Anthropology.net

For many years, the use of fire has been central to the discussion of human evolution. When was fire first controlled, and when was it first actually made by man? These are questions that rise again and again, but with scant early proof. Recently in the online journal Fire Ecology, an environmental scientist discusses what could be the earliest regular source of fire for our earliest ancestors (or potential ancestors).

Maybe an unconventional source for speculation on human origins, Michael Medler is an associate professor of environmental science at Western Washington University.  His paper can be broken into two sections, one based on reasonable observations in his specialty, and the other of speculation outside of his field (which in all fairness, the author sort of points out himself).

For millions of years in the African Rift Valley, volcanic activity went through periods of relative stability. Early groups of hominins going back millions of years would have been had access to lava flows, and in turn the benefits of heat and fire. Could it have been here that the earliest hominins started to add fuel to keep a fire going, keeping close to it for protection or warmth?

Homo erectus, a species that likely moved out of Africa aided by fire.

Maybe– but as Medler points out it is impossible to tell archaeologically. It is difficult enough for experts to determine fire usage in later instances, let alone millions of years ago in Africa.  If the earliest fire-users were in close proximity to lava flows, it is possible that the evidence would never be found. If charred bones turn up, who is to say that they were not burned by a natural fire? For now, this type of theory will remain almost strictly without archaeological evidence based simply on the principle of poor preservation.

However, the author states that there can be strong circumstantial evidence in support of his claims. If times of volcanic activity coincide with the presence of hominin species, this could perhaps be considered suggestive. As one example, Medler notes a period consistent with the emergence of Homo erectus.  Before 1.8 million years ago, there was a time of volcanic activity that was stable for about 200,000 years. This period overlaps with both the appearance of Homo erectus and their dispersal out of Africa—where knowledge of fire would have been an important factor.

There were many parts of Medler’s paper that had me questioning its integrity, namely the section on the use of tools.  While the sections that had me shaking my head were under the subheading “speculations and just so stories” I do not think this excuses him from their inclusion. He writes– without citation—-about how hand axes would have been more useful in cutting fuel than meat.  Where he got this information, I’m not really positive.

While this article does not seem to have been done in a circle of paleoanthropologists, the core ideas should get you thinking. Looking at volcanoes as a potential source of fire is intriguing, mainly because of the consistency with which they are present historically. Perhaps the next paper will have an anthropologist as a co-author.

By Matthew Magnani

Medler, M.J. 2011. Speculations about the effects of fire and lava flows on human evolution. Fire Ecology 7(1): 13-23. doi: 10.4996/fireecology.0701013

Very rarely is an entire family group of hominins buried and fossilized at the same time. It is even rarer for paleoanthropologists to discover such an assemblage. Fortunately for science but unfortunately for the hominins, caves occasionally collapsed on entire social groups.

Map of El Sidrón

At a site known as El Sidrón in Spain, excavations have been ongoing since 2000. To date, 12 Neandertals have been discovered in a context that points to a single geological event, circa 49,000 years ago. A group of 12 Neandertals is consistent with previous estimates of around 10 individuals per group.  At least six adults, three adolescents and four younger individuals were buried at once, most likely during a storm. The cold conditions of the cave system and immediate burial of the remains not only preserved the bones well, but were also ideal for DNA.

The remains were sexed based on both morphology and DNA analysis. After sex was determined, anthropologists identified the different Neandertal lineages based on mitochondrial DNA. Several of the adults were found to be male, and the other three female. It was discovered that all three males belong to the same matrilineal group, while each respective female has a different haplotype. When compared to modern Europeans, the authors noted that there is significantly less genetic diversity within the mitochondrial genome.

These results strongly imply that Neandertals exhibited patrilocal mating behavior. Females were the ones who would have changed family groups, not males. This type of insight into an extinct species is unique, thanks to the quality of DNA preservation available at El Sidrón.

