Three new books say animals have souls, go to heaven

July 11, 2010 • 8:47 am

The Long Beach Press-Telegram (or rather, Alfredo Garcia of the Religious News Service) reports on three new books that affirm the existence of souls in animals:

The fate of our four-legged friends – whether they have a soul, whether they’ll be in the afterlife – has occupied the minds of Christian thinkers ever since the days of St. Thomas Aquinas and St. Augustine.

Three recent books try to answer the question, and affirm a special relationship between humans and animals – one that does not end with death.

It’s this kind of “theology” that makes the faithful look ridiculous, especially when it’s couched like this:

Author Ptolemy Tompkins tracks the history of the relationship between humans and animals in the new book, “The Divine Life of Animals.” Prompted to write by the death of his pet rabbit, Angus, Tompkins looks to the ancient past for the best models of animal-human interaction.

“Pre-modern cultures … were apparently able to see animals as undying spirits dressed, for the moment, in mortal bodies,” he writes.

The idea is to recover that “new-yet-old vision” that “will allow us to see (animals) as the genuine soul-beings they are and always have been.”

There are two other screeds along these lines. One is The Friends We Keep, by Laura Hobgood-Oster, professor of religion at Southwestern University in Georgetown, Texas:

“There does not seem to be any indication (in Scripture) … that there is a special human exclusion (in heaven),” Hobgood-Oster said.

And, finally, I Will See You in Heaven by Friar Jack Winz:

Reluctance to the idea of animals in heaven persists in some Christian circles. Last year, Franciscan Friar Jack Wintz published the book, “Will I See My Dog in Heaven?” This year, he answered his own question with a new book, “I Will See You in Heaven.”

Taking inspiration from his order’s founder, St. Francis of Assisi, who’s also the patron saint of animals, Wintz presents biblical evidence for the inclusion of animals in heaven.

In the book of Genesis, he writes, both humans and animals live in peaceful harmony – “a wonderful and insightful glimpse of the paradise that is to come,” he writes.

“It makes sense to me, therefore, that the same loving creator who arranged for these animals … to enjoy happiness in the original Garden would not want to exclude them from the final paradise,” he writes.

More than anything, this genre of belief shows that religion is based on wish thinking rather than evidence.  How, exactly, does the soul enter the zygote when a sperm and an egg fuse? Does each gamete have half a soul?  And if our personality and all our memories are coded in our neurons, which decay after death, how can we be the same people, with all those memories, in heaven?  Do frogs have souls, too?  What about fruit flies?  Sunflowers?

But never mind.  Who wouldn’t want to see Fluffy again, disporting herself amongst the clouds and chasing celestial mice (who apparently never get caught)?  But the Bible says that humans alone—not cats, dogs, squirrels, skunks, copepods, and ferns—are made in the image of God.  And if theologians want to debate whether they’ll meet Happy Cat or Rex or Angus teh Bunneh (Fig. 1) in the afterlife, well, let them look stupid.  It all contributes to the palpable irrationality that will eventually bring down religion in America, as it already has in much of Europe.

Fig. 1.  Bunneh heaven (artist’s rendition).

Deceptive predatory cat imitates monkey calls

July 11, 2010 • 6:22 am

Many people see dogs as open, loving, and honest, and cats as duplicitous, cunning, and sly (Fig. 1).  This gross misconception will be reinforced by a paper in the new (but dated July 2009) issue of Neotropical Primates, which you can download for free. The authors, Fabiano de Olivera Calleia, Fabio Rohe, and Marcelo Gordo, show that a wild cat imitates the sounds of baby monkeys  to lure its prey within reach.

Fig. 1.  Popular view of cats vs. dogs.  From Cat versus Human by Yasmine Surovec

The cat is the margay (Leopardus wiedii), a small (two foot long), solitary inhabitant of Central and South American rain forests. It’s famous for its climbing abilities, spending much of its time up in the trees. Indian Wildlife describes the margay’s climbing skills:

One of the most remarkable characteristics of the margay is the exceptionally flexible ankle joint. It can supinate through 180° enabling the margay, unlike most cats, to run head first down a tree. This is quite evidently an important adaptation for a tree-dwelling animal. They can grasp branches equally well with their fore and hind paws, and are able to jump considerable distances. Margays have been observed to hang from branches with only one foot.

