How does the development of an embryo provide clues to the evolution of present day organisms?

How can a geological time scale best be reconstructed? a) comparing vestigial structures in living species b) comparing homologous structures in living species c) examining homologous structures in fossil remains d) examining the written records of scientists from past cultures

In general, characteristics that an organism survive and reproduce become more common in a population over time. what mechanism of evolution cause this change?

The big bang theory suggest that the universe is about - 300 million years old - 4.6 billion years old - 30 billion years old - 13 billion years old