Complexity of Life
The remarkable complexity of life, particularly at a cellular level, poses questions about the incremental changes proposed by evolution, challenging the notion that simple organisms can evolve into more complex forms without intelligent design.
Irreducible Complexity
Irreducible complexity suggests some biological systems, like the bacterial flagellum, are too complex to have evolved from simpler predecessors, as their functionality requires multiple parts present simultaneously, not developed sequentially.
Cambrian Explosion Puzzle
The Cambrian Explosion refers to the sudden appearance of most major animal phyla in the fossil record. This rapid diversification, occurring over 10 million years, challenges the gradualism central to Darwinian evolution.
DNA Sequence Constraints
The improbability of random mutations leading to viable DNA sequences is a puzzle. Given the vast number of possible combinations, finding a functional sequence by chance is extraordinarily unlikely.
Limits of Natural Selection
Natural selection may not account for the rise of novel traits, particularly when these traits offer no immediate survival advantage. It struggles to explain the foresight needed for complex trait development.
Molecular Machines
Cells contain 'molecular machines'—complex structures performing specific functions. Their intricate design and interdependent components challenge the idea that they could result from stepwise, evolutionary processes.
Genetic Information Source
The origin of genetic information is a major question. The encoding of information into DNA presupposes a source of information beyond mere chemical processes, posing a conundrum for the undirected process of evolution.