Phylogenetics, or the study of the relationships between organisms, is now almost entirely done based on genetic sequences. This requires, of course, a gene common to all organisms, and one of the first universal trees of life derived from genetic information used the small subunit ribosomal RNA (ssrRNA) to show that the last universal common ancestor (LUCA) existed somewhere at the origin of bacteria and archea, with the eukaryotes (which includes all animals) branching off of the archea later in time.
Apart from phylogenetics, however, the universality of the genetic code, the prevalence of L-stereoisomers of amino acids and the ubiquity of adenosine in biochemical processes all suggest either a common ancestor or a group of very similar ancestors as the origin to all modern life.
what is Similar structures that related species have inherited from a common ancestor
Homologous structures.
Homologous structures!
Homologous structures!
Homologous structures.
ancestor
DNA sequences
what is Similar structures that related species have inherited from a common ancestor
Some structures that related species have inherited from a common ancestor are homologous structures, which are similar in form and function but may have different appearances due to adaptations to different environments. Another example is vestigial structures, which are remnants of structures that were functional in ancestral species but have reduced or lost their original function in descendants. Analogous structures are also seen in related species, having similar functions but different origins, such as the wings of birds and insects.
Homologous structures.
Homologous structures are structures that are similar in related organisms because they were inherited from a common ancestor. These structures may or may not have the same function in the descendants. Figure below shows the hands of several different mammals. They all have the same basic pattern of bones. hope it helped
Why do scientists think related species have similar body structures and development patterns?