Margay babies are sometimes tamed by the locals. I once got to hold a (relatively) tame margay that belonged to a bar in Costa Rica; it let me pet it but then sank its teeth into my silver ring, leaving a sizeable dent.  Here’s a short video of this beautiful cat:

Calleia et al. report that margays appear to subsist on arboreal mammals (including monkeys), but up to now their methods of predation haven’t been described.  Interviewing inhabitants of the Amazon rainforests, the authors were told that several species of jungle cats attracted prey by imitating the prey’s vocalizations.  And, while studying wild pied tamarins (Saguinus bicolor), they actually saw this behavior: a margay imitating the cry of a baby tamarin. Here’s their description:

On October 12, 2005, at 9:13 am, a group of eight pied tamarins monitored by telemetry was feeding in a Moraceae (Ficus sp.). A large vine at 15 meters height connected the surrounding trees to the fig tree. At 9:18 am, a margay attracted the attention of a tamarin sentinel (Gordo et al., 2005) by producing calls similar to those emitted by pied tamarin pups. The adult male sentinel climbed up and down the tree to investigate the calls coming from behind the liana tangles. It assumed a surveillance position and, using specific calls, warned the group about the foreign calls. At 9:22 am we observed movements in the vine and keep hearing the call imitations. At 9:29 am three pied tamarin individuals were feeding on Ficus sp. while the tamarin sentinel was keeping surveillance. At 9:40 am, four pied tamarins climbed up and down the Moraceae in response to the repeated aggressive calls from the tamarin sentinel. At that moment, was observed a cat with small body but big feet, huge eyes and a long tail walking down the trunk of a tree (like a squirrel); it quickly jumped to a liana that was connected to the fig tree and moved toward where the tamarins were feeding, about 15 meters away. At this moment, the sentinel emitted a high scream as the predator approached the group; and the group fled immediately.

The only thing that’s lacking in this report is a recording of the cat, but of course they couldn’t make one because this was a fortuitious encounter.

This is, I think, the first description of a wild cat luring its prey by mimicking its calls. Although this particular attack was unsuccessful, you can see how imitating the calls of prey could help you get a meal.  If this behavior is real—and I suspect it is—we can speculate whether it’s innate or (more probably) learned, and, if it is learned, whether it’s learned from the margay’s mother or on its own.  Learned mimicry (unless it’s an accidental vocalization that’s reinforced) presupposes a theory of feline mind that can reason thus: “If I make a sound like this, I can get a meal.”  I suspect this isn’t just a case of vocal reinforcement, because cats don’t make nonmimetic noises when they’re hunting.

The authors note that rainforest locals have also described deceptive mimicry in the cougar (Puma concolor), the jaguar (Panthera onca), and the ocelot (Leopardus pardalis) preying on tinamous and agoutis, both of which make calls that could be imitated by cats.  These reports should not be dismissed.  Cats, it seems, are even wilier than we thought.

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Calleia, F. d.O., F. Rohe and M. Gordo. 2009.  Hunting strategy of the margay (Leopardus wiedii) to attract the wild pied tamarin (Saguinus bicolor).  Neotropical Primates 16: 32-34.

Two books worth a look

July 10, 2010 • 5:35 pm

Tomorrow’s New York Times Book Review highlights two intriguing books, one on religion and the other on science.

The first is Philip Pullman’s latest, The Good Man Jesus and the Scoundrel Christ, reviewed by none other than Christopher Hitchens.  The novel’s conceit is that Jesus had a twin brother, Christ, and while Jesus was the charismatic one, Christ was the smart one, determined to create a myth around his brother.  Hitchens’s review gives more of the plot, omitting the surprise ending.  Predictably, Pullman’s book has been denounced as profane, and he proffered this response, which I’ve highlighted before.

Hitchens’s review is surprisingly low-key, lacking the zip I’ve come to expect from his pieces.  This may reflect his health problems—or perhaps he’s assumed more gravitas for a NYT review.

The second is The Price of Altruism, Oren Harman’s long awaited biography of population geneticist George R. Price. Price (1922-1975) is famous for developing the “Price equation”, a succinct mathematical formula expressing the conditions under which natural selection would cause a trait to evolve.  The equation gave important insights into the likelihood of evolution via group selection, kin selection, and altruism.  Price was also a bizarre character—an atheist who later became a stalwart Christian, giving his possessions to the poor and helping—and personally housing—the homeless.  He finally committed suicide, slashing his throat with nail scissors.

