Thursday, March 28, 2013

Richard Wrangham, Catching Fire: How Cooking Made Us Human (2009)

Edward O. Wilson's research on eusociality led him to identify the nest as a common attribute among the eusocial species.  Although not proven, Wilson surmises that a gene has been suppressed among the eusocial species that silences the brain's program for dispersal from the nest, leading to the sustained survival of the eusocial community.  (September 12, 2012 post)  Humans are included among the eusocial species, but humans disperse; they do not build and congregate in nests, but they do build and maintain social communities comprised of multiple generations and humans are organized into groups by altruistic division of labor, which are characteristics of eusocial species.  As a surrogate for the nest, Wilson suggests that the campfire served a nest-like function in the development of the genus homo, which strongly suggests that  mastery of fire was critical to humans eusociality. 

As I read Wilson's The Social Conquest of Earth (see September 12, 2012 post), I was reminded of a book on the bookshelf that addressed this topic, Richard Wrangham's (see  July 1, 2010 postCatching Fire: How Cooking Made Us Human.  Wrangham believes that mastery of fire was critical to human evolution, but even more important, mastery of fire enabled early humans to cook their food on a regular basis. According to Wrangham, cooked food is even more significant than mastery of fire for human evolution.  Armed with data and concrete examples Wrangham demonstrates that eating cooked food is linked to two evolutionary changes in the human body:  (1) comparatively smaller, more efficient digestive systems (particularly the stomach and the small intestine) that require less energy to digest food and absorb nutrients than our predecessors, and (2) larger brains.  Large brains require significant amounts of energy, and that energy is available to the brain only if it is not needed for other activities essential for survival such as eating and digesting.  Compared to apes and chimpanzees (and presumably extinct australopithecines and habilines), humans spend a fraction of their daily life eating and digesting food.  Apes and chimps spend hours eating plant food or fruit every day.  The relative weight of the human gut is roughly only 60% of the relative weight of the gut of apes and chimpanzees.

The controversial question is when did the first species among the genus homo begin cooking food?  For certain the benefits of and development of a preference for cooked food was accidentally discovered.  Wrangham believes that human cooking begins with homo erectus.  There is anthropological evidence cited by Wrangham that cutting meat with primitive stone tools began as early as 2.6 million years ago.  Roughly 300,000 years later, a new species, referred to by some as homo habilis, which still had many australopithecine characteristics, emerged, and roughly another 500,000 years later the species referred to as homo erectus, emerged according the available fossil record and lived on the African continent for nearly 1.5 million years (until roughly 300,000 years ago).  While it is doubtful that homo erectus had language capacity or skills (see January 31, 2013 post discussing homo neanderthalensis), what we do know is that the cranial capacity of early specimens of homo erectus was 200cc greater than homo habilis and later specimens 400-500cc greater than homo habilis, representing an increase in brain size of approximately 33-75% over the habilines.  (See November 21, 2012 post).  That would be the largest incremental percentage increase from species to species within the genus homo. Homo erectus is recognized to be, in many respects, to be much closer to modern homo sapiens than homo habilis.  Combined with some evidence of the use of controlled fire at sites where homo erectus bones have been found, the control of fire and the significant increase in brain size (the energy for which is enabled by decreased energy used in eating and digesting food) lead Wrangham to identify homo erectus as the first human species to favor and consume cooked food on a regular basis.  Wrangham also speculates that homo erectus, unlike its predecessors, favored sleeping on the ground (instead of trees) and the control of fire would have been useful in providing light to see predators at night or keeping predators away.  The morphology of erectus is not as suitable for sleeping in trees as its predecessors.

Others (Aiello and Wheeler) have concluded that cooking food is the invention of homo heidelbergensis (the predecessor to homo neanderthalensis) a later species.  Aiello and Wheeler believed that brain size was steady among homo erectus until the emergence of heidelbergensis with its larger brain.  Wrangham finds the fossil record sufficient to support the view that brain size gradually grew among erectus and believes that the steady increase in size is attributable to improved cooking techniques, and that continued growth in brain size to heidelbergensis and ultimately to homo sapiens is likely similarly associated with improved cooking techniques, not cooking as a novel adaptation or spandrel. 

