Official Off Topic Discussion Thread #1

[RD.]

Neural crest cells appear to be involved in the process. Another recent article along the same lines, involving raccoons.

City Raccoons Are Evolving to Look More Like Pets

City-dwelling raccoons seem to be evolving a shorter snout—a telltale feature of our pets and other domesticated animals

www.scientificamerican.com

 

[skjl47]

An interesting read regarding dog diversity, and domestication. And how physical changes began 11,000 years ago, not during the 1800’s as commonly believed.

Our dogs' diversity can be traced back to the Stone Age

A new study suggests their physical transformation began much earlier than we previously thought.

www.bbc.com

Hello; Somehow, I have missed the 1800's notion of domestication & selective breeding. While it has been only my imagination, I sort of figured we humans fiddled with dogs early on.
Among my favorite science stories is how new equipment forces us to revise or throw out old established ideas. Telescopes & microscopes are good examples. Every time a better version is invented new evidence has changed understanding.

 

[jjohnwm]

Interesting articles, for sure. It seems like a bit of a reach to call all such changes precursors to "domestication". Tends to imply that along with the physical changes the critters are also becoming friendlier, more cuddly, whatever.

I lived for a number of years in the city of Toronto, and continued to commute there for years after I moved out. It was often said that raccoons were present in higher densities in that city than in any natural environment; seemed very believable, based upon simple direct observation. Those animals were absolutely habituated to people, but they were by no means friendly. I think that using the term "domestication" paints an inaccurate picture of their interaction with us.

They had relatively few sources of natural raccoon food, subsisting almost entirely upon garbage. I wonder if a shortened, broader snout might be in some way linked to an increased need to crush and break open bones to access marrow, which would favour a more robust snout and jaw, in both raccoons and early wolf/dogs?

I commented on this to my wife, who opined that maybe the short, cuddlier-looking face of a city raccoon might slightly reduce the odds of it having its skull caved in by an irate cave dweller...er, sorry, apartment dweller.

Here in rural Manitoba, raccoons are a relative rarity, at least compared to the big city of Toronto. We have squirrels, of course, but they aren't present in the plague numbers of the city. Possums are only present as individuals that have hitchhiked up here on trucks; they don't last long enough to breed at all, let alone evolve. Feral cats...are essentially coyote food; don't see many, and almost never see the same one twice.

Our animal vandals and pests are limited to coyotes, bears and some wolves. Fortunately, in a rural/agricultural setting like ours, almost every hand is raised against them and they learn and maintain a healthy fear and respect for people which serves them and us quite well. Sounds like the eggheads might want to call that a form of "domestication", but...I don't think so.

Among my favorite science stories is how new equipment forces us to revise or throw out old established ideas. Telescopes & microscopes are good examples. Every time a better version is invented new evidence has changed understanding.

Yep, research and technological advancements are constantly forcing us to re-evaluate the things we think we know about reality.

It seems that, at the core of things, there are two types of scientists. The first type, the type that I can admire and listen to and with whom I find myself nodding in agreement, are those who state "We once thought that, but we have since learned new things that have made us now believe this..."

The other type...the ones that I just can't trust...are those who categorically state "We used to think that...but we now know this..." as if their latest beliefs are somehow inviolate and unquestionable. Gotta watch those guys...

 

[RD.]

I wonder if a shortened, broader snout might be in some way linked to an increased need to crush and break open bones to access marrow, which would favour a more robust snout and jaw, in both raccoons and early wolf/dogs?

I suspect that in both dogs, and raccoons, it may have had more to do with less tearing, and more chewing, of non meat items. Once carb consumption increased, which seems to be the case, a change in jaw structure would follow. This same type of morph can be seen in some of the cichlid species in the Crater Lakes of Central America. Also, at the same time, there would have likely been an increase in enzyme activity, such as amylase production, which would have allowed better digstibilty and overall bioavailability of those carbs/ grains/starch, that make up a large part human diets.

 

[jjohnwm]

Ah! So...junk-food-adapted-raccoons?

Would those ideas also extend back to early humans? It seems that the association of early humans and early dog-like wolves would predate the increase in the human diet of those items? Or no?

