State how comparing the amino acid sequence of a protein can provide evident that evolution has taken place.
A: If evolution has taken place, then, in general, species descended from a recent common ancestor should have fewer amino acid differences between their proteins than do species that share a common ancestor in the more distant past.
To compare the amino acid sequence of a protein, you need to follow a few steps:
1. Identify the protein: Choose a specific protein that you want to compare across different species. This protein should be present in all species you want to analyze.
2. Obtain the amino acid sequences: Collect the amino acid sequences of the chosen protein from different species. These sequences can be found in scientific databases or obtained through experimental techniques like DNA sequencing.
3. Align the sequences: Use bioinformatics tools or software to align the amino acid sequences. Sequence alignment allows you to identify the positions where the amino acids in different species are similar or different.
4. Analyze the differences: Once the sequences are aligned, compare the amino acids at each position. Count the number of differences between species and calculate the percentage of amino acids that differ.
Now, let's see how comparing the amino acid sequence of a protein can provide evidence for evolution:
If evolution has occurred, species that share a recent common ancestor should have fewer amino acid differences between their proteins compared to species that share a common ancestor in the more distant past. This is because over time, genetic mutations accumulate in the DNA sequences, including the gene that codes for the protein.
If two species have similar amino acid sequences in the protein being compared, it suggests that they share a more recent common ancestor as there has been less time for mutations to accumulate. However, if two species have significantly different amino acid sequences, it indicates that they diverged from a common ancestor in the more distant past and have accumulated more mutations over time.
By comparing the amino acid sequences of a protein across different species, scientists can study the relatedness of species and construct evolutionary relationships. This method provides valuable evidence supporting the concept of evolution and the idea that species have descended from a common ancestor.