Tag: FidoFriday

Taimyr wolf and the origins of dog

There’s an ongoing debate about where and when dogs originated. The when part might be closer to an answer now. Genetic drift is used by evolutionary biologist to try to recreate the lineage of species. The discovery of a 35,000-year-old wolf rib bone in the Taimyr peninsula in northern Siberia was the key to this story. The DNA from that bone suggests that it diverged from a common ancestor of present-day wolves and dogs near the beginning of the domestic dog lineage. Their technique uses genetic drift of ‘regular’ DNA and mitochondrial DNA.

► Genetic Drift

There are non-lethal random mutations in DNA that survive to the next generation due to natural selection and sometimes due to ‘luck’. Surviving by natural selection makes sense, a mutation affords an advantage so that offspring should excel and survive. Genetic drift is when a mutation doesn’t necessarily result in an advantage but is nevertheless passed on ‘by chance’. Tracing these mutations help create a lineage for evolutionary biologists.

► Mitochondrial DNA vs. Nuclear DNA

Mitochondria are the energy power plants inside cells. They have a few genes necessary for oxidative phosphorylation, which is a fancy term for making energy. The nucleus of the cell is where the chromosomes are. Nuclear DNA is the DNA that you hear about in the news, for example in forensic science. In the figure below, you can see that mitochondrial DNA is passed on only by the mother while nuclear DNA is passed along by both parents. Genetic drift in mitochondrial DNA is much slower and helps refine the lineage of a species. It is slower because it is only inherited by half of the genetic source, i.e., the mother.

You can read a summary of the article in layman’s terms here:

Arctic find confirms ancient origin of dogs

http://news.sciencemag.org/biology/2015/05/arctic-find-confirms-ancient-origin-dogs

Full article and source of the very cool graphical abstract:

Ancient Wolf Genome Reveals an Early Divergence of Domestic Dog Ancestors and Admixture into High-Latitude Breeds

Skoglund et al

Current Biology May 2015

http://www.cell.com/current-biology/abstract/S0960-9822(15)00432-7

Source for the mitochondria DNA figures:

University of California Museum of Paleontology’s Understanding Evolution (http://evolution.berkeley.edu) http://goo.gl/WZgKRV

A bit more reading:

How the wolf became the dog (full article behind paywall)

http://news.sciencemag.org/environment/2015/04/how-wolf-became-dog

Late for #FidoFriday  but always on time for #ScienceEveryday  

Find the scat

This is another example of how man’s best friend can work with humans to help other animals. I’m imagining Peter Lindelauf and Luna going through the woods and finding bear scat. I wonder if these dogs could help Erin Kane in her search for monkey scat. 

Happy #FidoFriday  and remember it’s #ScienceEveryday  

Originally shared by KQED SCIENCE

Dog Detectives: A Nose for Conservation

“Around the world canines are being enlisted to track rare wildlife, sleuth out invasive species, and detect otherwise imperceptible changes that could harm wilderness areas and watersheds. But are these canines really providing significant support to conservation efforts, or is it just another excuse to bring your dog to work?”

http://science.kqed.org/quest/2014/03/20/dog-detectives-a-nose-for-conservation/

Tail wagging the dog?

There was a story on NPR describing a study about asymmetrical tail wagging of dogs. In 2007 Dr. Vallortigara found that a dogs tend to wag their tail to the right when they see something friendly and wag to the left when something is threatening. In 2011 Artellea et al, used a robotic dog to see how dogs would respond to a tail wagging left or right, i.e., does the tail wagging communicate fun or danger? When dogs saw the robot tail wag left, they approached without stopping. When they saw it wag to the right, they were more cautious and stopped frequently as they approached. Dr. Vallortigara followed up his previous study, this time using a video of a dog, either wagging left or right. A group of dogs watching the video had vests, which recorded their heart rate. As expected, the heart rate was normal when the tail was wagging to the right in the video and the heart rate increased (a sign of agitation) when the tail in the video was wagging to the left. The next question is how can we use this information. It should be noted how each study builds on the previous study. That’s how science works.

The image below, from Quaranta et al, 2007, shows the angle/method for determining a left or right bias tail wag. In A the tail is wagging right and in B the tail is wagging left, i.e. left and right determinations were with respect to the dog, not the observer.

EDIT for clarity.

The Tail’s The Tell: Dog Wags Can Mean Friend Or Foe

http://goo.gl/AiHW3T via NPR 

Asymmetric tail-wagging responses by dogs to different emotive stimuli

A. Quaranta, M. Siniscalchi and G. Vallortigara

Current Biology, Volume 17, Issue 6, R199-R201, 20 March 2007

http://goo.gl/PMnx1J

Behavioural responses of dogs to asymmetrical tail wagging of a robotic dog replica

K. A. Artellea, L. K. Dumoulina & T. E. Reimchena

Laterality. 2011 Mar;16(2):129-35. 2010 Jan 19.

http://goo.gl/Mxf7BB

Seeing Left- or Right-Asymmetric Tail Wagging Produces Different Emotional Responses in Dogs

M. Siniscalchi, R. Lusito, G. Vallortigara, A. Quaranta

Current Biology, 31 October 2013

http://goo.gl/BNAENU

#ScienceEveryday   #FidoFriday  

Made for Each Other

NY Times review by Walter Vatter, http://goo.gl/MDw41, of 

What’s a Dog For?: The Surprising History, Science, Philosophy, and Politics of Man’s Best Friend by John Homans

(Amazon link: http://goo.gl/cOl94)

I haven’t read the book but I’m curious about the science claims. For example, that dogs understand gestures better than non-human primates.

#FidoFriday currated by mel peifer , Lisa Lisa, Suhaib Ayaz , and Wes Lum 

#ScienceEveryday