I'll look at our family's pets for examples. This hypothesis is prompted by Benvolio Fish:
I left for the weekend, and when I came home, Benvolio was, like, horrifyingly fat. Unfortunately, I forgot to tell one roommate that the other roommate was feeding him, so he got fed twice a day. And I think the one roommate, whom I did not instruct on how to feed him, fed him rather a lot. AND HE ATE ALL OF IT. This led me to a realization: Benvolio can't tell when he's eaten enough, or too much, so I have to regulate that for him. My hypothesis is based on the fact that bettas are ridiculously overbred. Soooo many health problems can result from the slightest change in water temperature, or pH, or food intake, or stress level. He wouldn't last a week in the wild. I think that somewhere along the line of single-trait breeding for longer fins and specific colors, the instinct to regulate their own diet got bred out of bettas. Weird crap like that can happen when you breed for one or two specific traits. (Ask me for more on this if you want, cuz it's interesting but kind of a tangent.)
In contrast, Spats:
She is a growing kitty, and she eats SO MUCH. When we first got her, she ate more than Smudge and Bubblegum combined, and she hasn't really slowed down since. But she knows what she's doing: she's perfectly healthy, not overweight at all. For the enormous amount of energy she spends playing all day and not sleeping 18 hours a day like a normal cat, she knows that she needs a lot of food.
This is what makes me wonder: are cats fully domesticated? They still know how to take care of themselves. I don't know, though, whether they would be able to survive without humans. Even feral cats still eat out of humans' garbage. They still have the instinct to hunt, but would they be able to catch enough food to live off of?
I've heard that dogs (wolves) started being domesticated (several thousand years ago) when they started following humans around and eating their scraps. Eventually, they started being friendly enough to form a symbiotic relationship with humans, helping them hunt and then sharing the meat. And then we got these things:
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| I don't think this is a symbiotic relationship anymore... |
What do you think? You quite possibly know more about this than me.
Love, Dory
Oooh, good post! You're right about the short answer to what it means to be domesticated is that the species can't survive without human intervention. However, this doesn't necessarily mean direct intervention, like providing shelter or making sure they're eating the right kind and the right amount of food (though that is part of it). I'll use the example of cats, since I happen to know a lot about them (heh). Modern domesticated house cats are directly descended from the African wild cat. These cats started following humans around right around the same time that dogs did, living not so much off of the scraps left behind, but the rats who were after the scraps. Our earliest ancestors were largely nomadic, moving around from place to place in search of food and hospitable places to set up camp for a while. Often, the humans were just one step ahead of the rats.
ReplyDeleteEventually humans began domesticating plants. The first plant to be effectively domesticated was a type of grass, which was selectively bred for traits like a strong stalk and seeds with a hard shell so that they wouldn't break off in the wind. This grass eventually became what we recognize as corn. Corn doesn't grow in the wild, because it evolved to suit a human-controlled environment, with specific amounts of moisture, sunlight, and pest control. It's a totally man-made species -- but that's a bit of a tangent.
When people domesticated plants, it was only natural for them to start setting up permanent settlements. One of the biggest bummers about staying in one place is having the rats catch up to you. Luckily for our ancestors, the cats were there to play the role of pest control, which not only kept the rats at bay, it effectively prevented the spread of the diseases they carried. What this meant for the cats was that they had a reliable source of food, shelter, and as it turned out they kind of liked humans and we kind of liked them.
As you pointed out, cats do still have the instinct to hunt. The problem is, they don't associate that drive with food. While they will still sometimes kill and eat things, when their belly starts to grumble their first thought is to go to their food bowl. They don't know to hunt when they have that feeling, because hunting for food is a learned behavior that they are taught as kittens by their mothers. This is why big cats who are raised in captivity can never be released in the wild. Feral cats who have kittens will teach those kittens not how to hunt, but how to scavenge, because that's the most effective way of getting food in an urban environment. When we put cat food out for our kitties, we are also teaching them how to scavenge, because they don't have to kill anything to get to it.
So what we did back in the day was essentially isolate a handful of a certain species, and they bred in conditions that effected the way subsequent generations evolved, creating a sub-species. So the modern domesticated cats we know and love actually have no natural environment, or else their natural habitat IS the urban environment; therefore they are considered fully domesticated.
Also, I have always been perplexed as to where someone found a wolf with fur like that poodle, in order to breed for that trait. And one with floppy ears, and one with a squished face. It's just mind-boggling to think about... :P
ReplyDeleteAnd I'm thinking about what you mentioned about how intensive single-trait breeding can cause problems with what I assume is the fishy's immune system? It reminds be of how Bengal tigers who are born with the "white tiger" pigmentation tend to grow up to be about 30% larger than their siblings, whether male or female. You wouldn't think something like hair and eye pigmentation would effect something like adult size, but bodies are connected in surprising ways sometimes. It kind of makes you want to *facepalm* at how much selective breeding people have done in the past with absolutely NO knowledge of these things.
srsly, *facepalm.* The first time I heard about what problems single-trait breeding can cause, it was with chickens who were being bred to have larger muscles in their chests that would result in bigger chicken breasts to be sold. Somehow, at a certain commercial farm, in the midst of this single-trait breeding, the roosters ended up losing their instinct to do their mating dance. Chickens are programmed thusly: males do mating dance, females, if pleased, then allow the males to mate with them. But if the rooster doesn't do the mating dance, the hen won't allow anything of the kind. So on this particular farm, there were some horny males who didn't know to do the mating dance. So when the hens refused them, the roosters would then, I'm not even joking, rape and kill them. So screwed up. DNA is so weird.
ReplyDeleteThis story was in this book:
http://www.amazon.com/Animals-Translation-Mysteries-Autism-Behavior/dp/0156031442/ref=sr_1_1?ie=UTF8&qid=1316548152&sr=8-1
Which is super interesting if you're looking for a bit of light reading. :d
Oh my goodness! Does it make me a bad person if that horrifying story made me lol? Particularly this part: "males do mating dance, females, if pleased, then allow the males to mate with them."
ReplyDeleteI shall check out that book!
hahaha, totally understandable. My attempt at delicate wording didn't help at all.:P
ReplyDeleteOn a semi-related note, mating dances seem to be a pretty common thing in the bird world. I wonder if dinosaurs did mating dances?
ReplyDeleteOh! I just stumbled this video, and it could be relevant... Baboons are much more distantly related to us than chimps, but this is mega interesting:
ReplyDeletewww.youtube.com/watch%253Fv%253DU2lSZPTa3ho
Got a 404 error :( Are you sure that link is right?
ReplyDeleteOooops! http://www.youtube.com/watch?v=7I7-SADai3Y
ReplyDeleteThat is so odd! I never thought of keeping pets as anything but a human phenomenon.
ReplyDeleteI'd heard of isolated cases of primates (and even other animals, like wolves, leopards, or squirrels) raising young of another species, but never in a deliberately pet-like way. It's really interesting -- gives some insight into the ways in which dogs may have aided early humans!
ReplyDelete