Two recent science stories have to do with the evolution of birds. One, from Science, is about the recovery of soft tissue from 68 million-year-old Tyrannoraurus Rex fossil, and the finding that the proteins it contained were more similar to those found in chickens than any other living species.
Is the chicken the closest living relative of the extinct Tyrannosaur? If so, the dinosaur's DNA must have contained some genes for more than mere ferocity - the chicken's success seems to be connected to its ability to be domesticated.
The second story is about the intelligence of ravens.
As many people have long suspected, it turns out that ravens are really intelligent: a lot smarter than most other animals, in fact.
It was reported in last month's Scientific American that ravens were able to accomplish complicated tasks, involving logic, something that few non-human animals can do. In the study, ravens were challenged to get some food that was attached to a string suspended from the perch. In order to get the treat, the ravens had to pull the string up a bit at a time, holding the part already gathered in place, until the food was pulled up to the top. Mature ravens studied the situation for minutes on end, then completed the operation in a single try.
This seems like an amazing display of logic, akin to watching a chess grandmaster study the board for several minutes, then suddenly declare "Checkmate!" while making a decisive, brilliant move. How many people are capable of analyzing an unfamiliar situation based on visual observations only, and then proceed to solve it, in one try and with no mistakes?
Combined with the other story, linking the Tyranosaurus Rex to a chicken, it makes one wonder about the genetic heritage of birds.
The authors of the raven study hypothesized about what factors in its evolution could have led to ravens developing the ability to use logic, rather than the sort of trial-and-error problem-solving exhibited by many other animals, including other types of birds.
They concluded that ravens, being primarily scavengers who are dependent on the behavior of unpredictable predators for their food, could have been selected for the ability to "think things through" before taking action. Also, ravens have a very poor sense of smell, reiforcing their need to use visual memory to navigate their surroundings and stored food caches.
The tyrannosaur, a top predator, probably faced no selection pressure to be smart. Its closest living relative is the chicken.
The intelligence of ravens reminds us of the evolutionary advantage of being forced to make difficult, potentially life-threatening choices to survive.