Evolution: The Curious Case of Dogs | Hacker News Reader

Evolution: The Curious Case of Dogs

scienceblogs.com

77 pointstokenadult24 comments

"The most impressive beggars, however, get their own title: 'metro dogs'. They rely on scraps of food from the daily commuters who travel the public transportation system. To do so, the dogs have learned to navigate the subway. They know stops by name, and integrate a number of specific stations into their territories."

Score another one for science fiction. SF writers have talked about city-specialized animals emerging for a while now, and while you could certainly say that some critters have adapted nicely (pigeons, squirrels, depending on the degree of urbanization), dogs that know how to use crossing signals is, IMHO, a higher level.

See also their symbiotic protection of the inner city from the vicious dogs. Note that had the politicians decided to be rid of them, that would have been the end of them, so they actually passed a selection criterion there. Humans have, at least for now, accepted this breed as symbionts at the urban level. One could easily imagine them further specializing rather quickly, if they are not wiped out.

I think the best example of just how fast evoltion can be is the domesticated silver fox: http://en.wikipedia.org/wiki/Domesticated_silver_fox

Video: http://www.youtube.com/watch?v=enrLSfxTqZ0&feature=relat...

http://www.youtube.com/watch?v=gxFKKf5B2BE

Thanks. I've read about that experiment before, and I thought it was fascinating. But I had never actually seen the domesticated foxes, and I hadn't realize how freaking adorable they'd be.

I saw a TV programme about this, maybe 10-15 years ago and it dawned on me then that the scariest part of this was that it would only take the same amount of breeding to make humans as domesticated as this. Reminds me of S.M. Sterling's Draka novels. http://en.wikipedia.org/wiki/The_Domination

Probably not true. Dogs - the species - have a large amount of genetic variation. There's a lot to play with. Humans do not have as nearly as much genetic variety across the species. A stat I read is that there's more genetic variety in a group of 50 chimps than in the entire human species.

This points to a genetic bottleneck in the past 100,000 years or so. Our ancestors were the few survivors of some catastrophic event.

Humans are domesticated relative to our ancestors / closest primate relatives. Anyway, I suspect the reason domestication works so fast is it's breaking down a chemical pathway which is fairly simple relative to creating a new sequence. Most young animals are minimally aggressive as baby's and it's only after they start to grow that they become aggressive. So just about any mutation effecting that transition sequence and they stay as infants.

What makes you think that humans are not already domesticated?

If multicoloured coats were a development in domesticated wolves and foxes, then are humans really that far away? We went from a species with a very limited 'coat' colour, to everything from a near-white to black and all the natural pigment colours between.

I myself have four pigments to my beard, red/blonde/golden-brown/dark-brown. Only a few dozen generations ago when my ancestors didn't live in mega-communities on the order of millions, but lived in a community of a few hundred they likely had black hair between them all.

We're a predator species that is capable of living in numbers (without outside intervention) only surpassed by migratory birds and butterflies. We're not domesticated, because our purpose hasn't been changed to fit another species needs, however I would say with have been made extremely docile compared to our ancestors.

Anyone who's seen a new york city rat ascend from and descend into the cracks between the tracks at just the right time to avoid being squished can attest to this as well.

It's happening in London. There are pigeons who ride the London underground for years now ( http://london-underground.blogspot.com/2003_12_01_london-und... ), and here's a recent photo of a fox on a London Underground Escalator. http://www.metro.co.uk/weird/805065-tube-fox-tries-to-take-a...

Attenborough and crows in the crosswalk:

http://www.youtube.com/watch?v=BGPGknpq3e0

Impressive, yes, but they're not the first self-domesticating species.

Cats pulled this stunt 10,000 years ago.

"This dramatic shift from the survival of the fittest to the survival of the smartest..."

It really bugs me when people use terms like this. Survival of the smartest is survival of the fittest. Nothing has changed!

Selection pressures have changed, but, yes, it's still "fitness." It's just that the criteria of "fittest" in that situation has changed. I think people conflate "fittest" with "physically fit" which is not what the word means in "survival of the fittest."

What's funny is that the phrase itself is something of a tautology -- fitness in that context is basically having whatever attributes contribute to survival, so the phrase ends up meaning "survival of that which survives best" or even simpler, "survival of the survivors". Survival is the only measurable quality of fitness.

The other thing that can be confusing is that the timeframe of the statement is infinite. It's not saying "that which is still alive today is the fittest", but rather "that which is still alive infinitely far into the future is the fittest".

http://en.wikipedia.org/wiki/Survival_of_the_fittest

"Darwin first used Spencer's new phrase 'survival of the fittest' as a synonym for 'natural selection' in the fifth edition of On the Origin of Species, published in 1869.[2][3] Darwin meant it is a metaphor for 'better adapted for immediate, local environment', not the common inference of 'in the best physical shape' [4]. Hence, it is not a scientific description,[5] and is both incomplete and misleading."

More importantly, people consider people to be apart from nature. Everyone would agree that dogs have undergone artificial selection- selection controlled by humans. But from a grand-scheme-of-things point of view, humans are just another force of nature, thus it's really just the same old natural selection, survival of the fittest. We just like to think we are something other than nature.

Indeed. The selection dogs have undergone is not, in the final analysis, artificial. The many breeds of dogs are simply seeking out ecological niches in a complex fitness landscape which humans partly define.

I'm not even sure the selection process is all that different from nature's. Is an odd feature in a pet striking a fancy all that different from an odd feature in a mate doing so?

Indeed it is -- fixing traits (creating homozygosity) in standard breeds involves intense inbreeding, which also makes normally-recessive and harmful traits much more likely to be expressed than in any natural pattern (inbreeding is normally abhorred by nature). Purebred dogs are far more likely to fall victim to cancers, hip displasia and other ailments that would naturally be selected against.

There is also a good excerpt about the evolution of dogs from Richard Dawkins:

http://entertainment.timesonline.co.uk/tol/arts_and_entertai...

This reminds me of City by Clifford Simak, nice story. http://en.wikipedia.org/wiki/City_(novel)

I'm part way through that book at the moment. It's a good read.

>> you don't see many Chihuahua/Saint Bernard mixes

I'm not so sure about that. My sister once had a Chihuahua/Husky mix that she got from a Russian circus. She looked like a small Husky with brown and white fur. (The dog not my sister.)

Though sometimes "you don't see many" is used to imply "because none exist," it doesn't literally mean so. Just because she had a Chihuahua/Husky mix doesn't mean that they aren't rare.

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