CHAPTER 2 – ANTS | ANTERNETS | MANURE
Information about harvester ants comes from conversations with Deborah Gordon, her two books, and her numerous journal articles. Gordon’s books are Ant Encounters: Interaction Networks and Colony Behavior (Princeton: Princeton University Press, 2010) and the earlier Ants at Work: How an Insect Society is Organized (New York: W.W. Norton, 2000). Her journal articles can be found on her Stanford University web page. For a general overview, Dr. Gordon gave an impassioned speech during the 2003 TED Conference entitled “The Emergent Genius of Ant Colonies”. Note the HREF tag “Deborah Gordon digs ants”, which I thought was interesting enough that I repeated it in the first line of chapter one. TED, which stands for “Technology, Entertainment, Design,” is a global set of conferences created to disseminate ideas.
For a more general overview of ants, also see EdwardO. Wilson and Bert Hölldobler’s The Ants (Cambridge, Mass.: Harvard University Press, 1990); and Edward O. Wilson’s The Insect Societies (Cambridge, Mass.: Harvard University Press, 1971) and The Social Conquest of Earth (New York: Liveright, 2012).
There are many general interest books on the brain that are worth reading, although none that I know of that compare the brain to ants. For a general overview, see How the Mind Works by Steven Pinker (New York: W. W. Norton, 1997), Consciousness Explained by Dan Dennett (Boston: Little, Brown, 1991), Principles of Psychology by William James (Cambridge, Mass.: Harvard University Press, 1983), and In Search of Memory: The Emergence of a New Science of Mind by Eric Kandel (New York: W. W. Norton, 2006).
The Deborah Gordon quote comparing ant communication to Twitter messages comes from an article by Molly Vorwerck, “Deciphering Ant Communication,” The Stanford Daily, November 16, 2010.
The phenomenon of ants circling until they die is discussed in Frédéric Delsuc’s article, “Army Ants Trapped by Their Evolutionary History,” PLoS Biology 1, no. 2 (2003): e37.
The quote in which Deborah Gordon discusses hassling ant colonies comes from her TED talk, mentioned above.
Dan Dennett compared the internet to an alien invasion when he was interviewed by Dr. David G. Stork and Michael O Connell, for the documentary 2001: Hal’s Legacy. The interview is entitled “Evolution Intelligence: Daniel C. Dennett Interview.”
Internet statistics change as rapidly as they are published, but two of the best sources are Internet World Stats, which tracks the world’s internet usage and Netcraft, which does a monthly survey to estimate the number of websites on the internet. The most recent survey can be found here.
Wikipedia estimates that in 2007, YouTube alone consumed as much bandwidth as the entire internet did in 2000. YouTube provides its own statistics.
The Washington Post reported Netflix statistics on May 17, 2011: “Video Viewing on Netflix Accounts for up to 30 Percent of Online Traffic” by Cecilia Kang.
ZDNet announced in 2011 that “Facebook Is Bigger than the Whole Internet Was in 2004.”
To discover the similarities between ant communication and the internet’s Transmission Control Protocol (TCP), Deborah Gordon worked with Stanford computer scientist Balaji Prabhakar. The resulting paper, “The Regulation of Ant Colony Foraging Activity without Spatial Information,” was published in the August 23, 2012 issue of PLoS Computational Biology.
For more information on how the brain uses a process similar to TCP to limit the flow of information, see René Marois, and Jason Ivanoff’s journal article “Capacity Limits of Information Processing in the Brain,” Trends in Cognitive Sciences 9, no. 6 (2005): 296-305 and also an article by The Physics arXiv Blog, “New Measure of Human Brain Processing Speed,” MIT Technology Review, August 25, 2009.
Neuroscience is truly an evolving field and because it is so new, information tends to be sparse or becomes out of date very quickly. I discuss the problem of finding accurate brain statistics further in chapter nine. Nonetheless, I have tried to use the most commonly cited statistics regarding the brain. For the number of neurons and connections in the human brain, I went with an adult mature brain having around 100 billion neurons and 100 trillion connections. It should be noted that recent research suggests the number of neurons may be around 86 billion, although this number is largely up for debate so I opted for the most conventional number throughout the book. For information on the latest research into the 86 billion theory, see Frederico A.C.Azevedo, , Ludmila R.B. Carvalho, Lea T. Grinberg, José Marcelo Farfel, Renata E.L. Ferretti, Renata E.P. Leite, Wilson Jacob Filho, Roberto Lent, and Suzana Herculano-Houzel, “Equal Numbers of Neuronal and Nonneuronal Cells Make the Human Brain an Isometrically Scaled-up Primate Brain,” Journal of Comparative Neurology 513, no. 5 (2009): 532–541. The number of neural connections is also contested, but the general consensus is 100 trillion connections. See, for example, Robert W. Williams and Karl Herrup, “The Control of Neuron Number,” Annual Review of Neuroscience 11 (1988): 423–53; Gordon M. Shepherd, ed., The Synaptic Organization of the Brain (Oxford University Press, USA: 2003); Narayanan Kasthuri and Jeff W. Lichtman, “Neurocartography,” Neuropsychopharmacology 35, no. 1 (2010): 342-343; and Carl Zimmer, “100 Trillion Connections,” Scientific American 304, no. 1 (2010): 58-63.
