Gene Expression

Genetic closeness != behavioral closeness

Sheril’s post, Chimpanzees Are NOT Pets!, is good. She notes:

1 Chimpanzees are wild animals. Animals that make good PETS like dogs and cats, have been domesticated for [thousands] of years. There has been selection on them against aggression, which is why a dog, unlike a wolf, will not automatically tear you to pieces. Anyone who has a pet chimpanzee for long enough will eventually no longer be able to control them and will either get a body part bitten off or will have to use extreme force to control them. Chimps live to be 50 years old and grow almost as big as a human male. They have extremely powerful muscles and are 5-10 stronger than a heavy weight boxer.

There is some more nuance to this.

1) Dog breeds differ in temperament, so not all are equally fluent in the ways of man

2) Dogs can read human faces:

Dogs are more skillful than great apes at a number of tasks in which they must read human communicative signals indicating the location of hidden food. In this study, we found that wolves who were raised by humans do not show these same skills, whereas domestic dog puppies only a few weeks old, even those that have had little human contact, do show these skills. These findings suggest that during the process of domestication, dogs have been selected for a set of social-cognitive abilities that enable them to communicate with humans in unique ways.

The domestic dog has been selected to be our best friend. Cats are perhaps a different matter, but due to their relative aloofness and small size “misunderstandings” are less problematic than they would be with a Great Dane. In any case, H. sapiens is a relatively gracile ape, our closest relatives the chimpanzees can tear us apart, quite literally. Travis, the chimp who maimed a woman and was killed clearly had a history of acting out. His owner also seemed to have an inappropriate emotional relationship to him.

Comments

  1. #1 Donna B.
    February 20, 2009

    I have little sympathy with the owner of the chimp, but great sympathy for her friend who tried to help (though I wonder about her trusting nature) and some sympathy for the chimp, who may have just been acting like a chimp, or might have been suffering a mental illness due to his owner’s “raising” of him.

    We have two large dogs, one is a pound puppy, probably a husky, lab, shepherd mix. We know nothing about his lineage. I worry a bit more about this dog’s behavior than I do our other dog, a Great Pyrenees whose ma and pa (and their temperaments) are known.

    We do not let these dogs run loose, though they have escaped a time or two. We have, hopefully, fixed their escape routes. They are never out of their pen or out of our house without a leash on, and we’ve had professional help in training them.

    While I think we have decent “pack control” going on for us at the moment, we have discussed trying to find better homes for the dogs because, at our age, we are too easily overpowered by these young animals.

    I truly cannot comprehend the level of attachment this woman had to the chimp – definitely not healthy for either of them. I also do not understand letting an animal, domesticated and trained or not, roam free as this chimp was apparently allowed to do on occasion.

    That said, I’m also against the knee-jerk “there ought to be a law” gang. I’m afraid we will see laws that will inhibit care for chimps rather than laws that prevent human abuse of them.

  2. #2 tdaxp
    February 20, 2009

    Ironically, the conclusion of the reposted blog post makes a similar fallacy… genetic closeness == spiritual closeness…

    “We don’t buy and sell people any more. Since chimps and bonobos share 98.7% of our DNA, don’t they deserve the same respect?”

  3. #3 Joshua Zelinsky
    February 20, 2009

    The genetic closeness point can’t be hammered home enough. There are single alleles which can cause massive differences in human behavior and handfuls of genes which can cause retardation or other problems. Chimps have many genetic differences.

    (Incidentally, a wolf won’t actually automatically tear you to pieces. It will however do so with minimal hesitation if it is a) hungry or b) feels even slightly threatened)

  4. #4 John Emerson
    February 20, 2009

    The Smithsonian Magazine (Jan. 1991) had a great article about this, which doesn’t seem to be on the internet. A Siberian fox breeder selected the friendliest fox puppy from each litter and bred these apart from the others. After about ten generations he had a tame fox.

    Something like this was conjectured to explain the original taming. Perhaps generations of some canine developed the habit of hanging around hunter-gatherer encampments and scavenging, and maybe this was allowed for religious or superstitious reasons. Or perhaps they followed hunters and scavenged the leavings, and hunters found that canines are good at flushing and spotting game.

