The biological species concept defines a species as members of populations that actually or potentially interbreed in nature, not according to similarity of appearance. It explains why the members of a species resemble one another and differ from other species. When two organisms breed within a species, their genes pass into their combined offspring. As this process is repeated, the genes of different organisms are constantly shuffled around the species gene pool. The shared gene pool gives the species its identity. By contrast, genes are not (by definition) transferred to other species, and different species therefore take on a different appearance. It’s not surprising that some species can interbreed with one another because according to the biological species concept two different and isolated animals like dogs and wolf can interbreed because they were part of the same species. They became 2 different species because of variations and the genetic changes that have occurred within the species. They share many similarities, they both have 78 chromosomes and are part of the same genus, Canis. The geographical and behavioral isolation created by the humans by domesticated the dogs have made them diverged from one another. It became complicated for them to interbreed but without the isolations and boundaries they would interbreed due to the fact that dogs are descended from wolfs, therefore they are the same species. Paleospecies is species defined from fossil evidence, often covering a long-time span. Because the task of interpreting paleospecies is so difficult, paleoanthropologist have sought various solutions. Most researchers today define species using clusters of derived traits. (Essentials of Physical Anthropology, p107). In the case of dogs and wolf, if they were extinct species and all we had were fossils remains, I think that they we would identify them as the same species because of the many similarities they share. genetic evidence, have shown that dogs are descended from wolf. Both dogs and wolves share behaviors, physical attributes, social interaction, territorial instincts and forms of communication and they have the same number of chromosomes which I think is sufficient to identify them as one species.