Oldest domesticated dog in North America remains found

9400 years old... He appears to have been eaten.

(PhysOrg.com) -- A University of Maine graduate student has discovered evidence of the oldest identifiable domestic dog in the Americas.

Samuel Belknap III, a graduate research assistant working under the direction of Kristin Sobolik in UMaine’s Department of Anthropology and Climate Change Institute, found a 9,400-year-old skull fragment of a domestic dog during analysis of an intact human paleofecal sample.

The fact that the bone was found in human waste provides the earliest proof that humans in the New World used domesticated dogs as food sources.

Why do dogs have bigger brains than cats?

Why do dogs have bigger brains than cats? They are more sociable.

ScienceDaily (Nov. 28, 2010) — Over millions of years dogs have developed bigger brains than cats because highly social species of mammals need more brain power than solitary animals, according to a study by Oxford University.

For the first time researchers have attempted to chart the evolutionary history of the brain across different groups of mammals over 60 million years. They have discovered that there are huge variations in how the brains of different groups of mammals have evolved over that time. They also suggest that there is a link between the sociality of mammals and the size of their brains relative to body size, according to a study published in the PNAS journal.

The research team analysed available data on the brain size and body size of more than 500 species of living and fossilised mammals. It found that the brains of monkeys grew the most over time, followed by horses, dolphins, camels and dogs. The study shows that groups of mammals with relatively bigger brains tend to live in stable social groups. The brains of more solitary mammals, such as cats, deer and rhino, grew much more slowly during the same period. Read more here.