No one would claim the giant panda isn’t a truly unique animal.
Ever since the panda’s discovery by the Western world in the 1800s, debates have raged about where in the tree of life our black and white friend sits.
Sometimes described as a ‘living fossil’, the panda represents a particularly adventurous jump from evolution, leaving it the sole member of its genus the Ailuropoda.
Today it’s largely accepted that genus is part of the subfamily Ailuropodinae and part of the broader Ursidae family (also known as the bear family).
But it hasn’t always been seen as that straightforward and there are still some in the scientific community that debate the giant panda’s bear-ness today.
How do we define what an animal is?
Why is there even a debate over where the panda sits in the tree of life? And for that matter, what is the tree of life?
Scientists who study nature really, really like to categorize things. Having a taxonomy (a system for naming things) to help us keep track of all the complexity of the world can be really useful.
For animals we use a binomial nomenclature where all animals have two names, both in latin, that place them somewhere in the tree of life.
So, for example, the panda’s two names are Ailuropoda melanoleuca – which denotes their genus and their individual classification.
All animals have a genus and all genuses belond to a subfamily and then family. This is where bears come in. Bear is actually an animal family and includes the panda, polar, brown, black and grizzly bears (and a few others too!).
There’s quite a few levels beyond that, so we’ll list them if you want to read more later, but we won’t go into detail.
Families belong to orders, orders belong to classes, classes to phylums, phlums make up kingdoms, kingdoms all fit into domains and domains make up all of life. Phew!
To make it even more complicated, there are subclasses and suborders and even more subdivisions at nearly all levels of the taxonomic rank system.
So, how do we decide on what family or order an animal should belong to?
Classification is an evolving and often debated topic, with it sometimes taking years for newly discovered life to settle into an agreed upon place in the tree of life.
This is exactly what has happened in the past (and sometimes still happens today) with the giant panda.
Because pandas have so many unique characteristics, it can be hard to find common ground between them and other animals. So it’s not always been obvious which family they make most sense belonging to.
What makes a bear?
Bears are classified as part of the bear family, Ursidae, using a collection of physical and behavioural characteristics.
First, and perhaps most recognizably, bears are usually large, powerful creatures. They have stocky builds with strong limbs and are nearly always well muscled.
Bears are omnivores, with uniquely shaped teeth that include both strong canines and broad molars, suitable for eating either meat or vegetation.
Bears are usually pregnants for a long time and typically have a small number of offspring (called cubs in the bear family). Mother bears will care for their young in the first few years of life.
Bears are not incredibly social animals, often prefering to live in solitude for most of the year.
Nearly all bears hibernate (not the panda!) but some instead simply migrate or change their environment during the year to deal with changing temperatures.
How did the giant panda evolve?
The modern day giant panda is part of a unique subfamily of the bear that split off from other bears approximately 20-30 million years ago.
Today the giant panda is the only surviving member of this subfamily, but it’s nearest relatives existed as recently as 2 million years ago.
The panda’s closest ancestor was essentially a smaller version of today’s giant panda, being about half the size and still making its home in China.
That ancestor is thought to have evolved from a bear that didn’t even eat bamboo roughly 8-10 million years ago.
This distant ancestor lived in Europe and it wasn’t until the bear migrated to the Asian continent that the panda family’s teeth and jaws began to change to enable them to use bamboo as their primary food source.
Scientists haven’t documented every step in the giant panda’s evolution and there’s still lots of fossil evidence missing before a full picture can be established.
This unqiue evolutionary path is one of the things that has cast doubt on which animal family the panda belongs to. It’s been some time since the giant panda split off from the rest of the bear family!
What does the evidence say?
It’s not hard to spot what evidence there is in favour of the giant panda being considered a bear.
Most people feel the bear classification is about right based on the obvious physical and behavioural characteristics above.
The evidence that the panda might not be a bear is a little more complicated, so we’ve done our best to break it down here.
Four reasons the giant panda might not be a bear:
Genetic analysis: Genetic studies have revealed intriguing genetic distinctions between giant pandas and other bear species. While pandas share certain genetic similarities with bears, they also exhibit unique genetic markers that differentiate them from other bear species. This has prompted some scientists to propose alternative taxonomic groupings for the giant panda.
Dietary specialization: Unlike other bear species that exhibit a broad omnivorous diet, giant pandas have a highly specialized diet that consists almost exclusively of bamboo. Their digestive system and skull structure have adapted to handle the consumption of large quantities of bamboo. This dietary specialization sets them apart from other bear species that have a more varied diet.
Skull morphology: The skull structure of giant pandas shows some distinct features that differ from typical bear skulls. For example, pandas possess enlarged molars and a modified jaw structure that aids in their bamboo consumption. These unique characteristics have led some researchers to suggest that pandas represent a separate lineage or an evolutionary specialization within the bear family.
Fossil evidence: Fossil records provide insights into the evolutionary history and relationships among species. Some researchers argue that the fossil record of the giant panda indicates a more distant evolutionary lineage from other bear species, further supporting the idea of its unique taxonomic position.
The debate surrounding the giant panda’s classification is ongoing, and different scientists have different viewpoints.
While the current consensus classifies giant pandas within the bear family Ursidae, these alternative lines of evidence have prompted discussions about potential revisions to their taxonomic placement.
There’s so much for us still to learn about the giant panda and so much for this amazing animal to teach us about the animal kingdom.
What about the red panda?
Despite sharing a common name, giant pandas and red pandas are not closely related at all.
Red pandas are the only living member of a family called the Ailuridae and giant pandas belong to the bear family, Ursidae.
The similar name is thought to be to do with the two animals’ shared diet as red pandas also eat a lot of bamboo.
The Nepali word ‘ponya’ translates to ‘bamboo eater’ and is thought to be one of the root words of the giant panda and red panda’s names.
The main physical similarity between the giant panda and red panda is their unusual ‘false thumb’ – an extra digit thought to have evolved in both animals to help them manage their bamboo diets.
This is why some scientisits originally believed that both the red panda and giant panda shared a distant cousin that might be closer to a raccoon or weasel than a bear.
