Video Transcript: -
Here is one simple piece of evidence which supports the theory of evolution. Protein sequence is produced through the translation of a non-lapping degenerate triplet code.
All code for alanine = GCA, GCT, GCG, GCC
All code for proline = CCA, CCT, CCG, CCC
So these 2 mutations will not effect the protein. And therefore have no effect on the organism.
But there's a complication. Condon bias can effect the rate of translation and therefore have an impact on fitness.
So these mutations are not as neutral as we thought. In humans though, one amino acid is special. Glutamic acid coded by GAA and GAG shows no bias. Therefore switching the codons has no effect on fitness.
So where does all this get us?
The theory of evolution makes a simple prediction. Since mutations occur at a low rate, closely related species should use the same condons for glutamic acid simply because there has not been enough time for divergence.
Intelligent Design/ Creationism make no prediction and therefore not testable and are not science.
So what do we find?
We are going to look at condons for glutamic acid in the alpha and beta chains of hemoglobin. We are going to compare 3 closely related species. 1. human 2. chimp 3. rhesus monkey
In both the hemoglobin alpha and beta chains ALL THE CONDONS MATCH.
Twelve of twelve positions use exactly the same codon in two species closely related to us. The probability of that occuring by chance is 1: 16, 777, 216.
But it didn't occur by chance. Evolution predicts this result. (Since mutations occur at a low rate, closely related species should use the same condons for glutamic acid simply because there has not been enough time for divergence.)
And that is only 2 of the 30,000 genes in our genome. And we only compared 3 species. This is only one of millions of pieces of evidence that supports the theory of evolution. Think about it.
For further information on evolution see:
evolution , natural selection , biology , genetics , intelligent design , creationism , greenday , green day