Some of the first comments submitted in this thread suggest to me that it may be helpful to review the various convergent lines of evidence for macroevolution,

Some of the first comments submitted in this thread suggest to me that it may be helpful to review the various convergent lines of evidence for macroevolution, which along the way will help explain how biological evolution works and why very old "complexity" is not a surprise in the fossil record. (One problem is defining "complexity" adequately in this context.) See the very informative collaboratively edited website 29+ Evidences for Macroevolution: The Scientific Case for Common Descent[1] for the broad overview, and specifically the sections responding to "complexity"[2][3] for more details on that issue. [1] http://www.talkorigins.org/faqs/comdesc/ http://www.talkorigins.org/faqs/comdesc/ [2] http://www.talkorigins.org/indexcc/CI/CI101.html http://www.talkorigins.org/indexcc/CI/CI101.html [3] http://www.talkorigins.org/faqs/behe.html http://www.talkorigins.org/faqs/behe.html