The past 10 years have seen Big Pharma repeatedly cannibalize itself via megamerger, trimming its ranks through waves of layoffs and a dogged pursuit of efficiency. But Big Biotech, the emerging middle class of not-quite giants, has more than made up for those cuts, essentially doubling to add more than 130,000 workers since 2003, according to EvaluatePharma.

In a new report charting employment trends over the past decade, EvaluatePharma highlights something of a great migration. Since 2003, the world's largest drugmakers have reduced their headcounts by about 3%, but just below the Big Pharma threshold, among companies with market caps of at least $30 billion, payrolls are swelling.

Biotech luminaries Celgene ($CELG), Regeneron ($REGN) and Gilead Sciences ($GILD) have more than tripled their individual staffs over the past decade, according to EvaluatePharma, and unlike Big Pharma, Big Biotech has taken a more organic approach to growth. Most of the M&A among the industry's middle tier has focused on asset-driven buyouts of research-stage companies, not huge takeouts of vertically integrated giants, and the burgeoning employment numbers at Amgen ($AMGN), Biogen Idec ($BIIB) and Allergan ($AGN) are largely due to organic gains, according to EvaluatePharma.

And, looking at just the last 5 years, a new crop of emerging biotechs seems poised to keep up the trend. By percentage of staff added, the biggest hirers since 2008 include Questcor Pharmaceuticals ($QCOR), soon to fall under Mallinckrodt ($MNK) for $5.6 billion; Pharmacyclics ($PCYC), which has upped its staff nearly 10-fold on the way to FDA approval for an expected blockbuster; and Alexion ($ALXN), maker of the world's most expensive drug.

Unsurprisingly, a look at Big Pharma tells the opposite story. The colossal deals that whittled Wyeth into Pfizer ($PFE) and trimmed Schering-Plough into a Merck ($MRK)-sized box resulted in thousands of layoffs, largely among sales reps. But an unforgiving patent cliff and industry-wide problems with R&D productivity have led to cuts in the lab, too, headlined by GlaxoSmithKline ($GSK) and Sanofi ($SNY), companies that cut more than 6,000 research jobs over the last 5 years, EvaluatePharma notes.

But, as is illustrated by the continued growth of Big Biotech--and the rapid rise of global CROs--those many deposed scientists are not without employment opportunities.

- check out the report