filed by Answers in Genesis and Crosswater Canyon, you will find that Crosswater and AIG are both 501(c)(3) organizations and that Ark Encounter LLC is wholly owned by Crosswater making it, absent a special election, a disregarded entity. Transactions between the owner of a disregarded entity and the the disregarded entity are, for federal tax purposes, you know, disregarded. Status as a disregarded entity might not a apply for various local tax purposes. I wrote about an Orthodox Jewish school in Lakewood NJ that got tripped up by that. Apparently a similar rule applies in Kentucky, but I'm not equipped to dig deep there at this point.
Reilly sees that the coverage in the news about the transfer was very one-sided (and I did rely on that for my posts), but that there really was an ethical issue. He continues:
Ark Encounter's complaint of unfair treatment by the media might have some merit. Linda Blackford's coverage appears to me to be pretty solid and balanced, but some of what has been in the blogosphere has not been. For example, consider Dan Arel's headline - Ken Ham Sells Ark Encounter Land To Himself For $10 To Avoid Paying Taxes. I don't see that as a fair characterization as to what happened. Hemant Mehta's treatment on Patheos, though quite critical, is fairer and gives full credit to the new sources. Derek Welch of World Religion News got it backward saying that Ark Encounter sold the property to its subsidiary. The transfer was actually upstream.

On the other hand, I'm not displeased to see how they were hoist on their own petard when they transferred the property to beat the city tax. Overall the whole thing strikes me more as clumsy than smacking of deep conspiracy. All in, I think it was a mistake for the Ark to try to be frugal when it comes to supporting local services. Apparently, they think $500,000 is enough, but anything the city got over and above that would be from higher attendance.
The whole thing certainly left a bad taste in the mouths of the people of the Town, including the mayor. It also struck many, if legal, unethical. For someone like Ham, who decries the downfall of civilization because of moral failure, this seems a tad hypocritical.

Tuesday, September 19, 2017