Joined: Jan. 2006
|Immune systems appeared relatively recently in the history of life. The innate immune system is presumed to date back about a billion years to bilaterians but more interestingly and more to your point the adaptive immune system appeared suddenly in jawed vertebrates about 450 million years ago.|
Given that life has been around for 3.5 billion years and adaptive immune systems to fight invasive pathogens appeared suddenly only half a billion years ago this does have the appearance of a post-design improvement. Sort of like putting a windscreen on a motorcycle to keep the bugs out of your face.
On your question about where bacteria came from… two answers. Maybe they were here all along but weren’t pathogenic. The second answer is based on the fact that it’s far easier to lose complexity than to gain it. What’s the easier path - for a bacteria to acquire a nucleus out of the blue or for a nucleated cell to lose its nucleus. Devolution is always the easier path. Of course this assumes a complex beginning but complex beginnings are the hallmark of intelligent design and around here we don’t presume intelligent design is out of the question.
*points and laughs*
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