    In the Siberia experiment, the tame foxes exibhited neonatony (sp?), and kept puppylike traits into adulthood — barking was one, big ears another — and as social pack animals bonded to humans.

    Dogs are insanely trusting of their masters. They’re really emotional cripples, but they do make you feel good about yourself.

  5. #5 Eric J. Johnson
    February 20, 2009

    “The total muscle mass of an adult chimpanzee is only about one third that of an adult human male. But chimpanzees can exert over twice the force that humans can for certain motions. The reason is that the point of attachment between the biceps and the forearm is further from the elbow in chimps than in humans, hence the chimp’s mechanincal advantage (d2/d1) is greater. Never arm
    wrestle a chimpanzee!”

  6. #6 Jason Malloy
    February 20, 2009

    “Anyone who has a pet chimpanzee for long enough will eventually no longer be able to control them and will either get a body part bitten off or will have to use extreme force to control them.”

    Sounds like a dubious assertion to me. “[U]p to 400 chimpanzees are kept as pets in the U.S.”; I’m sure there are more in Europe. Yet this is one of the few stories about a pet chimp mauling someone to hit the news (there was another big incident several years back, but those were more like zoo chimps than “pets”). So what is the real basis behind the claim?

    I would bet there is no difference in loyalty/danger towards owners between dogs and chimps raised from infancy. I’m just going to dismiss that most chimpanzee owners will “get a body part bitten off”. Change it to “almost none”.

    The second claim is more defensible. A more obvious consequence of domestication (for both post-agricultural humans and wild animals) is tolerance for strangers. Most dogs are probably fully safe around relative strangers, while most human-socialized chimps are not fully safe. I can’t say what the odds are for a pet chimp doing something horrible though, but it is certainly far short of the suggestion that all of them eventually seriously hurt someone.

    Incidentally, my first childhood dog eventually had to be put to sleep because it had a nasty habit of escaping and attacking neighborhood children. At one point it bit the nose off of one my mother’s friends. It was hanging off of his face like a flap.

    The dog was also neutered, so perhaps social domestication of the dog continues apace.

  7. #7 Charles Iliya Krempeaux
    February 20, 2009

    Chimpanzees are wild animals. Animals that make good PETS like dogs and cats, have been domesticated for [thousands] of years. There has been selection on them against aggression, which is why a dog, unlike a wolf, will not automatically tear you to pieces

    Was I the only one who thought it might be (intellectually) interesting to selectively breed Chimpanzees for tameness?! (I.e., something similar to the: Tame Silver Fox.)

    (And please, no Planet of the Ape jokes.)

    You could get “good” Chimpanzee pets that way.

  8. #8 John Emerson
    February 20, 2009

    Neoteny.

    I think that that was a flaw in Diamond’s argument that certain large animals (elands, deer) were too wild to be trained as draft animals or raised for meat. The experiments he referred to didn’t selectively breed for many generations. My guess that wild caribou can’t be tamed the way domestic reindeer can (same species).

  9. #9 razib
    February 20, 2009

    Was I the only one who thought it might be (intellectually) interesting to selectively breed Chimpanzees for tameness?! (I.e., something similar to the: Tame Silver Fox.)

    breed too slowly. though i guess genetic techniques might be able to find particular tame individuals.

  10. #10 John Emerson
    February 20, 2009

    Tame Fox
    Fox breeding project.

    Apparently the project is not doing well financially. Looks like an entrepreneurial opportunity. In Hollywood you might get $5,000 for one pup.

    And I was wrong: it was a geneticist, not a fur farmer, who bred the fox. Maybe he sold pelts to meet expenses.

  11. #11 Charles Iliya Krempeaux
    February 20, 2009

    Regarding the tame silver foxes… as I understand it, they also breed an aggressive silver fox breed in addition to the tame breed.

    I’ve been curious as to the nature of the aggressive silver foxes. Did they also physically change? And if so how? Did they find higher levels of adrenaline in the aggressive ones? Was anything else interesting discovered about them?

