1 As you scroll through the protein and DNA sequence comparisons, you notice that they are organized from most similar to least similar. One hundred species are displayed for comparison. By the second species, small changes in the protein can be seen. These changes seem inconsequential and are only off by one or two amino acids. A quarter of the way through the results, the gaps and changes become exceedingly noticeable. Most E. coli strains are clumped near the top of the results page. This indicates that the E. coli protein is most similar to its close relatives and lease similar to its distant relatives. 2 The protein does not diverge at the same rate across its entire sequence. In some species, the gaps or changes will be near the beginning or end, and in other species, the gaps or changes are in the middle. Proteins that are closely related, two strains of E. coli for example, have highly conserved regions of the sequence and small portions of divergence. These closely-related strains probably embody a range of related
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