Dogs and Evolution
This is Goal 3, Part 2.
This is a flyer over the evoultion of dogs over time using fossil records, morphology, DNA analysis, and artificial selection.
Fossil Records
Fossils records that show how dogs have changed over time from fossils. Such as this one found in 1970 in Siberia. This fossils shows that when the first humans came on earth, the wolves were a very large and ridged animal. (1) Soon, wolves began to bond with the humans. As time went by and dogs became more comfortable with humans, the wolf then became smaller, had wider skulls, and had offspring that were smaller than wolves. Eventually dogs became as what they are know today, also with artificial selection from humans breeding them.
Source:
Morphology
The morphology of a dog is consisted of its ear, nape, neck, withers, back, hip, rump, buttock, tail, thigh, leg, hock, cannon bone, hind leg, belly, hind leg, wrist, fore leg, breast, shoulder cheek, mouth, tip of nose, nose, eye, for head. All of these traits are similar the wolf which is the dog's main ancestor.
Sources:
http://visual.merriam-webster.com/animal-kingdom/carnivorous-mammals/dog/skeleton-dog.php
DNA Analysis
DNA Analysis in dogs is present from mitochondrial DNA sequences from ancient dogs remains showed that ancient dogs came from many parts of the world. Geographic isolation isolation with geographic barriers, also played a world in the evolution of dogs before they became domesticated. The ancient dog had a clade, but it was absent due to the face that most of the dogs today have been breeded so much from the ancient dog. The clade so far is only the dog and the wolf, but the dog has changed into many different breeds across continents.
Source:
Artificial Selection
Artificial Selection in dogs is very real in todays world as humans breed dogs in order to make different breeds of dogs. The breeders who breeded dogs told darwin that the traits that were breeded from dogs usally passed on to its next generation. From breeders, when breeding dogs with certain traits for a specific purpose, the ones that are best breed for thier traits survive the best. For example, in the cold, a breeder who breeds a dog that has large amounts of dense black fur will survive the best than a dog breeded with no fur and is white.
Source:
http://www.windows2universe.org/cool_stuff/tour_evolution_7.html
Habitat and Adaptations.
Sources:
(1) http://wiki.answers.com/Q/What_is_the_habitat_of_the_wolf
(2)http://wiki.answers.com/Q/What_adaptations_do_dogs_have_that_keep_them_cool_in_hot_weather
(3)http://wiki.answers.com/Q/What_do_dogs_eat
(4)http://answers.yahoo.com/question/index?qid=20070529060640AAHm3Ve