  12. #12 justme
    February 20, 2009

    I get how the aggression in chimps hasn’t been bred away, as it has in dogs and cats. What I would like to know is how they’re so much stronger than equivalently sized, or even larger humans; why this fact isn’t more widely known (I didn’t know); and why it doesn’t register on longtime owners simply through experience relatively early during ownership). Alternatively, is it just that when aggressive they exhibit superhuman strength? Because humans also occasionally exhibit superhuman strength in extreme fight-or-flight type situations.

  13. #13 razib
    February 20, 2009

    justme, chimps aren’t strong, we’re just really wimpy.

  14. #14 Eric J. Johnson
    February 20, 2009

    > What I would like to know is how they’re so much stronger

    See my comment above.

    I wonder why our mechanical advantage is lower, and where the MA of the other apes stacks up. Especially gorillas since they climb less.

    I guess a chimp cannot deliver a hard punch. Or move its unloaded limbs as rapidly as a person, in general. I would also guess you would run slower if you had higher MA on every muscle – but I’m really not sure. Obviously a high MA rocks for climbing trees.

  15. #15 jay
    February 20, 2009

    If you and your cat exchanged sizes, you’d be dinner

  16. #16 justme
    February 20, 2009

    OK, let me try. Humans are extremely bipedal, chimps are much less so. Thus there’s a much greater asymmetry in upper and lower limb strength in humans than in chimps. If human arms were about as strong as human legs, then chimps would be about as strong as humans their own size. Some paralympians who have lost their lower limbs do develop upper limbs about as strong as other peoples’ legs. The other thing is dexterity – most humans have almost no dexterity in their lower limbs – chimps do. This gives them the ability to do things such as swing off their legs, and/or anchor and/or pivot off of them, which gains them greater mechanical advantage over humans from applying about the same amount of physical force from the lower body.

  17. #17 Pincher Martin
    February 20, 2009

    Jason,

    Yet this is one of the few stories about a pet chimp mauling someone to hit the news (there was another big incident several years back, but those were more like zoo chimps than “pets”). So what is the real basis behind the claim?

    I’m sure there is no evidentiary basis for the claim, but I would guess it’s still accurate. Owners of exotic animals are certainly very leery of the authorities hearing of an attack and taking away their animals. So the attacks either go unreported or are filed as something else.

    There was a famous case of a tiger mauling his owner a few years back in NYC. The owner originally claimed to docters that his wounds were inflicted by a pit bull. I’m sure that kind of misreporting happens quite often. The police only checked it out because neighbors of the man tipped them off that a large tiger was in the man’s apartment.

    Even in the wild you can get lucky for a long time before the odds catch up with you. Witness Timothy Treadwell, who was able to survive about a dozen summers doing the most outrageous things with grizzlies before one of them made a meal out of him.

  18. #18 Eric J. Johnson
    February 20, 2009

    I think you miss the point – MA has a very precise definition relating to lever-fulcrum systems, which doesn’t involve dexterity.

    If you aren’t an athlete or soldier, you can probably lift 20-60 lbs up toward your face by doing a bicep curl with one arm (ie, bending at the elbow). But if you could take your bicep out and hang it from the ceiling, your bicep could lift 120-360 lbs a few inches off the floor if it attached to the load directly. Because the bicep attaches about 1/7 of the way between your elbow (fulcrum) and the weight in your hand, its strength is multiplied by 1/6, and your hand moves 6 inches for every inch the bicep contracts – a mechanical advantage of 1/6. If you flex your arm and press the inside of your elbow, you can feel the tendon that attaches the bicep to the bones of the forearm. In a chimp it attaches quite a bit farther out relative to the forearm length, so the lever MA is higher.

    If you could hang your quadricep or hamstring from the ceiling I bet it could lift a small car off the ground if attached directly! Not sure though. (A very small car weighs about 2000 lbs. I once lifted one with about 20 people helping, cause it had driven off the road or run out of gas or something, I forget.)

  19. #19 windy
    February 21, 2009

    Sounds like a dubious assertion to me. “[U]p to 400 chimpanzees are kept as pets in the U.S.”; I’m sure there are more in Europe. Yet this is one of the few stories about a pet chimp mauling someone to hit the news (there was another big incident several years back, but those were more like zoo chimps than “pets”). So what is the real basis behind the claim?