Another interesting point of discussion in the study relates to Neandertal interbirth interval. One of the females was linked by DNA to two of the younger individuals, approximately several years apart in age. If the anthropologists are correct about the relationship, this puts the interbirth interval for Homo neanderthalensis at a value similar to hunter-gatherer groups today. This data, if replicated with other Neandertal individuals, could eventually dispel differential reproduction as a potential cause for Neandertal disappearance.

Knowing about Neandertal group dynamics could provide crucial clues as to why they went extinct. Future analysis of the remains recovered at El Sidrón will no doubt give more insights into our closest extinct relatives, and perhaps even why Homo sapiens flourished and Neandertals declined.

By Matthew Magnani

Lalueza-Fox, C., et al. (2011). “Genetic evidence for patrilocal mating behavior among Neandertal groups.” PNAS . January 4, vol. 108 no. 1 250-253.

Do you believe in evolution?  Forty percent of Americans don’t (more on that later).  A student asked me this question on day one of the first introductory anthropology class I ever taught.  I believe that any difficult-to-answer question is a good one, and this one baffled me with its simplicity.

Short answer: yes, I believe in evolution…but why was a modern college student in the United States asking me this?  The student was intelligent, curious, and friendly.  If anyone was naive, it was me for not expecting the question.  He’d simply been shaped by our culture to see evolution as a divisive matter of public opinion – and he wanted to know where I stood on the issue.  It would have been easiest to take his question at face value, answer yes, and move on to discussing the details of human evolution.  But, like so many idealistic teachers, I grasped the “teachable moment” and ran with it (annoying the many students who already believed in evolution and wanted to get into the good stuff):

• Science is an empirical method that (at least ideally) is not based on belief.  All scientific conclusions are tentative.  Scientific knowledge is evidence-based, ever-growing, and self-correcting since new or contrary evidence can be discovered at any time.  When asked what evidence would convince him that evolution was false, biologist J.B.S. Haldane remarked “Fossil rabbits in the Precambrian.”  Like all scientifically-testable ideas, evolution is falsifiable.  If rabbit fossils are found in Precambrian layers of rock (millions of years too early), I’ll be happy to explore alternative theories!
• There is also a major difference between the general and scientific uses of the word theory.  In everyday usage, theory means a guess or speculation.  In science, a hypothesis does not rise to the level of a theory without overwhelming evidence and explanatory power.  Anti-evolutionists dismiss evolution as “just a theory,” but scientifically-speaking, this is a gracious compliment.  Charles Darwin’s theory of evolution by natural selection has survived 150 years of rigorous challenges in every field from geology to genetics.
• Evolution may be politically, culturally, and emotionally controversial.  In the 19th Century, Darwin’s “dangerous idea” caused spiritual crises for many.  However, in the 21st Century, biological evolution is not scientifically controversial.  It’s an understatement to say that the evidence for evolution is overwhelming.
• Finally, scientific inquiry has revealed other phenomena that I “believe” in.  I believe in a round earth, though my senses tell me it’s flat.  I believe that the earth orbits the sun, not the other way around.  I believe in sexual reproduction, not the stork theory of baby origins.  I believe in particles like quarks, though I can’t see them directly.  And I do believe in evolution.

That’s a pretty long preamble, and one that most of my students had heard in middle school or high school biology classes.  Still, I thought “Do you believe in evolution?” deserved a thoughtful answer.  These days, I might answer “Yes.  Please read Jerry Coyne‘s Why Evolution is True” to save time.  After that, we were able to move into the actual evidence for evolution, all the cool hominid skulls, etc.

Assuming that Precambrian rabbits, or comparable out-of-place fossils, aren’t found anytime soon, the reality of evolution has been scientifically proven beyond a reasonable doubt.  So, it’s no longer necessary for anthropologists to summarize the scientific method before discussing human evolution, right?  Unfortunately, in the United States, evolution is still presented as if it was a political issue and, in some cases, it does enter the political arena (e.g., school board decisions).  Informed people can have differences of opinion over political issues.  In fact, one thing that ties Americans together is the core belief that political issues should be decided democratically.  But evolution is a scientific theory, subject to empirical evidence, not public opinion…and that may be a good thing.

