Evolution Video
Evolution Video Final from ellie holtaway on Vimeo.
Transcript of Video
For hundreds of years, scientists have been trying to understand the evolutionary process that turned wolves into mans’ best friend. Scientists are still trying to pinpoint exactly when the domestication of the dog took place, and new research is making the answer become more clear.
Before we can look into the domestication of the dog, we must define what exactly it means to be domesticated. Most scientists define domestication by the defining behavior, anatomical, and physical changes in the species such as floppy ears, colored fur, change in tail length, changes in reproductive cycle, and decrease in behavioral traits such as aggression and timidness. In An Origin of Species, Charles Darwin points out no adult wild animals (except elephants) have floppy ears.
Dmitry Belyaev, a soviet biologist, was puzzled by the question of domestication, so, in 1959 he began an experiment that would later challenge all that scientists thought they knew about dog domestication.
Before Belyaev’s experiment, scientists believed that humans went to wolf dens and removed wolf pups at a very early age, so the pups would imprint on humans, for the purpose of hunting partners.
Belyaev began his experiment by forming a collection wild caught silver foxes. Then each fox was evaluated and given a tameness score. Only the tamest foxes were allowed to breed, in each generation. The results of selective breeding based on tameness were remarkable. In as few as eight generations, the foxes had completely transformed. They not only lost all aggression towards humans, but their coats began to vary in color and length. In a few more generations, the foxes displayed affection towards humans, they played with each other, and acted almost exactly like domestic dogs. They observed changes in reproductive seasons and in bone structure.
The results proved Belyaev’s theory: that selective breeding for tameness alone is the basis of domestication.
So how does this relate to the domestication of dogs? Well, the newest theory in the domestication of the dog is that Dogs evolved from a group of wolves that came into contact with a European hunting group during the between 18,800 and 32,000 years ago right when humans began formed settlements as opposed to being nomadic hunters.
Once humans came into the wolves natural hunting territory, there was a decline in prey animal population. This forced the wolves to scavenge human waste in order to survive. This lead to a sudden shift in the wolf behavior. Instead of being afraid of humans, the wolves that had the least amount of fear towards humans were able to get closer, therefore get more food. Then, because of natural selection, the wolves that showed less fear towards humans survived, while the timid wolves did not. So, wolves were selectively breed for lack of aggression towards people.
As shown by Belyaev’s fox experiment, breeding for lack of aggression would have lead to physical changes in the wolf. So, scientists now believe that effectively, dogs domesticated themselves. Since then, the selective breeding process has led to the wide variety of canines we see today.
For more information about the domestication of the dog, visit the following sources. Thank you for listening!
Before we can look into the domestication of the dog, we must define what exactly it means to be domesticated. Most scientists define domestication by the defining behavior, anatomical, and physical changes in the species such as floppy ears, colored fur, change in tail length, changes in reproductive cycle, and decrease in behavioral traits such as aggression and timidness. In An Origin of Species, Charles Darwin points out no adult wild animals (except elephants) have floppy ears.
Dmitry Belyaev, a soviet biologist, was puzzled by the question of domestication, so, in 1959 he began an experiment that would later challenge all that scientists thought they knew about dog domestication.
Before Belyaev’s experiment, scientists believed that humans went to wolf dens and removed wolf pups at a very early age, so the pups would imprint on humans, for the purpose of hunting partners.
Belyaev began his experiment by forming a collection wild caught silver foxes. Then each fox was evaluated and given a tameness score. Only the tamest foxes were allowed to breed, in each generation. The results of selective breeding based on tameness were remarkable. In as few as eight generations, the foxes had completely transformed. They not only lost all aggression towards humans, but their coats began to vary in color and length. In a few more generations, the foxes displayed affection towards humans, they played with each other, and acted almost exactly like domestic dogs. They observed changes in reproductive seasons and in bone structure.
The results proved Belyaev’s theory: that selective breeding for tameness alone is the basis of domestication.
So how does this relate to the domestication of dogs? Well, the newest theory in the domestication of the dog is that Dogs evolved from a group of wolves that came into contact with a European hunting group during the between 18,800 and 32,000 years ago right when humans began formed settlements as opposed to being nomadic hunters.
Once humans came into the wolves natural hunting territory, there was a decline in prey animal population. This forced the wolves to scavenge human waste in order to survive. This lead to a sudden shift in the wolf behavior. Instead of being afraid of humans, the wolves that had the least amount of fear towards humans were able to get closer, therefore get more food. Then, because of natural selection, the wolves that showed less fear towards humans survived, while the timid wolves did not. So, wolves were selectively breed for lack of aggression towards people.
As shown by Belyaev’s fox experiment, breeding for lack of aggression would have lead to physical changes in the wolf. So, scientists now believe that effectively, dogs domesticated themselves. Since then, the selective breeding process has led to the wide variety of canines we see today.
For more information about the domestication of the dog, visit the following sources. Thank you for listening!
Project Summary
The purpose of this project was to teach our peers about different aspects of evolution. Most of the class choose the option to make a video explaining the basis of evolution. I choose the last option, which was to create a video about any subject of evolution that you want. I choose to explain the evolutionary process that turned the wolf into the dog. After identifying my essential question, I began to research the subject. I watched documentaries, looked at reports, and read webpages. I gathered information from all of my sources and started to compile them in the form of notes. Then, I identified the main points that I want to include in my video. Next I organized the topics into a basic outline, and cut some topics that were not necessary to support my points. Then, I changed the outline into a complete script by expanding each point referencing my notes. After my script was complete, I read it out loud and timed it to make sure it fit the time requirements.