In: Biology
Similar genes (homologs) are found in humans. Do you expect the expression of these genes to be similar during human development? During cancer development?
All organisms share different degree of genes homology and this is one of basis in the evolution and currently being employed and analyzed by molecular taxonomist. If you compare non-visible bacterial cell with human, then you will be surprised; we share great homology with bacterial cells as well. Tiny insect share up to 70% gene homology, mammalian animals like rat and mice share 95% gene homology, primates and modern apes are having more than 99% gene homology and its absolute in case of identical twins. Several genes are similar with minute difference and same function is performed by same genes, for example superoxide dismutase is encode by two genes in human sod2 and sod2 and only their expression zones are different.
If we take an example of development, Hox genes are not only similar in human but it is also important in vertebrates and invertebrates, similarly hedgehog genes. For the cancer development, humans are having guardian gene known as p53 and it is also present in other animals including several dozen copies of this gene in elephants. Similarly genes for neurological disorder is also homologous in human as compared to others.