The functioning of proteins and genes in various organisms is $.....P.....$ which indicates that they share a $.....Q.....$ ancestor.

Define homologous organs,recapitulation theory,and fossils.

In the developmental history of the mammalian heart,it is observed that it passes through a two-chambered fish-like heart,a three-chambered frog-like heart,and finally a four-chambered stage. To which hypothesis can this above-cited statement be approximated?

The conclusion that 'life forms on Earth not only resemble each other but also resemble life forms that lived millions of years ago' is based on the observations of whom?

Define/Explain the following terms:
$(1)$ Paleontology
$(2)$ Acquired traits

The study of homologous structures in mature organisms provides evidence for the evolutionary relationships among certain groups of organisms. Which field of study includes this evidence of evolution?