Gallup poll results from December 17, 2010 show that 40% of Americans believe that “God created human beings pretty much in their present form at one time within the last 10,000 years or so.”  Make no mistake, the last 10,000 years have been a fascinating part of the human story – but they’re not the whole story!  Poll results like these make me feel both discouraged and reflective.  How is this possible in a developed country with educational opportunities like ours?  What can I do to better explain the human past (ALL of it)?  There is some truth to the argument that more and better education would help.  The same Gallup poll divides anti-evolution respondents by education level:

Gallup Poll on Evolution vs. Education

So education helps, but education alone cannot overcome the cultural/religious impediments that prevent more widespread understanding of biological evolution in the U.S.  Undoubtedly, many of the survey respondents took biology or anthropology as part of their education and still hold the belief that humans are new and separate from all other forms of animal life.  One hopeful sign is that 40% is the lowest percentage of “creationists” in Gallup’s history of asking this question – down from a high of 47% in 1993 and 1999.  There will probably always be a percentage of the population that is beyond the reach of evidence, especially with an emotionally-charged subject like evolution (after all, no one is freaking out about teaching gravity in public schools).

For cultural and historical reasons too numerous to go into here, Americans are not yet ready to embrace Darwin’s grand view of life – a view that has become so much grander and more elegant over the last 150 years.  It might take another 150 years for the culture to catch up with the science.  Those of us who love the science of humanity will keep doing our part to share the evidence for evolution and its role in shaping our species.

Do you believe in evolution?

Researchers from Stony Brook University Medical Center in New York confirmed that the Hobbits, or Homo floresiensis, are indeed a separate “human” species instead of a population of diseases Homo sapiens. The 7th Human Evolution Symposium, Hobbits in the Haystack: Homo floresiensis and Human Evolution was held this year at Stony Brook.

According to the press release, researchers William Jungers and Karen Baab used statistical analysis on the skeletal remains of LB1 (nicknamed Flo) to determine that Homo floresiensis are indeed a distinct species. A few characteristics of LB1 that makes her and her kind a separate species than modern humans.

• LB1′s cranial capacity is about 400cc, about the same size as a chimpanzee.
• The skull and jawbone of LB1 is more primitive looking than any normal modern humans.
• The thigh bone and shin bone of LB1are much shorter compared to modern humans including Central African pygmies, South African KhoeSan (formerly known as ‘bushmen”) and “negrito” pygmies from the Andaman Islands and the Philippines. Jungers and Baab believe that these are primitive retentions as opposed to island dwarfing.
• Using a regression equation developed by Jungers, LB1 was about 3 feet, 6 inches (106cm) tall, far smaller than modern human pygmies whose adults grow to less than 4 feet, 11 inches (150cm) tall.

Read more about the Hobbits at The geometry of hobbits: Homo floresiensis and human evolution (Free Wiley Interscience PDF).

Originally posted on The Prancing Papio.

The controversies over the hobbits or Homo floresiensis just refuse to end. It seems that the hobbits might not be a Homo after all. I guess they found the index and ring fingers of the hobbits (Sorry, inside joke. Read this post if you want).

Anyway, Peter Brown from the University of New England who first described Homo floresiensis said that he is considering of stripping the hobbits from the genus Homo. Brown and his colleague, Tomoko Maeda, said that the Homo floresiensis lineage possibly left Africa before the evolution of the genus Homo. Their paper had been accepted and will be published in an upcoming special Homo floresiensis edition of the Journal of Human Evolution.

I can’t wait for the paper to come out. In the meantime, you can read this article from The Australian.

Originally posted on The Prancing Papio.

