Jean-Baptiste Lamarck was the 19th century natural philosopher who is now best known for his much derided theory of evolution.
Lamarck postulated that animals acquire characteristics through their experiences and, importantly, these characteristics can be passed onto their offspring. The archetypical example is that the giraffe developed such a long neck through successive generations of animals extending their necks to get to the tender leaves on the higher branches of trees. Each generation saw the necks get a little bit longer as the animals continued to stretch out. The efforts of one generation were manifested in the next, the offspring benefited from what their parents had attempted.
Lamerck's theory - this inheritance of acquired characteristics is now widely refuted (including through experiments that had the tails of mice cut off for generations and yet they continued to be present on babies). Darwin's theory of natural selection is now accepted as the true driver of evolution.
.NET Passport is Microsoft's now much derided web-based identity management scheme that never really reached the potential that Microsoft seemed to imagine for it. .NET Passport spent its life in an environment of mistrust (e.g. why would I share my credit card with Microsoft) and privacy concerns (e.g. no one provider, even/especially Microsoft should have alll a user's identity info). While the SSO aspect of .NET Passport was apparently very successful amongst other Microsoft sites (e.g. MSN), other aspects (like the wallet) were not taken advantage of.
Like a giraffe's neck being lengthened through the exercises of its ancestors reaching for sweet acacia leaves, or like a mole rat losing its vision through successive generations of living in the dark, Microsoft is positioning .NET Passport's offspring as benefiting from the experiences of its ancestor. We have learned! What wasn't used is gone! We are now in context!
Lamarck would love it. Darwin not so much.
Strictly speaking, this would appear to be an example of the Baldwin Effect rather than a true Lamarckism.