Wrangham's thesis is this:  "An important step in fire's becoming a central part of human lives was to maintain it at night.  Suppose some habilines carried a smoldering log by day to protect against predators, then left it at the base of a sleeping tree when they climbed to make a nest at night.  It would not have been such a big step to give it extra fuel so the log will still be burning the next day --perhaps after seeing this happen first by accident.  From there it would have been a smaller step to sitting near the fire to keep it burning, and thereby take advantage of its protection, light, and warmth.  Once they kept fire alive at night, a group of habilines in a particular place occasionally dropped food morsels by accident, at them after they had been heated, and learned that they tasted better.  Repeating their habit, this group would have swiftly evolved into the first Homo erectus.  The newly delicious cooked diet led to their evolving smaller guts, bigger brains, bigger bodies, and reduced body hair; more running; more hunting; longer lives; calmer temperatures; and a new emphasis on bonding between females and males.  The softness of their cooked plant foods selected for smaller teeth, the protection fire provided at night enabled them to sleep on the ground and lose their climbing ability, and females likely began cooking for males, whose time was increasingly free to search for more meat and honey."  So despite the relative dearth of evidence of fire dating back to the time of homo erectus, Wrangham believes that the dramatic shift in brain size and tooth size is significant evidence that Homo erectus started the first outdoor cooking kitchen. 

Division of labor by sex.  E.O. Wilson also includes altruistic division of labor among the attributes of eusociality (September 12, 2012 post).  Wrangham has a discussion that dovetails with Wilson on this point.  First, cooked food liberated males to spend more time hunting for meat in a way that chimps and apes cannot because they spend so much time chewing their food.  Fire enabled men to confine their eating time to the hours around dusk and even after dark.  Hunting enabled the male to contribute food to his family (including an extended family group), but this effort was ultimately dependent upon a reliable, predictable economic exchange between women and men.  Women became foragers and this provided a reliable source of food energy in the event that the men of the group returned with no meat.  Women also became primarily responsible for cooking.

Wrangham argues that while relying on cooked food created opportunities for cooperation, more importantly it exposed female cooks to exploitation because cooking takes time and lone cooks could not easily guard their wares from thieves.  This problem was solved, Wrangham believes, by pair-bonds among males and females:  a "husband" ensured that the woman's gathered foods were not taken by others and from this evolved "a simple marriage system." The male provided the female (and their children) with meat.  Consistent with Boehm's observations (see November 21, 2012 post), Wrangham observes (based on anthropological evaluation of modern hunter-gatherers) that meat is actually shared among a larger group that includes not only the male's "wife" and children, but also an extended family (and possibly a stranger).  The female's distribution of gathered food is largely shared just with her "husband" and their children.  In the gathering of food, there may very well be cooperation among women, but the sharing of the gathered food is limited to the immediate family.  Presumably sharing meat among a larger group evolved because direct reciprocity is essential to the hunting and killing of the large animal, bringing the meat back to the campfire and slaughtering it. 

Thursday, March 14, 2013

Edward Humes, Monkey Girl: Evolution, Education, Religion and the Battle for America's Soul (2008)

Deception and religion have been joined at the hip for a very long time, perhaps as long as religion has existed in human culture given that religion has its origins in believing what we can never see or know.  Monkey Girl is Edward Humes' account of the Dover Township, Pennsylvania school board's effort to introduce the subject of intelligent design into the high school science curriculum and the litigation that ensued when parents stepped forward and asked a court to enjoin the school board's effort on the ground that it offended the First Amendment of the U.S. Constitution.  What the 6-week trial in a United States District Court exposed was concerted deceit on the part of groups opposed to the teaching of natural selection  and what Charles Darwin called "descent with modification" in public school curriculum because it offended the biblical stories that lead them to the belief that god (an intelligent designer) created each of the species separately and the view of some that these acts of creation began no more than 10,000 years ago.  Comparable acts of deceit in the commercial world would be called mislabeling or misbranding or fraud.  In court, it is called perjury.

