At Uncommon Descent, Mung makes an assertion that other creationists have raised from time to time:
However, I don’t see why similarity in design necessarily implies common descent. If an architect designs two slightly dissimilar buildings one after the other, where is the common descent in this process? I am assuming that by common descent, one means that the species arose via a long sequence of sexual reproduction events acted upon by random variations.
As a software engineer, I know I don’t use any kind of sexual reproduction mechanism to derive one class of objects from another. Why could not the designers have a huge database of pre-designed genes to choose from and with which to create new species of animals and humans? And why would they need sexual reproduction to accomplish this? Beings that advanced could easily incubate newly designed species outside the womb, no?
The problem with Mung’s assertion – and with ID in general – is the assumption that biology looks like the product of human design. That assumption underlies all design arguments. Mung even voices that assumption – “If an architect designs…” and “As a software engineer, I know…” The problem is that such an assumption also oversimplifies human design as the same technique, the same premises, and the same approaches for all the various things we have – buildings, software, golf clubs, tanks, smartphones, etc. But these items do not come from the same design approaches – not even close. It’s one of the reasons we have specialists like architects, mechanical engineers, software developers, structural engineers, synthetic biologists, and so on. Designer buildings, for example, requires a very different concept of purpose and functionality and a whole different set of issues to address than designing a smartphone. While some of the design considerations may be similar across various fields, many use completely different design tools, concepts, functional constraints, and techniques wholly unique to the field.
As such, assertions like Mung’s above make no sense given the variety of organisms out there. Sure, a designer could have “a huge database of pre-designed genes to choose from and with which to create new species of animals and humans”, but if a designer had such tools at his or her disposal, the dissimilarity of organic forms makes little sense. Why? Because, if – as Mung assumes – the designer is ‘like an architect’, then organism design parameters would be based on the same, or at least very similar, functional and form limits. In other words, in architecture, styles are conserved and only vary slightly across schools of design, mostly because in architecture all designers are based on the need to protect occupants from elements. As new architects break with certain schools, designs, some aspects of design become more varied – such as building materials, size, interior configuration, and so on – but the overall architectural design parameter – protection for occupants – is still conserved. The animal kingdom does not show such conservation except at the genus level however. Why? Were there different designers for different genuses and phyla? Different schools of design at different earth ages? If not, why did styles change so drastically across many of the genuses, but not within them? That’s where the analogy to human design completely breaks down and where the assumption of a designer makes little sense.
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