Speaking of the Johansons and fossils …

Earlier this year, I’ve blogged about the 2009 Human Evolution Leakey Symposium at Stony Brook that I went to. For more about that blog post, click here.

The symposium, entitled “Hobbit in the Haystack: Homo floresiensis and Human Evolution” can now be streamed live through the Stony Brook website. The website also includes previous Human Evolution Leakey symposia. Click here to watch.

Thanks to Afarensis: Anthropology, Evolution and Science for the heads up!

Originally posted on The Prancing Papio

Language is a product of culture. Or is it? Which came first — language or culture? That’s like asking if the chicken or the egg came first. But cultural behavior has been documented in animals who do not have language systems, like gorillas who have intricate systems of processing plants. Richard Byrne summarized this behavior,

“Gorillas do not make tools in the wild… but several of their food-processing skills consist of highly structured, multi-stage sequences of bimanual action, hierarchically organized and flexibly adjusted to plants of highly specific local distribution and these abilities are near-ubiquitous among the local population. In terms of intricate complexity, gorilla plant-processing actually exceeds anything yet described in chimpanzees, unless tool-use per se is taken to be intrinsically more complex than non-tool-use. Gorilla, like Pan and Pongo, apparently sometimes relies for its survival on elaborate, deft and intricate feeding skills that are highly unlikely ever to be discovered by a solitary individual.”

This example is just one of many. It documents that culture can be created, persist and change without language. It does so through mimicking and augmentation. So it is generally assumed that culture came first, and language emerged as a system of formalized symbols, sounds, gestures used a means of communicating culture.

Why am I mentioning this at all? Well, we’ve seen, read and reviewed a couple of recent studies investigating cultural evolution and patterns in linguistic diversity. Most notably is the paper by Atkinson et al., where Simon and team showed that language evolves in bursts. Additionally, Deborah Rogers and Paul Ehrlich showed that cultural things have functional and symbolic elements, the former of which is under naturally selective pressures.

Despite these advances, there are some who still think that culture and everything related with culture is nothing but noise. I don’t know where they get this idea from. Even John Herschel and Charles Darwin understood that extant ‘languages descended from a common ancestor,’ and, ‘the formation of different languages and of distinct species, and the proofs that both have been developed through a gradual process, are curiously parallel.’ This observation was made before the publication of The Voyage of the Beagle and without a doubt helped lay the framework for the theory of evolution. The irony is that these vocal objections come from someone who specializes in studying material culture.

Anyways, I digress. John Whitfield, a science writer and blogger behind El Gentraso, has published a feature in the latest issue of the open access journal PLoS Biology where he summarizes “… the Curious Parallel of Language and Species Evolution.” As anthropologists, we should appreciate the remarkable tangents between the dynamics of linguistic change and biological evolution. Because of these similarities, it is possible to use tools and frameworks used in studying biological evolution to study how language changes… even how cultures evolve. Furthermore, it is very possible that we may soon see a synthesis of theories, one that folds in both both biological and cultural evolution.

Whitfield summarizes research by Simon Kirby, which I didn’t know about but find fascinating.

“Kirby has asked subjects to learn a nonsense language and then teach it to new subjects, and so on. He found that the randomness quickly became regularized, as people unconsciously shaped words into something easier to remember and use, and devised rules to come up with words for things they hadn’t seen. Such a process may be at work in the spontaneous emergence over the past few decades of two sign languages—Nicaraguan Sign Language and Al-Sayyid Bedouin Sign Language. Each of these has moved rapidly from a system of gestures to a fully fledged language with conventions for grammar and sentence structure. Kirby plans to use them as a test bed for his ideas about how structure in language can rapidly emerge.”

In the piece, Whitfield also got to ask Mark Pagel‘s what his thoughts are with synthesizing ‘the two’. Pagel is an evolutionary biologist. He was one of the coauthors of the paper with Simon Greenhill and Atkinson. He’s also published an earlier paper with Atkinson titled, “Frequency of word-use predicts rates of lexical evolution throughout Indo-European history.” Pagel responded saying,

“Languages are extraordinarily like genomes. We think there could be very general laws of lexical evolution to rival those of genetic evolution.”

