2010 Science News of the Year: Humans

Bones shown on black background.
Credit: Y. Haile-Selassie et al/PNAS 2010

Extreme makeover for Lucy’s kind
Recent fossil discoveries suggest that the early hominid species represented by the famous bones of Lucy, who lived 3.2 million years ago in Ethiopia, may have been more like modern humans than previously thought. The skeleton of a 3.6-million-year-old male of the same species, Australopithecus afarensis, shows that he had a nearly humanlike gait and ground-based lifestyle, says a team led by anthropologist Yohannes Haile-Selassie of the Cleveland Museum of Natural History. Dubbed Big Man, the male stood an estimated 5 to 5.5 feet tall and would have towered over the 3.5-foot-tall Lucy (SN: 7/17/10, p. 5). Big Man’s anatomy challenges an influential view, largely based on analyses of Lucy’s remains, that A. afarensis had a chimplike build suited to frequent tree climbing. The team contends that, instead, a skeleton enabling a smooth, upright stride was established by the time Lucy’s kind evolved around 4 million years ago. In another revelation, butchery marks on animal bones from about 3.4 million years ago suggest that Lucy’s species wielded stone tools, making it the oldest known group to do so (SN: 9/11/10, p. 8). Other scientists reject this claim, saying that marks found on the bones could have resulted from trampling by animals or from incidental movement across abrasive soil following burial (SN: 12/18/10, p. 8).

Wandering minds A cell phone–based survey finds that people frequently feel worse when their minds wander than when they focus on the moment (SN: 12/4/10, p. 11).

Neandertals blown away Volcanic eruptions may have wiped out Neandertals in Europe and western Asia, clearing the region for Stone Age Homo sapiens (SN: 10/23/10, p. 12).

Bridge species Fossils discovered in a South African cave may come from a hominid species that lived nearly 2 million years ago and provided an evolutionary bridge to the Homo genus (SN: 5/8/10, p. 14).

Delayed disgust It takes kids until about age 5 to understand facial expressions of disgust, challenging the view that evolution produced an innate expression for that emotion (SN: 6/19/10, p. 10). 

Duds for tots Best-selling videos marketed as vocabulary boosters for toddlers don’t work as advertised, though some parents mistakenly think they see results (SN: 9/25/10, p. 14).

Ancient mariners Stone tools found on the Mediterranean island of Crete may have belonged to a Homo species that used rafts or other seagoing vessels to journey from northern Africa to Europe at least 130,000 years ago (SN: 1/30/10, p. 14).

Gene trek DNA extracted from 4,000-year-old hair points to a previously unknown migration of northeastern Asians into the New World about 5,500 years ago (SN: 3/13/10, p. 5).

Iceman’s demise A controversial analysis of artifacts found near a prehistoric man’s frozen body (above) in the Italian Alps argues that he was ritually buried there (SN: 9/25/10, p. 14).

Stranger beside me Young couples are better than long-term partners at discerning each other’s preferences for food, movies and home decor (SN: 11/6/10, p. 16).

Genetic victims Bullied kids who carry one form of a stress-related gene have an elevated risk of emotional problems by age 12, a study finds (SN: 6/19/10, p. 10).

Heading north Stone tools unearthed in England suggest that human ancestors settled in northern Europe at least 800,000 years ago (SN: 7/31/10, p. 5).

Memory boosts By creating associations, quizzes improve recall more effectively than just reviewing notes (SN: 11/6/10, p. 16).