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.