Alex Mesoudi agrees. He told Whitfield,

“If there’s a model system for cultural evolution, then probably the people working on language have got it, because there’s so much data… Cultural change and biological change share the same fundamental properties of variation, selection and inheritance.”

William Croft is a bit more cautious but also understands that,

“these are two different instantiations of a general theory of evolutionary change. These are early days, but such a theory will give us insights that you can’t get just by looking at one domain.”

So what do you think — is it possible to synthesize the two? Or do they exist as two inherently different entities that change under different conditions?

Oh, you may also be interested in this related video discussion between Paul Ehrlich and Carl Zimmer — where Ehrlich advocates that cultural evolution needs its own theoretical framework aside from evolutionary biology. Strange proposition, especially because he used a natural selection framework in his latest PNAS paper.

Pagel, M., Atkinson, Q.D., Meade, A. (2007). Frequency of word-use predicts rates of lexical evolution throughout Indo-European history. Nature, 449(7163), 717-720. DOI: 10.1038/nature06176

Byrne, R.W. (2007). Culture in great apes: using intricate complexity in feeding skills to trace the evolutionary origin of human technical prowess. Philosophical Transactions of the Royal Society B: Biological Sciences, 362(1480), 577-585. DOI: 10.1098/rstb.2006.1996

Whitfield, J. (2008). Across the Curious Parallel of Language and Species Evolution. PLoS Biology, 6(7), e186. DOI: 10.1371/journal.pbio.0060186

Cultural evolution has been a pretty active and heated topic in the anthropology blogosphere, especially between Martin, afarensis, and I. Afarensis continued the discussion today, returning to this topic but on the projectile point scope.

In some sort of weird coincidence, the professional press has also chimed in — not explicitly on projectile points, but on cultural evolution. I tip my hat to Simon Greenhill, who found these these two relevant pieces and posted about them in his blog HENRY. The first, a review on “Evolution in Archaeology,” by Stephen Shennan­ has been published in the Annual Review of Anthropology journal. The second, this column in Seed Magazine by Paul Ehrlich — who recently published a research paper in PNAS on cultural evolution, as well as a back and forth series of letters with a criticizer of his work.

Shennan is well versed in cultural evolution. He is one of the co-authors of a text titled, “The Evolution of Cultural Diversity: A Phylogenetic Approach.” In his Annual Review of Anthropology review, Shennan describes the history of how people have approached cultural evolution. He brings up the differences in the two analytical camps, ‘one centered on cultural transmission and dual inheritance theory and the other on human behavioral ecology,’ and how they have effected answering evolutionary questions with archaeological data. In summary, he effectively advocates that we need to find and agree on new, consistent ways of using archaeological data to answer evolutionary questions.

Ehrlich’s message starts out on a similar tone. In his second paragraph, he writes how we do not really “understand how cultures evolve.” He pays particular attention to the ambiguous nature of culture — something that “composed of overlapping phenomena from languages, religions, institutions, and socially transmitted power relationships to the information embodied in artifacts ranging from potsherds to jumbo jets,” and how it hard to extract patterns from all these varying sources that seem so bogged down with noise.

But Ehrlich ultimately reconsiles in that culture can be analyzed broadly, and under the same theoretical constraints that we analyze genetic evolution — so long as we through out that cultural evolution is progressive. His piece transitions into a summary of his recent research, but I still recommend you read it because it does a much better job with translating the science than I can, since he was one of the authors behind the piece.

Both are effective pieces in synthesizing evolutionary theory with the concept of culture. It is very problematic for one to discuss both or refute that culture doesn’t evolve without a strong understanding of the theoretical basis of evolution, selection, and change.