Harman’s book is reviewed by renowed primatologist Frans de Waal, who likes it.  de Waal explains Price’s accomplishments well, recounting some tales of perfidy in the field, including an account of how John Maynard Smith unethically appropriated other people’s work (I can’t vouch for this claim).

Two plaints about the review. I think de Waal’s explanation of the problem with group selection is a bit unclear, and he skirts the issue of whether altruistic behavior is a direct adaptation or only a byproduct of other adaptations like maternal behavior.  But otherwise it’s a fine review, and I’ll be reading the book.

George R. Price

Nongenetic selection and evolution: flies use bacteria to adapt to parasitic worms

July 10, 2010 • 10:37 am

Evolution by natural selection requires three things:

1.  A trait shows variation

2. The variation in that trait must be capable of being passed on from parents to offspring (i.e., the variation is “heritable”)

3.  The variation in that trait must make a difference in its likelihood of being passed on from parents to offspring. (Usually, but not always, this requires that the trait affect the survival or reproduction of its carrier.)

If all this is true, those forms of a trait that are better at proliferating will gradually increase in a population.

Although these statements are the basis of Richard Dawkins’s book The Selfish Gene, do note that the above characterization doesn’t use the word “gene.”  Even if a trait has a nongenetic basis, it will evolve, via a form of natural selection, if it satisfies these conditions. Much of cultural evolution works in this way, although there are profound difference between cultural evolution based on cultural natural selection (or selection among “memes”) and biological evolution based on genes.

A new paper by John Jaenike and his colleagues in Science, however, shows a form of biological evolution by natural selection that isn’t based on changes in genes. It’s based on changes in the presence of symbiotic bacteria that protect a species from parasites.

The species in which the nongenetic evolution has occurred is the mushroom-feeding fruit fly Drosophila neotestacea in North America:

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Fig. 1. Drosophila neotestacea

In the eastern U.S., this fly is afflicted by a parasitic nematode, Howardula aoronymphium (we’ll call it “the worm”), that renders females sterile, reduces the mating success of males, and reduces the survival of both sexes. (Fig. 2 gives a pretty disgusting picture of a worm-infected fly.) The nematode enters the fly larva when both are the mushroom, and persists in the adult fly.  Females, attempting to lay eggs then pass the nematode into the mushroom, where it mates and enters other fly larvae, completing the lifecycle.


Fig. 2.  D. neotestacea female dissected to show reproductive tract and its huge load of parasitic worms. Photo by J. Adam Fenster, University of Rochester

Based on genetic evidence, the nematode appears to have colonized North America from Europe fairly recently  (American worms have much less genetic variation than European ones, but represent a genetic subsample of them). But the worm is present in fly populations throughout North America, and in every population about 20% of the flies are infected with worms.

Some flies also carry another organism: the bacterial symbiont Spiroplasma, which is found in many insects.  In D. neotestacea, however, the presence of Spiroplasma protects the fly from the sterilizing effects of nematodes.  While flies with worms and no Spiroplasma are virtually sterile, the presence of the bacteria confers almost normal fertility on worm-ridden flies.  It’s not yet clear how this works, but worms in flies with Spiroplasma are much smaller than those without the bacteria. Presumably the bacteria does something to the worms (or to the flies) that makes the worms grow much more slowly.

So this is a good setup for natural selection. First, there is variation in a trait—some flies have Spiroplasma, others do not. That trait is heritable, for Spiroplasma are transmitted directly from mother to offspring in the egg (there’s no “horizontal” adult-to-adult transmission).  And there’s an environmental factor—the parasitic, sterilizing worms—that cause differential reprodution of flies depending on whether or not they carry Spiroplasma.  Those flies who carry Spiroplasma can still produce offspring, and hence pass on the Spiroplasma to the next generation; those flies who don’t carry the bacteria don’t get protection from nematodes, and leave no (or very few) offspring.  In the presence of worms, then, there’s a huge selective advantage in flies to carrying bacteria.

You’d expect, then, that in the presence of worms, the proportion of flies that carry bacteria would increase over time. This is a form of natural selection, but it’s selection on flies that carry bacteria.  Flies with bacteria are the ones who reproduce; they pass those bacteria on to their offspring, and so the proportion of bacteria-carrying flies goes up.  There’s no difference in the DNA of flies who reproduce and those who don’t, so the flies’ genomes themselves are not evolving.

