Pachyderm Problems for Zoo Elephants

In the December 12 issue of the journal Science Ros Clubb of the Royal Society for the Protection of Animals and colleagues, including well known elephant researcher Cynthia Moss, report that captive elephants do not live as long as their free-living counterparts, or even as long as working elephants in Burmese timber camps.

Collecting data from over 4,500 elephants from European Zoos, wild populations in Amboseli National Park in Kenya and working elephants in Burmese logging camps, the authors found a significant correlation between captivity and longevity. Females from a well studied population of African Savannah Elephants (Loxodonta africana) in Amboseli National Park in Kenya exhibited a median life span of 56.0 years (these data excluded mortality from humans). African Savannah Elephants in zoos have a median life span of only 16.9 years. As of 2005 when the study ended female African Savannah Elephants in captivity experienced a mortality risk 2.8 times higher than the natural mortality of wild female elephants in Amboseli. Captive-born female African Savannah Elephants die earlier in zoos than in the wild but infant and juvenile mortality was similar between wild and captive elephants.

For Asian Elephants (Elephas maximus) the effect of zoo captivity on mortality was also significant. Captive female Asian Elephants in the study exhibited a median life span of 18.9 years while working Asian Elephants in a Burmese timber operation had a median life span of 41.7 years. While mortality risk in African Savannah Elephants went down over time, suggesting improved captive management, there was no significant reduction in mortality for Asian Elephants. Also, being born in a zoo versus born in the wild had a significant effect on surviorship in Asian Elephants. Ironically, wild-caught Asian Elephants did better in captivity than their captive-born counterparts.

Elephants live in tightly knit social groups of females and juveniles with very long-term associations among individuals. Wild female elephants rarely move between groups, but, zoos regularly transfer individuals among institutions. Female Asian Elephants are moved around among European Zoos approximately once every 7-years. Transfers have an effect on the health of captive elephants. This study found that inter-zoo transfers significantly reduced survivorship in Asian Elephants.

Georgia Mason, a co-author on this study and zoologist at the University of Guelph in Ontario, Canada, discussed the results on the December 12 Science Magazine podcast. According to Mason the situation for American zoo elephants is no better than their European counterparts. 15% of zoo-born elephants in Europe die in their first year while in the USA 40% of zoo-born elephants die before the age of one.

Small group size, frequent inter-zoo transfers, and comparatively tiny enclosures for an animal that has orders magnitude greater home range area in the wild are all likely contributors to the problem of reduced survivorship in zoo elephants. However, solutions to this problem are not straightforward. Large sums of money have been spent in European and US zoos to build larger enclosures for captive elephants but the study by Clubb and colleagues found little evidence that such improvements have resulted in increased survivorship in captive elephants. Some increases in survivorship for African Savannah Elephants have occurred but not nearly enough to bring their surviorship on par with wild counterparts and the study found that despite increased spending and larger enclosures there was no increase in survivorship for Asian Elephants. Mason in the Science Podcast interview pointed out that recent expenditures of approximately 23 million US dollars spent on improving enclosures for the elephants at the Oklahoma City Zoo were greater than the entire annual budget for the Kenya Wildlife Service or the South African National Parks Authority. Perhaps the greatest concern is that captive elephant populations are not self sustaining and can not survive without introduction of individuals taken from the wild.

This study provides a compelling argument for an elevated discussion on not just captive elephants but the welfare of other large-ranging, social mammals as well. Hopefully this study will place a renewed emphasis on future research and novel approaches to captive husbandry of these magnificent mammals.

Clubb, R., Rowcliffe, M., Lee, P., Mar, K. U., Moss, C., Mason, G. J. (2008). Compromised Survivorship in Zoo Elephants Science, 322 (5908) DOI: 10.1126/science.1164298

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Interview with Judge John E. Jones III

The journal PLoS Genetics has published a wonderful interview with Judge John E. Jones III. A conservative federal judge in the US District Court for the Middle District of Pennsylvania, Judge Jones was recommended for his current position by PA senator Rick Santorum and appointed to the bench by President George W. Bush in 2002. Judge Jones ruled for the plaintiffs in Kitzmiller versus Dover Area School District striking down a school board policy exposing students to intelligent design creationism in the public classroom.

