Hey Folks!
Welcome to my first official blogpost. Today I'll talk about something everyone can relate to in the world of coevolution, and that's dogs! Human's best friend wasn't always in our backyards and on our couches, they may have actually coevolved with us. You definitely wouldn't find a pack of wild pugs somewhere in the forest, so how did our furry friends come to be? Where did they come from?
As you might have gathered, humans didn't suddenly find an island of dogs and form a magical partnership in the ancient past. Dogs actually descended from wolves, particularly European wolves (Thalmann et al 2013). It was generally thought that the domestication of dogs occurred 11,000 to 16,000 years ago, but more recent DNA evidence using fossils suggests that domestic dogs could've had multiple origins, and could've been domesticated as far back as 135,000 years ago (Vilá et al 1997). Whether its tens of thousands or hundreds of thousands of years, we've been hanging around dogs a very long time, and there is evidence that we have, and continue, to coevolve with our beloved companions.
Schleidt & Shalter (2003) suggest an alternative hypothesis to the popular belief that we domesticated wolves after the agricultural evolution. They state that the canids used to follow herds of ungulates and feed on the weak, old, and sick individuals. At this time, early humans were hunters and gathers, and adapted to life on the savanna. Schliedt & Shalter claim that at this time, some early humans adopted the lifestyle of the canids, following herding animals for food. They joined the wolves as mutual predators. Early humans and canids, therefore, would have had their first contact as mutual predators, and coevolved together from that point, to eventually become loyal servants and friends of our modern human race. As human skill diversified, the ways in which dogs aided us did as well, from herding creatures to seeing eye dogs.
Additionally, humans and dogs may have similarly evolved genetically as we faced the same ecological pressures together. After sequencing the genomes of several dogs and wolves, researchers found that certain genes may have indeed evolved parallel to each other over time (Wang et al 2013). this is known as convergent evolution. Genes that were under positive selection pressure at the time for canines were the same as some that were positively selected for in humans. Genes involved in processes like metabolism, serotonin levels, and even cancer were evolving parallel between our 2 species. Wang and his team think that both species may have been evolving in response to a pressure in their environment such as overcrowding. The genetic change in serotonin levels may be associated with the need for less aggression to live in a crowded environment. This study suggests that studying dogs might shed light on human evolution as well as human disease and neurological disorders.
But really, are we all that surprised by this? We always knew our pups were special. They are always great listeners & understand us like nothing else. No seriously, there is science behind that! In a study done in 2001, dogs were tested on the ability to pick up social cues of humans, and dogs were better than chimpanzees! They have the same ability as a small child to pick up on communications like gazing, head nodding, and pointing (Soproni et al 2001). This could be because dogs have learned to pick up on human signals over time, because it can benefit them. For example, when you drop a piece of food on the floor and are to lazy to clean it up, your best friend will be your living vacuum at the point of a finger! Mutual benefits for both parties.
No matter how long we guess we've been connected or whether we evolved together by convergent evolution or coevolution, we already knew that our pups hold a special place in our hearts and minds. Go home and give your pooch a pat for dealing with us all these years, and a treat to thank them for choosing us.
Here's a bonus picture of me and my pup, just to show off how lucky I am :)
Enjoy your weekend, and I would love feedback on my first post!
Thanks for stopping by,
D
References:
Schleidt, W. M., & Shalter, M. D. (2003). Co-evolution of humans and canids. Evol. Cogn, 9, 57-72.
Soproni, K., Miklósi, Á., Topál, J., & Csányi, V. (2001). Comprehension of human communicative signs in pet dogs (Canis familiaris). Journal of Comparative Psychology, 115(2), 122.
Thalmann, O., Shapiro, B., Cui, P., Schuenemann, V. J., Sawyer, S. K., Greenfield, D. L., ... & Wayne, R. K. (2013). Complete mitochondrial genomes of ancient canids suggest a European origin of domestic dogs. Science, 342(6160), 871-874.
Vilà, C., Savolainen, P., Maldonado, J. E., Amorim, I. R., Rice, J. E., Honeycutt, R. L., ... & Wayne, R. K. (1997). Multiple and ancient origins of the domestic dog. Science, 276(5319), 1687-1689.
Wang, G. D., Zhai, W., Yang, H. C., Fan, R. X., Cao, X., Zhong, L., ... & Zhang, Y. P. (2013). The genomics of selection in dogs and the parallel evolution between dogs and humans. Nature communications, 4, 1860.
A lovely introduction to our furry friends. I was very interested to read that serotonin levels appear to be evolving in parallel between humans and dogs. Why do you think that Wang et al. (2013) suggest there is a need for less aggression in a crowded environment? I would think that the more crowded, the more “tetchy” people (and dogs) would become. I’m excited about what’s to come in this blog.
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