Search results
Results from the WOW.Com Content Network
In biology, homology is similarity in anatomical structures or genes between organisms of different taxa due to shared ancestry, regardless of current functional differences. Evolutionary biology explains homologous structures as retained heredity from a common ancestor after having been subjected to adaptive modifications for different ...
It is the site of attachment of the future prepuce. Just anterior to the anal tubercle, the caudal end of the left and right urethral folds fuse to form the urethral raphe. The lateral part of the genital tubercle (called the lateral tubercle) grows longitudinally and is about the same length in either sex.
Comparative anatomy is the study of similarities and differences in the anatomy of different species. It is closely related to evolutionary biology and phylogeny [ 1 ] (the evolution of species). The science began in the classical era , continuing in the early modern period with work by Pierre Belon who noted the similarities of the skeletons ...
Homology (psychology), behavioral characteristics that have common origins in either evolution or development Homologous behaviors , behaviors typical of species that share a common ancestor that was characterized by that behavior OR behaviors in an individual that share common origins in development
The pattern of limb bones called pentadactyl limb is an example of homologous structures (Fig. 2e). It is found in all classes of tetrapods ( i.e. from amphibians to mammals ). It can even be traced back to the fins of certain fossil fishes from which the first amphibians evolved such as tiktaalik .
This involves that the term "percent homology" is a misnomer. [4] As with morphological and anatomical structures, sequence similarity might occur because of convergent evolution, or, as with shorter sequences, by chance, meaning that they are not homologous. Homologous sequence regions are also called conserved.
Whereas ordinary homology is seen in the pattern of structures such as limb bones of mammals that are evidently related, deep homology can apply to groups of animals that have quite dissimilar anatomy: vertebrates (with endoskeletons made of bone and cartilage) and arthropods (with exoskeletons made of chitin) nevertheless have limbs that are constructed using similar recipes or "algorithms".
This is different from homology, which is the term used to characterize the similarity of features that can be parsimoniously explained by common ancestry. [1] Homoplasy can arise from both similar selection pressures acting on adapting species, and the effects of genetic drift. [2] [3]