In the PLoS Genetics interview Judge Jones is asked about his own personal views on creationism and evolution. After saying that as a judge he can review a case independent of his personal views he adds,

"I am a person of faith. I'm certainly not an atheist or an agnostic and I see some divine force somewhere. That said, having had a pretty good education, a great liberal arts education at Dickinson College, I must say that I never had any substantial doubts about evolution generally. I had forgotten, admittedly, a lot of what I had learned about evolution back in college. Moreover, a lot had happened since the '70s, so my understanding was rudimentary. But I never had a crisis of confidence about evolution or a reason to doubt that it constituted a valid theory and good science."

Brown University biologist Ken Miller was an expert witness in the trail and recently gave a wonderful lecture on evolution and intelligent design as part of the Cincinnati Museum Center's Dury Science Lecture Series. Here's what Judge Jones had to say about Dr. Miller's testimony in the PLoS Genetics interview,

"I will always remember Ken Miller's testimony in the sense that he did A–Z evolution. And then got into intelligent design. And having laid the foundation with the description of evolution, got into why intelligent design doesn't work as science, to the point where it is predominantly a religious concept."

Contrast this with Judge Jones opinions of the expert witnesses for the defense, particularly Lehigh University professor Michael Behe,

"Another remarkable moment on the science side was Michael Behe, who was the lead witness for the defendants, and a very amiable fellow, as was Ken Miller, but unlike Miller, in my view, Professor Behe did not distinguish himself. He did not hold up well on cross-examination."

That a conservative self-proclaimed "person of faith" appointed to the bench by President Bush rules so desisively against the teaching of intelligent design creationism speaks volumes for the validity of the evolution position and the vacuity of intelligent design from a scientific and, in so much as the idea is applied to public education policy, legal stance.

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Yeast goes with the FLO

“Share and share alike”, so goes the old adage about equally distributing goods, even at one’s own expense. Darwin’s idea of natural selection explained evolutionary change by posing that traits spread in the population due to the benefits these traits confer on their bearers. Individuals with certain characteristics produce more offspring relative to those individuals with other characters and as a result the population as a whole takes on a different appearance. However, Darwin’s idea couldn’t explain those traits that provide benefits to others at the expense of their bearers. Sharing with others at one’s own expense is called altruism and in biology altruism remained a puzzle for over a century after Darwin.

Then come the 1960’s and William Hamilton. Hamilton said that a rare gene underlying some altruistic behavior could spread despite the cost to the bearer. But how? How could a gene that results in fewer offspring for its bearer spread in the population? Lucky for Hamilton he had an understanding of genetic inheritance that was not available to Darwin. If behavior is directed towards those individuals in the population who also harbor the same genes for altruism then the trait will spread in the population through the recipients of altruistic behavior. Rare genes for altruism would more likely spread if there were a readily observable marker of the same altruistic gene in others. Richard Dawkins popularized this idea in the 1970’s calling it the ‘green beard effect’. In a hypothetical example Dawkins imagined that genes for altruism would result in a marker, such as a green beard, along with the altruistic behavior. With this clear marker of the altruistic gene in others helpers could direct their behavior only towards those that shared the gene for altruism.

Amazingly there is good evidence for the ‘green beard effect’ in nature in several organisms, from slime molds and fire ants. Even more astonishing, there are examples where a single gene is responsible for ‘green beard’ altruism. Scott Smukalla, Marina Caldara, and Nathalie Pochet of Harvard University and their colleagues report in the latest issue of the journal Cell that they have found a ‘green beard’ gene in the budding or brewer’s yeast, Saccharomyces cerevisiae.Yeast is not only the critical component in the making alcoholic beverages but it is also a classic model system in the study of the eukaryotic cell. Yeasts are single celled organisms but wild strains of Saccharomyces cerevisiae in times of stress will aggregate into multicellular mats often called biofilms. These aggregates of cells can protect cells from antibiotics, heat and cold stress, ethanol, and other toxins. The coming together of single yeast cells into a multicellular group is called flocculation and the aggregations are known as flocs. Occurring in wild yeast in response to stress, flocculation allows the population to ride out tough times.

Typical of many organisms grown under the resource-rich and stress-free conditions of the laboratory, times are seldom that tough and many years of culture in the lab have lead to the loss of flocculation in laboratory strains. Comparing a wild, flocculent strain called EM93 with a laboratory strain, S288C, incapable of forming flocs, Smukalla and colleagues found that flocculation fell under the control of a single variable gene called FLO1. This was confirmed by activating the expression of FLO1 in normally non-flocculent S288C cells. Expression of FLO1 resulted in flocculation exactly like that observed in wild yeast. FLO1 expression creates cell membrane proteins that allow cells to recognize and adhere to other yeast cells expressing the FLO1 gene.

