Bred for endurance, they can run alongside horse-drawn carriages all day ... of the majority of dog breeds is a relatively recent phenomenon, beginning with selective breeding practices during ...

Still, they're all part of the same species. The Science of Dogs blog put together a side-by-side comparison of several popular breeds from the 1915 book "Dogs of All Nations" by Walter Esplin ...

"What surprised us was that this fish has a prolonged breeding season, lasting almost five months, and that its oocytes are quite large, reaching over 3 mm in diameter." Over two years, from ...