It's all interesting stuff, although pretty much academic at this point. I'm also curious as to the emotional attachment that can form between humans and dogs, or even...I shudder to think...humans and cats...

The dogs, being social animals, would naturally fall into the notion that they were part of our pack. The cats, being more solitary, seem harder to explain in that regard. And there is a surprising variation amongst humans themselves in the degree to which they can bond with their animals. Dog people...cat people...folks who feel nothing for either species...weird stuff.

 

[Conchonius]

As I understand it, the human adaptation to junk food far predates human-dog interactions and in fact is proposed as a reason that we became so smart to begin with. Because we had the means to crack bones and cook food, we could make use of calories that other animals couldn't easily access, justifying the development of big, energy-hungry brains.

This "self-domestication" is also a potential reason for our own shorter faces (you don't need to crush as many foods when you have hands and fire to help you) and the lower level of violence we exhibit compared to chimpanzees. There are plenty of murder stories in the news, true, but that's because there's eight billion of us running around. The collective name for a group of eight billion chimps is bloodbath.

As for behavior, I recall that dogs have the capacity to "defer" problems, i.e. if they encounter something new or unexpected, they will turn to the nearest familiar person and rely on them to solve it. Wolves have no ability to do this: they will not turn to another wolf for help, and will use their own wits to solve the issue. People in turn have the natural ability to read the body language of a dog: we can and do often make mistakes for cats, rabbits, reptiles, fish etc. being defensive, sick, injured etc., but anyone can listen to the bark of a dog and tell you whether it wants to play or is telling you to back off, even if they aren't at all familiar with dogs.

Funny that you should say that dogs learned to identify with our pack, though. There's an idea that it was the other way around: early humans either scavenged or hunted rabbit-sized prey individually. Only through association with early dogs did we gain the ability to take down larger game, and this association promoted greater cooperation and group-hunting, turning us from corpse-pickers to mammoth-slayers. So maybe wolves didn't join our packs, because we didn't really have packs back then - we got the idea from them.

 

[jjohnwm]

Amazing ideas, I have fallen far behind in my reading. Lots to consider.

We would have needed that big energy-hungry brain to master tools and fire and all those other accomplishments, so hard to say that one allowed the development of the other. Probably not possible to clearly say which came first...the smarts or the tools.

The idea of humans learning from and joining with wolves is completely new to me. Wolves can't be as smart as we give them credit for; if they were they never would have put up with us back then. And, of course, my old-school "human bias" would never have allowed me to come up with that notion on my own. Not sure I completely buy into it now, and I wonder how universally that idea will come to be accepted.

My energy-hungry brain is currently engaging in these flights of fancy as I sit quietly concealed along a forest trail, awaiting a mammoth...or a deer. I'm cold, wet, cramped, tired, thirsty...meanwhile my dog Duke is lazing in front of the woodstove back home. At this moment it's not hard to believe I could learn a great deal from him.

 

[Conchonius]

Oh, wolves are plenty smart: you might have heard that, after their association with us turned some of their cousins into chihuahuas, they gave up on people and struck a partnership with ravens. When a raven finds suitable prey that it cannot kill but a wolf pack can, a wounded or sick deer perhaps, it calls out to any wolves in the area, and is allowed to take its fill of the resulting carcass. Because of this wolf packs tend not to harm ravens, and in fact play with them at times.

But I think we can maintain some of our pride. My understanding is that, even in the most pro-wolf theories, our "joining" of wolf-packs is less in the way of Mowgli and more about us making good use of the increased capabilities early dogs provided us. "He who sleeps with the blind wakes cross-eyed", says common wisdom in my part of the world, so perhaps we naturally ended up more wolf-like in our social hierarchy after we also started to hunt big prey in packs. An example of evolutionary convergence, or the notion that similar problems produce similar solutions, rather than consciously learning from or imitating wolves.

That said, I am not up-to-date on my anthropology either, so I don't know which is the prevailing idea.

Edit: Another factor to consider is that gray wolves do not occur in sub-Saharan Africa, and domestic dogs only entered the area relatively recently. Yet many SSA tribes make great use of hunting dogs, which supports human ingenuity rather than co-evolution as the driving factor in our association with dogs.