"Android is like Europe," Apple (NASDAQ:AAPL) CEO Tim Cook told The Wall Street Journal back in February. He continued:

Europe was a name that somebody came up with for Americans who didn't understand that Europe was a lot of countries that weren't like U.S. states. They were very different. Android is many things.

Indeed. Google's (NASDAQ:GOOG) mobile operating system is known for its fragmentation, powering hundreds of different handsets with dozens of different screen resolutions. Google updates the Android operating system annually, but new versions take years to catch on -- as of February, one out of every five Android devices still ran Gingerbread, a three-year-old version of the operating system.

That fragmentation helps to explain why, despite dominating in market share, Apple's iOS receives preferential developer treatment (Dave Feldman, writing for TechCrunch, recently explained that his start-up abandoned Android because of its fragmentation.)

That fragmentation is about to increase significantly. As Apple and Google push into wearable technology, the gap between the relative unification of their mobile ecosystems appears destined to intensify.

Some of Google's hardware partners aren't backing Android Wear
In time, it seems wearable computing devices will encompass a great variety of gadgets, from smart earbuds to digital glasses, but for the time being, the wrist seems to have emerged as the first great battleground.

Two of Google's largest hardware partners -- Samsung and Sony -- have already entered the market. So far, Sony has released two smartwatches, while Samsung has released three and a fitness tracker hybrid. Sony's watches run a slightly customized version of Android, as does Samsung's original Galaxy Gear. But the Gear's successors -- the Gear 2 and the Gear 2 Neo -- run Tizen, Samsung's own operating system, and the Gear Fit is completely proprietary.

To put it another way, none of these devices is powered by Android Wear, Google's official smartwatch solution. To be fair, there was no way they could've been -- these devices were conceived long before Google launched Android Wear -- but with their own smartwatch platforms now established, both companies look set to continue emphasizing their alternative solutions.

Sony, in response to Android Wear, said that will remain focused on its own smartwatch platform. Samsung is said to be on board with Android Wear, but is far more incentivized to support the Tizen-powered Gear. Since Gear owners are unable to use their watches with non-Samsung-made smartphones, they are more or less forced to purchase Samsung's handsets.

Apple's iWatch could reinforce its biggest advantage
Apple hasn't unveiled its smartwatch, but when it does, it seems certain to be a heavily integrated product. Recent reports suggest that Apple will ship the iWatch in two different sizes and may even offer a luxury version with a $1,000+ price tag. But if recent rumors are any indication, they will all run the same modified version of iOS -- an operating system Apple has been unwilling to license.

When it comes to mobile software development, that could reinforce Apple's advantage: Developers looking to extend their mobile apps to the wrist wouldn't need to worry about a broad set of devices running a wildly different set of operating systems. Android development, in contrast, could get even more hectic -- some Android handset owners could be sporting Google's official Android Wear solutions, others might have a Tizen-powered device, and still others might be using Sony's smartwatch or something else entirely.

That fragmentation has its advantages -- a wide variety of choices being the most obvious. But with Google's Android still lagging iOS in terms of developer support, the coming smartwatch revolution has the potential to extend Apple's lead even further.