The drive to engage in the acts of deceit documented by Humes begins with the United States Supreme Court's decision in 1987 that the teaching of creationism offended the First Amendment's Establishment Clause and could not be taught in public schools.  If creationism could not be mandated as a subject of instruction in United States public schools these groups began to think about branding creationism as something else, something that sounded like it belonged in the science classroom --- intelligent design.  Their legal strategy, for example, compelled them to abandon the words "god" and "creator" and relabel god an "intelligent designer."  Their legal strategy also compelled them to create a controversy when, at least in the scientific community, no substantial controversy existed:  the existence of an intelligent designer would be deemed a serious scientific question and one that demanded that schools "teach the controversy."  The lingo of creationism and its relationship to the book of Genesis had to be purged if science students had any chance of being taught an alternate explanation of the creation of species alongside natural selection and descent with modification in the classroom.  This was no easy task.  To biblical literalists, it was confusing and did not sit well with the hard core biblical believers who wanted to drive natural selection and "Darwinism" from science class because, in their view, it was atheistic.  But for the advocates of intelligence design, their difficulties extended beyond the religious motivations of the Dover school board.  Not only were the intelligent design advocates ultimately unable to succeed in concealing the religious motivations of the school board, it turns out there was a long and unambiguous record demonstrating that intelligent design had its intellectual seed in creationism.  The very book that the intelligent design advocates wanted the high school students of Dover to have in their classroom, Of Pandas and People, had been drafted prior to the Supreme Court's 1987 decision in Edwards v. Aguillard, and the drafts had used the word creationism.  By the time of publication, after the Supreme Court rendered its decision in Edwards, the word creationism had been deleted everywhere and replaced with the term intelligent design. 

At the heart of the lawsuit, known as Kitzmiller v. Town of Dover, was this question:  was intelligent design science or religion?  For the plaintiffs, intelligent design was on trial; for the defendants and their supporters, traditional science was on trial.  After a six week trial in which the court heard from scientists on both side of the question, the court found that intelligent design was not science; it was religion. 

The scheme to inject intelligent design --- as opposed to creationism --- into the science curriculum begins with a paper developed by a University of California law professor, Phillip Johnson, that came to be known as the "wedge strategy," because it envisioned hammering a "wedge" into the tree of science by criticizing evolutionary theory --- putting science on the defensive and exploiting religious sentiment that was not only skeptical of evolutionary theory, but was essentially ignorant about natural selection and the body of scientific literature that had substantiated Darwin's natural selection model.  The wedge document was developed by Johnson in collaboration with the Discovery Institute, and essentially outlines not a scientific research program, but a public relations strategy to persuade people that a scientific controversy existed and that the public needed to be made aware of the controversy.  The wedge document was never intended to be made public, and it was forthright and honest in expressing the goals behind the wedge strategy, leaving no doubt about its theistic underpinning: 
  • "to defeat scientific materialism and its destructive moral, cultural and political legacies.
  • "to replace materialistic explanations with the theistic understanding that nature and human beings were created by God."
  • to initially see, within five years, "intelligent design theory as an accepted alternative in the sciences and scientific research being done from the perspective of design theory" and within 20 years to see intelligent design theory as the dominant perspective in science" and to see "design theory permeate our religious, cultural, moral and political life." 
  • "Design theory promises to reverse the stifling dominance of the materialist worldview, and to replace it with a science consonant with Christian and theistic convictions."
During the Kitzmiller trial, however, the lawyers for the defendants, like Peter denying Jesus, wanted nothing to do with the wedge document.  They argued that it was a "mere fundraising proposal" of little significance.  The lawyers for the defendants desperately tried to prevent the plaintiffs' witness, Barbara Forrest, who testified not only about the revisions to the Pandas and People book but also about the wedge document, from testifying at all. 

A central part of the Discovery Institute's strategy was to change the ground rules of science so that it not only included the natural, material world, but also the supernatural ethereal world.  The problem with this project is that it is nothing less than the merger of science and religion.  According to the testimony of the plaintiff's expert at the Kitzmiller trial, "Science is the systematic attempt to provide natural explanations for natural phenomena."  The exclusion of the supernatural from science was unavoidable.  A scientific theory is testable, and is capable of being proven false.  The supernatural is not testable.  Judge Jones concluded, "Intelligent design is predicated on supernatural causation. . . . Creationism, intelligent design, and other claims of supernatural intervention in the origin of life or of species are not science because they are not testable by the methods of science.  These claims subordinate observed data to statements based on authority, revelation, or religious belief."

Numerous posts in this blog raise issues that are relevant to the Kitzmiller case:

Teleology v teleonomy.  (June 12, 2011, May 24, 2010  and March 24, 2010 post).

The human propensity for self-deception and deception.  (February 4, 2012, August 28, 2011, and May 22, 2011 and May 12, 2010 post)

Anthropomorphism, anthropotheism,  and anthropodenial.  (March 20, 2012, June 12, 2011 and June 17, 2010 post).

Dualism and materialism.  ( December 17, 2012, February 27, 2011 and September 27, 2009 post)

At its core, the intelligent design movement, as exposed in the wedge document, is about as un-American as any group can be.  The long-run goal is for design theory to permeate not only religious, cultural, and moral life, but also "political life."  This is so contrary to the First Amendment of the United States Constitution, one would think the design movement's adherents were really living in modern Iran or some other theocracy.  Yet what Monkey Girl reveals is that the intelligent design movement has so little respect for the First Amendment, because they believe the government has abandoned religion by recognizing the freedom of atheists, skeptics (agnostics), and pantheists who imagine a universe governed by natural laws (see January 31, 2013 post) and they believe the government has abandoned its moorings as a "Christian nation."  In contrast, Humes closes out Monkey Girl with a quotation from the 1796 Treaty of Tripoli, signed by founding father President John Adams:

"As the Government of the United States of America is not, in any sense, founded on the Christian religion, as it has in itself no character of enmity against the religion, or tranquility of Mussulmen; and, as the said States never entered into any war, or act of hostility, against any Mahometan nation, it is declared by the Parties, that no pretext arising from religious opinions, shall ever produce an interruption of the harmony existing between the two countries."  (Emphasis added).

Nor should one forget the Jefferson Bible, in which founding father Thomas Jefferson, excised the text pertaining to miracles and other supernatural events. 

I have a proposal that will surely bring the intelligent design movement and creationists running back for the protection of the First Amendment.  Congress should pass a law that requires every religious school class to teach the following every Saturday or Sunday:  "The Book of Genesis is a story.  It was written and later edited by men who could not explain their origins or the origins of the physical universe including other life on earth and life and other material beyond the earth.  It's a wonderful story and it even has meaning, but it is just a story.  Our origins really did not happen they way, Adam and Eve were not real people, and the other stories that purport to be written history of the Hebrews are merely stories as well.  There may be some little historical basis in some of these stories, but they have been gilded, edited, redacted, and revised to fit a collective memory long after the events described in Genesis purportedly took place.  And by the way, children, did you not see that Genesis mentions nothing about the dinosaurs and other animals that lived on earth millions of years ago, whose bones we find in the ground today.  Children, do you not wonder why Genesis does not mention dinosaurs and other animals who no longer exist?  The answer is simple.  The men who wrote the stories in Genesis did not know about these animals.  They were not as knowledgeable as you are today."  Once the law is passed, I am sure there will be a lawsuit.  Maybe the ACLU will be the plaintiff.

In Edwards v. Aguillard, Associate Justice of the Supreme Court Antonin Scalia dissented from the majority's decision that struck down Louisiana's statute that called for the "balanced treatment" of "creation science" and "evolution science" in Louisiana schools.  The 7 member majority of the Court authored by Justice Brennan and the concurring opinions of Justice Powell and Justice White found plenty of evidence that creation science lacked a secular purpose and was religiously inspired.  "This is not a hard case," wrote Justice White.  The case came before the Supreme Court based on the trial court's grant of a motion for summary judgment, which meant the trial court found enough undisputed evidence presented by the plaintiff's challenging the Louisiana statute to warrant granting a judgment without a full evidentiary trial.  Justice Scalia professed to take no position on the merits of "creation science," but he felt that Louisiana deserved a full evidentiary trial before an appellate court such as the US Supreme Court decided whether or not there was a valid secular purpose.  One would think, and hope, that Justice Scalia, informed by the full evidentiary record in Kitzmiller, would have recognized as Justice White did in Edwards that "this is not a hard case" had the Kitzmiller case made its way to the Supreme Court for judicial review, and that he would recognize that intelligent design deserved the same fate that creation science received in Edwards