The number of neural connections in the brains of infants and children are even harder to determine accurately, but the consensus is that they peak at roughly 1,000 trillion neural connections. See, for example, Dennis Garlick, “Understanding the Nature of the General Factor of Intelligence: The Role of Individual Differences in Neural Plasticity as an Explanatory Mechanism,” Psychological Review 109, no. 1 (2002):116-136. The research shows that the number of neuronal connections decreases significantly from its childhood number, but again, sources vary as to how many connections are lost. For more information about the brains of infants and children, read The Scientist in the Crib: What Early Learning Tells Us About the Mind (New York: HarperCollins, 1999) by Alison Gopnik, Andrew N. Meltzoff, and Patricia K. Kuhl.
Recent data has shown that neurons, not just neural connections, also decrease during adolescence. Lawrence K. Low and Hwai-Jong Cheng of the Center for Neuroscience at the University of California-Davis published their finding in 2006 that 50 percent of post-mitotic neurons do not survive until adulthood: “Axon Pruning: An Essential Step Underlying the Developmental Plasticity of Neuronal Connections,” Philosophical Transactions of the Royal Society of London Series B, Biological Sciences 361 (2006): 1531–1544. Also see J.A. Markam, J.R. Morris, and J.M. Juraska’s “Neuron Number Decreases in the Rat Ventral, but Not Dorsal, Medial Prefrontal Cortex between Adolescence and Adulthood,” Neuroscience, 144: 961-968. Markam’s research was also covered by ScienceDaily on March 19, 2007 in their article “The Brain Loses Neurons During Adolescence,” written from materials provided by the University of Illinois at Urbana-Champaign. For more detail on the numbers of neurons and connections, see my book Wired for Thought: How the Brain Is Shaping the Future of the Internet (Boston: Harvard Business Press, 2009).
The amazing rate of neuronal growth of fetuses can be found in Ross A. Thompson’s journal article “Development in the First Years of Life,” published in The Future of Children 11, no. 1 (2001): 21–33.
The extent to which ants and other eusocial insects collapse or prune their colonies is not well understood. It is clear that for each species, there is a breakpoint at which the colony stops growing, but no one has investigated the extent to which it overshoots first or the reasons why it does. It should also be noted, as Dr. Gordon has pointed out to me, that in these cases it is not the environment that the animals are overshooting—that would, of course, lead to a total collapse, similar to what happened with the St. Matthew Island reindeer. Instead, they are likely overshooting some other natural equilibrium point, a topic we return to later in the book.
The data about the number of devices connected to the internet comes from Cisco’s 2011 white paper entitled “The Internet of Things: How the Next Evolution of the Internet is Changing Everything.” For an impressive visual representation of the internet of things, including cows and farmers, see Cisco’s infographic.
The reindeer data used to create image 1.3 is from David R. Klein’s article “The Introduction, Increase, and Crash of Reindeer on St. Matthew Island,” Journal of Wildlife Management 32, no. 2 (1968): 350–367.
The MySpace data used to create image 1.3 is from the article “The Rise and Inglorious Fall of MySpace,” by Felix Gillette which appeared in Bloomberg BusinessWeek on June 22, 2011. Additional MySpace data was gathered from MySpace’s Wikipedia article. The rise in number of links on the homepage was calculated by using the Wayback Machine at web.archive.org to look at older versions of MySpace.
Whether or not the ant or the colony is an organism has been discussed often in science and literature. Edward O. Wilson and Bert Hölldobler have a nice history of this debate in The Ants.
The story about the nineteenth-century horse problem in New York City has been told numerous times, most recently in Superfreakonomics: Global Cooling, Patriotic Prostitutes, and Why Suicide Bombers Should Buy Life Insurance by Steven D. Levitt and Stephen J. Dubner (New York: William Morrow, 2009). I relied principally on details from the Living City Archive at Columbia University, the Sirolli Institute, as well as a November 16, 2009, New Yorker article entitled “HOSED: Is There a Quick Fix for the Climate?” Additional information on the history of New York City comes from a November 15, 1880, New York Times article entitled “The City’s Sanitary Work.”
Consumption estimates for the internet come from the aforementioned Cisco white paper “The Internet of Things.”