B.9A Evidence of Common Ancestry on level – 05

Using the chart above, the number of differences in the amino acid sequences from Human Cytochrome-c

Organisms that are closely related have fewer differences in amino acid sequences. The chart shows that the Human and the Monkey have the fewest differences in their amino acid sequences for Cytochrome-c. Therefore, these two animals are most closely related to one another and share a recent common ancestor.
Developmental Homology
In developmental homology, embryos of different species are compared to one another to find similarities in the stages of development. Many organisms look very similar as embryos. In the early stages of development, it is very hard to tell the different organisms apart.

All vertebrate embryos have a tail. In humans, only the tail bone remains in the fully developed person.
Molecular Homology
Molecular homology is the similarities in the genome of different organisms.
A genome is an organisms complete set of genes. Scientists can compare genomes of different organisms to see how similar or different they are from each other. Any time there is a change in the gene sequence of an organism, those changes are passed on to the offspring. By looking at the changes in the gene sequence between organisms, scientists can determine how closely or distantly those organisms are related to a common ancestor.