    What I’ve heard is that pet chimps are acquired as infants, but then the owners usually have to get rid of them in or after adolescence.

    Here’s one sanctuary:

    Over the past 20 years, owners who have purchased infant apes have said time and time again that they will be different and keep their apes forever, because they are dearly loved. But when the reality hits that it is extremely difficult to keep a super-strong, 150 to 200-pound dangerous adult ape in the confines of a private home, these owners are suddenly and desperately looking for someone else to take on the care and responsibility of their once-beloved “son” or “daughter”.
    Currently, we have a waiting list of 12 adolescent and adult chimpanzees whose owners are asking us to take in at the sanctuary.

  20. #20 Tom Bri
    February 21, 2009

    Well, it just isn’t a surprise that the occasional chimp kills or maims someone. They are pretty closely related to humans after all, and you can read in the paper every day about some human doing as bad or worse.

    Humans are at best only partially ‘domesticated’ though the process goes on. When you look at murder victims they are quite often also criminals. The violent are killing off the violent, leaving the less violent to breed. Diamond talked about this process in Guns Germs and Steel, I believe.

  21. #21 Blind Squirrel FCD
    February 21, 2009

    (Incidentally, a wolf won’t actually automatically tear you to pieces. It will however do so with minimal hesitation if it is a) hungry or b) feels even slightly threatened)

    I don’t know where you are getting your wolves from, but the ones in Northern Minnesota, where I live run in terror or watch curiously when encountering a human. There has been no recorded attack on a human by a healthy wolf in North America.

  22. #22 John Emerson
    February 21, 2009

    Hunters have been culling brave wolves for a long time.

    The American carnivores that do attack humans are cougars and grizzly (not black) bears.

  23. #23 Peep
    February 22, 2009

    Both the wolf and chimp comparisons with man in terms of weakness in a fight ignore that man’s natural state is to be armed with weapons with sharp points and sharp edges and to be trained and proficient in their use since childhood.

    We’re talking about the species that (probably) hunted MAMMOTHS to extinction, top of the food chain wherever hunter gatherer societies are still found. I don’t think that the hunter gatherers that live near them view going on a chimp hunt as some equivalent of the D-Day landings in terms of bravery.

    I reckon that those in an ancient Roman arena would want their money back if given an armed gladiator versus one chimp or armed gladiator versus one wolf fight. As I understand it the dogs used in the arenas, of which the closest living breed is probably the English Mastiff (they were massive molassers adapted from Middle Eastern war dogs), would probably best a wolf in a fight, and were generally used in packs rather than singly in contests. Indeed I would be willing to put down money that a pit bull terrier would probably beat a wolf ceteris paribus despite the size and weight difference. Dog fights are largely about endurance and a certain type of temperament. Though it’s an old cliche about “the size of the dog in the fight” it is actually largely true. I think that a wolf would be pretty meh in dog fighting, or man fighting if it still occurred, or even one on one fighting anything much, they’re cursorial hunters not mano-a-mano killing machines. They just aren’t that dangerous.

    Point being, don’t underestimate a man in a fight when he has the tools that evolution has specifically adapted him to use. Human beings are pretty darn deadly, and if you’re a chimp or a wolf and you see one your best strategy would almost always be avoidance, even if we’re talking about a human still in the stone age.

  24. #24 Peep
    February 22, 2009

    As a more precise wolf / dog comparison, the Caucasian Ovcharka working breed, famous in Germany for it’s use in patrolling the Berlin Wall, is reputed to be capable of fighting off 3 or 4 wolves at a time. The old Irish Wolfhound breed, though arguably not that close to the modern equivalent, was supposed to be capable of reliably beating a wolf or boar one-on-one.

    http://www.dogbreedinfo.com/caucasianowtcharka.htm

  25. #25 Blind Squirrel FCD
    February 22, 2009

    Hunters have been culling brave wolves for a long time.

    The American carnivores that do attack humans are cougars and grizzly (not black) bears.

    Wrong on both counts. Check out the white wolves on Ellesmere Island. Never hunted, and as curious and friendly as kittens. Also Wikipedia lists deaths from grizzly and black bears since 1900 as equal, 50 each.