It may seem like a strange question, but it makes sense when you think about it. Dogs and bears kind of look similar, and in their evolutionary history, are they related more than the average person knows? Well, thankfully, science has some great answers on the history and classification of many of earth’s animal species. A bear does sort of look like a large, thick dog, don’t they? Well, let’s find out for certain: Are bears related to dogs?
Are bears related to dogs?
The main question here is one of evolutionary history. When we ask if something is “related,” we are asking if two animal species share a close genetic relative of one another.
To quickly answer the question: Bears are not directly related to dogs. However, they do have an ancient ancestor that was shared between both species. As a second note of equal, if not greater importance, every living thing is related. Humans share a genetic ancestor with jellyfish as well as fungi, but those relations are significantly more distant than the relationship we share with chimps. The real question (and probably a more helpful one) is how closely and how distantly (timewise) are species related.
As you’ll soon discover, the common ancestor of dogs and bears lived 62-32 million years ago. While both animals are mammals, today they’ve branched apart from this common ancestor. Let’s dive into more details of this relationship!
How do we know if something is related?
All questions involving if a species is “related” to another species hinges on evolutionary history. Essentially, what people are asking is, “how far back do these two species share a common ancestor.” Evolutionary study allows us to look back in time (through a few different methods) and put puzzle pieces together, giving us a bigger picture of the genetic heritage that all living creatures share. If you go back far enough, all living things share an ancestor.
There are a few ways that humans have studied different species’ interrelatedness. The most popular one (from a public view) is probably fossil evidence. We can often dig up bones or fossil impressions that clearly identify themselves as some quasi-species that two current (extant) species likely descended from. The most recent connection between two species is known as a common ancestor.
The second and more important way that we can look at shared evolutionary history is through DNA. DNA evidence allows us to look back in time with relative certainty and see how closely things are related. When two species share incredibly similar DNA, it’s likely they are closely related and have a not-too-distant common ancestor.
What is taxonomic classification?
While rather boring, it’s important to understand how scientists classify organisms. Without knowing classifications, we can’t know if something is related! Here is a basic overview of classification.
In order to understand “relatedness” on an evolutionary scale, it’s important to understand the grouping system that humans utilize in order to make sense of things. Taxonomy is simply the science of naming organisms and grouping them into related categories.
Imagine taxonomy as a pyramid with the most general, most encompassing definitions being at the top, and the most specific, most detailed definitions being near the bottom. For example, the six kingdoms (the second most general group) include plants, fungi, animals, and more. The most specific classification, species, includes closely related things like polar bears, grizzly bears, and black bears.
How closely related are dogs and bears?
Now, to get to the immediate question at hand, how closely related are dogs and bears? We established earlier that while they’re not directly related, there are taxonomic classifications that can reveal just how close a relationship is. Now, you may have come across other sources that say they are not closely related. Yet, the truth is that both animals are relatively closely related!
Dogs and bears are both within the suborder Caniformia (literally meaning dog-like carnivorans. This taxonomical classification includes dogs, bears, wolves, foxes, raccoons, and mustelids. Many species (the most specific way of identifying an animal) within this order have non-retractable claws and are generally omnivorous.
This sub-order split from Feliformia (cat-like carnivorans), from which lions, cats, and other felines descended. Within the sub-order Caniformia, nine families currently exist. Dogs and wolves exist within the Canidae family, while bears are classified within the Ursidae family.
So, if you are comparing bears and dogs based on their sub-orders, they are closely related. However, they are fairly related in terms of their families since they belong to different families but share the same sub-order. Lastly, in terms of species, they are distantly related.
In short, dogs and bears are related by sub-order, but their families and species differ. Overall, dogs, wolves, and bears are related by their sub-order and have a shared ancestor that isn’t all that distant.
What is the most recent shared ancestor between bears and dogs?
Now that we understand some of the basics of evolutionary relatedness, let’s look at the most recent common ancestor that bears and dogs share! Remember, this ancestor was the precursor to both bears AND wolves/dogs, as well as a few other families.
The most recent common ancestor between bears and dogs is Miacids. Miacids are extinct and lived between 62-32 million years ago. They were rather successful, surviving for at least 28 million years. These extinct mammals are believed to have evolved into the modern basis for the order Carnivora, of which the sub-order Caniformia and Feliformia diverged. They likely looked like martens and weasels, with some living in the trees and others living on the ground.
Miacids are the basis for all modern carnivores and likely preyed on anything smaller than they were. As these Miacids spread, they began to specialize in their ecological niches. In Africa, where felines developed, the abundance of meat and herd animals likely allowed them to evolve into the superpredators that we know as lions and leopards. In North America and Europe, the need for a more diverse diet led to more omnivorous animals, like what we see with bears, dogs, and otters.