Ari Löytynoja and Nick Goldman have developed a new method that detects and distinguishes insertions and deletions in genomes. Their work was published in the most recent issue of Science. While Löytynoja and Goldman didn’t explicitly write how their new algorithim, described in, “Phylogeny-Aware Gap Placement Prevents Errors in Sequence Alignment and Evolutionary Analysis,” impacts our understanding of human evolution and how we compare primate genomes, it is an important to understand what they’ve accomplished.

Up until now, people compared and contrasted sequencing similarities of multiple genomes using a tool that does a multiple sequence alignment. A commonly used tool is called CLUSTALW. And I’ve used it a lot. CLUSTAL will take long strings of DNA sequences and align them based upon their shared similarities. When a sequence is the same between the samples, they are matched… When sequences aren’t the same, they are marked as gaps. Every consecutive pairwise match between two or more sequences are given a score, and every gap is given a penalty.

Many different alignments are computed and the one with the best score is presented. Phylogenetic trees are drawn off of these sequence alignments. The problem is that this method disregards judging if a length difference between two sequences is a deletion in one or an insertion in the other sequence. This ultimately and systematically creates errors in comparisons of genetic sequences of different species… check it out for yourself, the image below shows the traditional alignment on the left and the new alignment algorithim on the right:

This is where Löytynoja and Goldman’s new algorithm, PRANK, a phylogeny aware algorithm, shines. The phylogeny-aware approach,

“flags the gaps made in previous alignments and, using evolutionary information from related sequences to indicate whether each gap has been created by an insertion or a deletion, permits their “reuse” for inserted characters without further penalty in the next stage of the progressive alignment. In addition, information from closely related sequences can be used to infer sites as “permanent” insertions that cannot be matched in subsequent alignments, so that distinct insertion events are correctly kept separate even when they occur at exactly the same position. If related sequences indicate that a gap is caused by a deletion, flags are removed and no further free gaps at that position are permitted, and the effect is correctly targeted on insertions only.”

Löytynoja explains,

“Say we are comparing the DNA of human and chimp and can’t tell if a deletion or an insertion happened. To solve this our tool automatically invokes information about the corresponding sequences in closely related species, such as gorilla or macaque. If they show the same gap as the chimp, this suggests an insertion in humans.”

In their sample set, they compared sequences of primates to primates, primates to rodents, and primates to all mammals, they were able to identify that insertions are far more common in primate evolution than deletions. Furthermore, the frequency of deletions have been exaggerated because of the inability of previous tools to effectively detect them… which makes me wonder if primates, relatively recent in evolutionary times has been under a relaxed, diversifying level of positively selection? Like some sort of explosion of adaptive radiation of the taxon… I haven’t completely thought this thru, just something that popped into my mind while writing this.

Loytynoja, A., Goldman, N. (2008). Phylogeny-Aware Gap Placement Prevents Errors in Sequence Alignment and Evolutionary Analysis. Science, 320(5883), 1632-1635. DOI: 10.1126/science.1158395

I’ve been meaning to blog about the really awesome news that Afarensis first broke on the blogosphere for a couple days now. The news he shared is of an upcoming Journal of Archaeological Science paper authored by R. Lee Lyman, Todd VanPool and Michael O’Brien, all of the University of Missouri Anthropology Department, evaluating the selection and optimization of projectile points.

I’ve tracked down the paper. It is currently more or less an accepted draft and titled, “Variation in North American dart points and arrow points when one, or both, are present.” Yesterday, Afarensis supplemented his news coverage with a little questionnaire he asked one of the authors, Dr. Lyman specifically. Dr. Lyman answered the questions and provided a little bit more information than the initial press release provided.

