Science Buddies: "Ask an Expert"

Hello Sir/Madam
I was doing a project similar to the primate line project on this page which allows you to find the rate of mutation. I have used the protein cytochrome c and cytochrome c oxidase from the homo sapiens genome and ran in on the BLAST software to identify the identify percentage in primates. I have been stuck on trying to identify the rate of mutation with the data that i collected.
Another calculation that i have which im not sure is relevant is the average mtDNA mutation rate x base pair which would = no.of mutations/bp/20 generation which im not sure what it means.
Im really confused on how to calculate the mutation rate in primates with the data i have collected. i have 5 primates and their data for the % similarity between collected but i do not know how to go from there.

The results i got for cytochrome c protein were:
1. chimp - 100%
2. gorilla - 100%
3. orangutan - 100%
4. colobus - 99%
5 - lemur - 91 %

if i were to take the percentage difference and divide it by the millions of years to find the average mutation rate
the answer i get is 3.96825 x 10^-8 which is incredibly small. since id get 0 for the first 3 primates i did 1/6000000 + 9/63000000, added them then divided by 5. - im not sure if this is the right way to do this?
i have the same problem with cytochrome c oxidase however as the percentages are:
1. chimp - 99
2. gorilla - 98%
3. orangutan - 99%
4. colobus - 95%
5 - lemur - 89 %

https://www.sciencebuddies.org/science- ... #procedure

this is the project i was using but with proteins cytochrome c and cytochrome c oxidase.

Thank You,

Brindha

Hi Brindha,

You are correct in that the rate of mutation for the chimp, gorilla, and orangutan is 0 for cytochrome c. If you're trying to have different mutations for all of them, you might not be using the right protein to show the differences...you could try using the suggested NP_536853 and see if the percentages align with the times at which the species split off. If you want to calculate the rate of base pair mutation, you would do (% difference as a decimal)*(total number of base pairs in the gene)/(millions of years since the species split off) to get number of base pairs mutated/millions of years. I hope this helps!

Elena