Move over tech heads, there’s a new king on Route 128, and while he’s still a nerd, this time he’s hunched over a microscope, not a keyboard.

Drug giants and massive lab complexes have quietly overtaken software companies and missile makers as the largest single industry in the heart of the Route 128 corridor, according to a Richards Barry Joyce & Partners report.

It’s the end of an era, no doubt, punctuated by the sad passing last week of Digital Equipment co-founder Kenneth Olsen. And it’s quite a shift for a corridor that proclaimed itself “America’s Technology Highway” – replete with fancy roadside signs – back in the 1980s.

But it’s more than that.

As we climb out of this recession, we had better figure out fast where to place our bets, and biotech, not high tech, is where it’s at right now for Greater Boston.

“Throughout the economic downturn, the biotech sector outperformed what we saw in the tech sector,” said Brendon Carroll, research chief for Richards Barry Joyce & Partners.

The shift so far has been relatively unheralded, though plain to see.

Susan Windham-Bannister, chief executive of the Massachusetts Life Sciences Center, can see the changes from her office window in Waltham – right off 128 of course – with Astra Zeneca just across the highway. For its part, AstraZeneca did set up shop along 128 in Waltham a decade ago.

“The Route 128 corridor is a perfect location for them,” she said. “You have seen the signage for the tech companies giving way to the signage for the life sciences companies.”

Taking The Lead

Blame the Great Recession, if you want. As tech companies, along with everyone else, cut back and reined in expenses, drug giants and life sciences firms just kept on growing.

The score: 17 percent of the Central 128 corridor, stretching from Dedham to Burlington, is now occupied by biotech and life sciences firms, compared to 14 percent for software companies, according to RBJ.

Rounding out the pack, health services trails at third, with 10.4 percent of the market, and consulting at a distant 9th, tallying roughly 7 percent.

The changing of the guard can be seen quite vividly along the Lexington stretch of the highway.

Shire Pharmaceuticals is rolling out a big campus in town, and is right now adding hundreds of thousands of square feet. And the location of this expansion could not be more fitting – the site of Raytheon Co.’s former world headquarters.

Shire unveiled plans in 2008 for a nearly $400 million expansion in Lexington which would double its local workforce and include a move of its headquarters from Cambridge. Over the summer, Shire bought more than a dozen additional acres to tee up for still further expansion.

Another shift can be seen in Burlington, which for years has been the proud home of Sun Microsystems, which through the 1990s had a seemingly insatiable appetite for land and new buildings.

But as the computing company’s fortunes have turned downward, Burlington has gone on the hunt for biotechs, rezoning millions of square feet for lab and research complexes.

All told, the Central Route 128 corridor now accounts for nearly half of all the biotech space in Boston’s suburbs. Add in Framingham and Natick – both corporate powerhouses in their own right, though just outside the traditional 128 corridor – and that number rises to almost 70 percent.

There are other signs as well, so to speak.

The West Waltham Suburban Chamber of Commerce, which represents companies along this stretch, is now led in part by a top drug company executive, AstraZeneca’s John Hennessy, who oversees the firm’s Boston area research and development operations. At the chamber, he is vice chair.

Down, Not Out

Of course, it’s too early to write off the tech sector. Shaking off the recession blues, some of the industry’s big players are on the march again, with Google hiring at its big Cambridge pad and Microsoft gobbling up extra office space as well.

And of course there is French software maker Dassault Systèmes, which is preparing to move into 325,000 square feet along 128 in Waltham.

Still, the innovation torch has been passed.

Greater Boston has increasingly lost its role at the cutting edge of the tech industry since Digital was acquired in the early 1990s. Sure, lots of tech companies have set up shop here, but Route 128 and Cambridge have become glorified colonies of California’s Silicon Valley.

Not so with biotech, where we retain the cutting edge. How to keep that blade sharp is another question, with the Patrick Administration eager to throw money at the sector like a drunken sailor.

All that effort might be better spent leveling the playing field for all businesses and tackling some of the many disincentives for expanding here, from loony housing and health costs to mindboggling red tape.

After all, drug companies are in the same bind as everyone else when they try and recruit talent from other states, only to have a prospective star hire balk after looking at local home prices.

Money is one thing, but maybe it’s also time to show a little overdue respect for the new top dog along Route 128.

So let’s pull those old America’s Technology Highway signs out of whatever state highway department bunker where they were stashed, spiff them up, and roll them out with a message fit for our brave new era.

“America’s Biotech Highway” anyone?