Okay, maybe the word alone doesn't sound like much. But according to new research from Britain, "thou" may be one of the most enduring breadcrumbs of language in human evolutionary history.

In this study, a team of linguists from the University of Reading found clues that many modern languages — including but not limited to English, Russian, Portuguese, and more — descended from a single ancestral tongue some 15,000 years ago. "Everybody in Eurasia can trace their linguistic ancestry back to a group, or groups, of people living around 15,000 years ago, probably in southern Europe, as the ice sheets were retreating," Mark Pagel, an evolutionary biologist at Reading University, tells the Guardian.

How did researchers figure this out? They looked at a small handful of words in several languages that resemble each other in sound, look, and meaning. These kindred terms — like father (English) and Padre (Italian) — are referred to as "cognates."

Using these similar-sounding words as road markers, the team unearthed 23 "ultraconserved words" that, at the very least, would have sounded vaguely familiar to our ancient ancestors 150 centuries ago. According to the Washington Post, these entries include "mother," "not," "what," "man," "hand," "thou," "spit," and several others. (See the rest of the examples in a PDF here.)

All 23 ultraconserved words were found to have a common ancestry 15,000 years ago. And taken together, this special linguistic group's ability to persevere throughout the centuries tells us something about humankind's fundamental need to communicate. (It's easy to see how "mother," "fire," and "man" may have been instrumental to an ancient community's survival, for example.)

While not every language falls within this proto-Eurasiatic lineage — Chinese, many African languages, and the languages of Native Americans are outliers, for example — Pagel and his team of linguists drew a family tree tracing these ultraconserved words back through the seven modern language families. David Brown at the Washington Post reports:

In addition to Indo-European, the language families included Altaic (whose modern members include Turkish, Uzbek and Mongolian); Chukchi-Kamchatkan (languages of far northeastern Siberia); Dravidian (languages of south India); Inuit-Yupik (Arctic languages); Kartvelian (Georgian and three related languages) and Uralic (Finnish, Hungarian and a few others). [Washington Post]

So how does our original pronoun, "thou," fit in? According to researchers, it's the only word to have a cognate in all seven language families.