To give you a quick digest, Lyman, VanPool, and O’Brien analyzed over 1,000 projectile points from three archaeological sites; Verkamp Shelter in Missouri, Gatecliff Shelter in Nevada, and Mummy Cave in Wyoming. The collection of points span at least 3,200 years of time and all include the date the bow and arrow were introduced and used in these regions. Upon the introduction of the bow and arrow about 1,7000 years ago, Lyman et al. were able to see that people experimented to find the optimum point. They did that by synthesizing cladistic analysis, which O’Brien specializes in and concluded that there was

“initial burst[s] of variation in projectile points… and that prehistoric [people] experimentally sought arrow points that worked effectively. Following that initial burst, less-effective projectile models were discarded, causing archaeologists to see a reduction in variation.”

So these people tested many different projectile points. The ones that were functionally more effective were the designs that were selected and further optimized, kinda like punctuated equilibrium. Diversity was lost once the best points were identified. Sounds right in line with other models of cultural selection, such as the 60,000 year old tool kits Sibudu Cave that also showed those people experimented with tool design to accomplish a variety of tasks.

I believe I have a good understanding of the archaeological record and I think it is really safe to say that humans have always experimented with tools, selecting ones that were functionally superior to tools that weren’t. That is optimization, to make the best or most effective use of a tool.

You can see for yourself, some of the first examples of stone tools are classified as Oldowan type. They first appear in the record about 2.5 million years ago, also known as the Lower Paleolithic. They were very simple. About 1.5 million years ago, a new type, Achulean tools appear. They are much more refined and optimized for special tasks compared to Oldowan tools.

Following Achulean stone tools, the Levallois, Aurignacian, and Magdalenian techniques succeeded into the Upper Paleolithic becoming more specialized with time than its predecessor. I’ve posted examples of each typology in chronological order, from Oldowan tools to specialized Solutrean blades, for you to see how tools have been refined over time. Optimization of tools did not end with the Neolitihic revolution. In fact, tools have been constantly revised to fit the new tasks that came about as humans began to adopt sedentary lifestyles over nomadic ones.

So I’m really disappointed, shocked even, to read from Martin, an archaeologist… someone who is supposed to specialize in studying material culture, commenting on this topic and writing that cultural selection is irrational, arbitrary, and does not optimize. He cites face painting as an example about how cultural selection is full of ‘null mutations.’ Based off of his choice of comparisons, I don’t think he understands the difference between functional and symbolic traits in cultural memes. And this is alarming.

A very recent paper, authored by two biologists from Stanford, evaluated the differences in the rates of change between functional and symbolic traits in Oceanic canoe design. I recommended Martin read up on it, if he hasn’t already, because in the paper Ehrlich and Rogers clearly distinguish the difference between symbolic and functional traits… Something that Martin did not with his example. Symbolic ones, as Martin pointed out, are highly variable — but functional traits, ones that affect the survivability of the user are rapidly revised and selected.

Adding to his foolish comparison, Martin also stated that once upon a time pre-scientific humans existed. While trained scientists haven’t been around until relatively recently, people have always been experimenters. The inquisitive nature of humans has been a fundamental aspect of our evolution, both biological and cultural. Furthering this idea, he writes that, ‘he is convinced that both people in the lo-tech past and people of the present are largely ignorant non-optimisers who mainly do things with no adaptive significance.’ Without ‘scientific,’ adaptive minded optimizing humans, we would not have had cave art, fire, agriculture and animal domestication… we’d be still eating tubers out of the ground.

I really hope people see beyond Martin’s comparison. Let me remind you that he’s comparing apples to oranges, literally. Symbolic things, like face painting, trinkets on a fishing pole, adornment on a canoe, offer little functionality. Projectile points are functional elements, that directly correlate to a successful hunt and survivability. The are selected in different operant realms. Also, this is not the first time example of Martin’s asininity… in the past he’s spun this mindless mantra and wondered if genetic evidence is relevant in the peopling of the Americas.

LYMAN, R., VANPOOL, T., OBRIEN, M. (2008). Variation in north american dart points and arrow points when one, or both, are present. Journal of Archaeological Science DOI: 10.1016/j.jas.2008.05.008