FLO1 in Saccharomyces cerevisiae acts like the ‘green beard’ gene predicted by Hamilton as it allows yeast cells to detect others also expressing FLO1 and form multicellular aggregates and thus provide group protection against environmental toxins. But, remember altruism by definition involves a cost to the altruist. Where is the cost? When grown under toxin free conditions and ideal temperatures yeast expressing the FLO1 gene suffer a 4-fold reduction in population growth relative to yeast cultures that do not express the FLO1 gene.

A mixed culture of FLO1 expressing and non-FLO1-expressing cells grown under conditions that lead to flocs results in flocs containing primarily FLO1 expressing cells and free cells that do not express the FLO1 gene. FLO1 is therefore a true ‘green beard’ gene as it promotes the altruistic, social trait (flocculation) and at the same time excludes participation of those cells not expressing the social trait. Requiring FLO1 for cell adhesion eliminates the spread of selfish cheaters, yeast cells that forego the cost of expressing FLO1 while times are good but also reap the benefits of flocs when times are tough.

Research on the evolution of social, altruistic traits like flocculation can shed light on one of the most important transitions in the history of life, the evolution of multicellular organisms from single celled organisms. Saccharomyces cerevisiae, social amoebae, slime molds and many social bacteria move between a single celled and a multicellular lifestyle. Like Saccharomyces cerevisiae, multicellular forms in other microorganisms are often in response to stressful environments. Very early in our own evolution the colonization of harsh environments by our single celled ancestors likely promoted the same altruistic behavior seen in many modern microorganisms today.

S SMUKALLA, M CALDARA, N POCHET, A BEAUVAIS, S GUADAGNINI, C YAN, M VINCES, A JANSEN, M PREVOST, J LATGE (2008). FLO1 Is a Variable Green Beard Gene that Drives Biofilm-like Cooperation in Budding Yeast Cell, 135 (4), 726-737 DOI: 10.1016/j.cell.2008.09.037

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Ken Miller speaks at Cincinnati Museum Center

This Thursday, December 4th at 7:30pm at Cincinnati Museum Center's Union Terminal Dr. Kenneth Miller of Brown University will speak in the museum's Dury Science Lecture Series. Dr. Miller is a cell biologist and author of life sciences textbooks and popular books on the conflicts between evolution and intelligent design creationism.

A vocal proponent of evolutionary biology in the public arena Dr. Miller has been featured on the PBS series Evolution and served as an expert witness in the recent Kitzmiller v. Dover Area School Board case in US District Court of Middle Pennsylvania. Dr. Miller's testimony played a critical role in the Judge John Jones' decision which declared that the Dover school board's policy to promote intelligent design (ID) theory in public school science courses was in violation of the US Constitution's Establishment Clause because, while presented as science, "ID cannot uncouple itself from its creationist, and thus religious, antecedents".

While proving to be highly effective at exposing the deep flaws within this latest version of scientific creationism, ID theory, Dr. Miller has provided a counterpoint to creationist/ID accusations that evolution promotes atheism by being very open about his own personal beliefs in the Christian faith. Miller's highly successful popular book Finding Darwin's God was not only an effective rebuttal against ID but also a personal testimonial of a Christian scientist's ability to reconcile faith with the scientific consensus on biological evolution. His latest book, Evolution and the Battle for America's Soul, dismantles ID arguments and emphasizes the explanatory power of evolutionary biology in making sense of life's diversity.

In a dwindling economy with environmental and energy crises looming larger and innumerable challenges for the US both domestic and abroad the ability to innovate is critical in moving America forward. The launch of the Sputnik satellite in 1957 by the Soviet Union was a wake-up call for the US and spawned an increased focus in science education and research in the 1960's. The rising prominence of China and India in science and engineering is today's Sputnik and Americans need to decide if they want to continue to be leaders and producers of science innovation and technology or followers and consumers of technology provided by other nations.

Far from an esoteric issue the debate between ID creationism and evolution cuts to the heart of science education in the US. On the one side is scientific innovation and adoption of evidence based inquiry and the other is an attempt to roll back two centuries of scientific progress and judge scientific evidence on the basis of narrowly-defined, preconceived socio-religious ideology. Attending Dr. Miller's lecture at the museum center will be an excellent introduction to these critical issues in American scientific literacy and demonstrate that, contrary to what creationists would have us believe, scientific progress need not come at the expense of our religious faith. I hope to see you there.

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