Eastman Kodak (NYSE: EK) is apparently standing near the corporate equivalent of death's doorstep. It recently hired Jones Day, a law firm that specializes in restructuring, leading to speculation that the storied photography giant may itself file for bankruptcy.

It's an unfortunate endgame for a company that was destroyed in large part by the digital photography revolution it actually pioneered. But it also serves as a harsh reminder that the rule of the corporate jungle remains "adapt or die."

What once was
Kodak was no slouch of a company. It has a longer than 130-year history, and it was an American exporter as far back as 1889. At one time it was so formidable, well-known, and respected, that it was a member of the Dow Jones Industrial Average (INDEX: ^DJI) , an elite group of companies whose shares are often used as a proxy for the health of the overall economy.

Yet today, the photography giant is "exploring strategic alternatives" and could declare that rumored bankruptcy, should its other alternatives (like a breakup or a sale of its patent portfolio) fail.

Kodak isn't alone
The Kodak story, while tragic, isn't unique among even the companies that make up the Dow Industrials. In fact, of the original 12 stocks in that index, only General Electric (NYSE: GE) remains there today, and even that giant stumbled hard during the recent financial meltdown. Other recent spectacular crashes among the Dow titans include General Motors (NYSE: GM), whose own 2009 bankruptcy got it kicked out of the index.

Indeed, if anything, the "adapt or die" rule may actually be accelerating in today's digital and global era.

It wasn't that long ago that Sun Microsystems was at the forefront of the Internet. Nearly 70% of the early Internet applications were written on its hardware, an amazingly high market share. Yet today, after several years of stumbling on its own, Sun survives only as part of Oracle (Nasdaq: ORCL), following a 2010 acquisition.

And let's not forget that today's giant of the Internet, search king Google (Nasdaq: GOOG), was itself a "Johnny come lately", founded in 1998. That was three years after its former competitor AltaVista got off the ground, nearly an eternity in "Internet years." Yet today, AltaVista searches are likely actually powered by Microsoft's (Nasdaq: MSFT) Bing, an ironic fate for that Internet pioneer.

Speaking of Google and Microsoft, that particular war isn't anywhere near settled. Bing, after all, is essentially Microsoft's attempt to fight Google on Google's home turf of search. And Google isn't playing purely defense either, choosing to go after Microsoft's Office and Windows franchises with its Docs and Chromebooks, respectively.

There may very well be room on the Internet for both companies. That said, the one thing that'll likely come true is that if one of them rests on its laurels, that will be the one that falls farthest and fastest.

What this means to investors
Whether it was Kodak inventing digital photography, Sun's early pioneering on the Internet, or AltaVista's search engine, just because you have the lead today doesn't mean you'll have it tomorrow. Any company that wants to last needs to innovate just to maintain its current position, much less continue to grow its business over time.

As an investor, it means that you must remain ever vigilant with the companies you own, always on the watch for what might come around to disrupt your company's operations. When (not if) that disruption happens, watching how your company responds will speak volumes for its long-term staying power and worthiness to remain in your portfolio.

Disruptive change will happen. The companies that successfully adapt may very well come out stronger, but the ones that don't will almost certainly die. That's even true of companies like Kodak that were once so well-known and respected to appear in the Dow Jones Industrial Average.