Crossing over at prophase I results in the linked genes (those on the same chromosome) becoming unlinked and separated. Prophase I is this first stage of meiosis, the chromosomes condense, form tetrads<span>, and exchange DNA. The nucleolus and nuclear envelope disappear.</span>
The statement we could make about the four species based on the phylogenetic or evolutionary tree would be that they all originate from one gene pool or source. As evolution expands, one animal or species develops many different accommodations to their geneology based on environmental factors. Over a span of thousands of years, these changes can lead to an entirely new species.
The various enzyme in our body are : Proteins.