Nor do the bacteria seem to be evolving, although there could theoretically have been mutations in the Spiroplasma that make them kill or inhibit nematodes (after all, any bacteria who could do this would leave more offspring).  But population-genetic studies of the bacteria suggest that this hasn’t happened.  The bacteria seem to confer resistance to nematodes simply through some innate feature of their biology.

What Jaenike et al. found was that the predicted selection occurred, and caused evolutonary change: the proportion of Spiroplasma-infected flies indeed seems to be increasing  within populations in the eastern U.S..  Moreover, the bacteria has started to spread from the eastern to the western U.S. in only three decades.  Here’s the evidence:

  • Museum specimens of flies collected in the eastern U.S. in the early 1980s show no Spiroplasma (you can screen museum specimens for bacterial DNA).  But now, in those same populations, the frequency of flies that carry bacteria ranges from 50% to 80%.
  • Worm-ridden flies collected in New York in the 1980s were largely sterile, having the same fertility profile as modern flies that are worm-ridden and don’t have the bacteria.  But in modern populations, most flies do carry the bacteria and so are fertile even if they have worms.
  • There’s a “cline” (a geographical gradient) in the presence of the bacteria from eastern to western North America.  As I mentioned above,  the proportion of flies with bacteria is high (50-80%) in the east, gets lower (10-25%) across the Great Plains, and is at or near zero in coastal British Columbia.  Given the presence of worms in all of these locations, there would be a strong advantage for the western populations of flies to acquire the bacteria too.
  • Finally, genetic evidence suggests that flies in western North American haven’t yet reached their equilibrium degree of bacterial infection (it should be about 0.8—it’s not complete at equilibrium because transmission of bacteria from mother fly to her offspring isn’t perfect).

All this suggests that the bacteria are in the process of sweeping from east to west in the flies through a natural selection-like process.  All populations of flies have worms, and should thus have bacteria, but the bacteria are just beginning to go west.  This is analogous to a new adaptive mutation working its way through a species.  And you can make a prediction: in another two or three decades, all western populations of flies should have a high frequency of Spiroplasma.

At the end of their paper, Jaenike et al. note that this example may suggest strategies for wiping out nematode-caused diseases like river blindness and filariasis (which produces the grotesque swelling of limbs called elephantiasis).  Those diseases, too, are transmitted by worm-ridden flies, and perhaps deliberate infection of those flies with bacteria like Spiroplasma could reduce the transmission of nematodes and help wipe out these diseases.

Here, then, we see how a species (the fly) has adapted to an environmental challenge not by changing its genes, but by acquiring a whole genome—the Spiroplasma genome.  It’s as if the whole bacterium was an adaptive mutation.  And we also have a case of selection in action, one that makes testable predictions. Creationists may dismiss it since it’s not “evolution” in the traditional sense, but it shows the principles of natural selection in any meaningful sense.

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Jeanike, J., R. Unkless, S. N. Cockburn, L. M. Boelio, S. J. Perlman.  2010.  Adaptation via symbiosis: recent spread of a Drosophila defensive symbiont. Science 329:212-215

Caturday felids: ninja-cat-in-the-box and rickrolling

July 10, 2010 • 5:28 am

This toy will amaze, delight, and puncture your children:

If you’re of a certain age (and by that I mean young), you’ll know what rickrolling is.  You may even have been a victim of this nefarious practice.  It involves luring people to click on a video by promising a particular content, and then, halfway through, the video turns into a performance of Rick Astley singing the obnoxious song, “Never gonna give you up.”  Wikipedia recounts the history of rickrolling pranks.

As an example, here’s one famous and cat-themed rickroll. As described on Wikipedia:

On January 13, 2009, in honor of the new YouTube hub for Congress, U.S. Speaker of the House Nancy Pelosi uploaded a video called “Speaker Pelosi Presents Capitol Cat Cam” to her official YouTube channel. She described it as “a behind the scenes view of the Speaker’s Office in the U.S. Capitol.” The video depicts cats roaming around the office. A rickroll occurs approximately halfway through the video.

Here it is:

That’s a long introduction to today’s second featured video:  kitteh Fro refusing to be rickrolled: