Life

Paleontology

First Family’s last stand

New evidence indicates that about 3.2 million years ago, at least 17 Australopithecus afarensis individuals were killed at the same time by large predators at an eastern African site.

Animals

Ballistic defecation: Hiding, not hygiene

Evading predators may be the big factor driving certain caterpillars to shoot their waste pellets great distances.

Animals

Toothy valves control crocodile hearts

The odd cog teeth of the crocodile heart may be the first cardiac valve known to control blood flow actively.

Plants

Any Hope for Old Chestnuts?

Next year will mark the 100th anniversary of the discovery of chestnut blight in the United States, but enthusiasts still haven't given up hope of restoring American chestnut forests.

Paleontology

Ancestors Go South

A group of new and previously excavated fossils in South Africa represents 4-million-year-old members of the human evolutionary family, according to an analysis of the sediment that covered the finds.

Animals

Chicks open wide, ultraviolet mouths

The first analysis of what the mouths of begging birds look like in the ultraviolet spectrum reveals a dramatic display that birds can see but people can't.

Paleontology

Feathered fossil still stirs debate

More than 2 years after scientists first described 120-million-year-old fossils of a feathered animal, a new analysis seems to bolster the view that the turkey-size species was a bird has-been and not a bird wanna-be.

Animals

Slavemaker Ants: Misunderstood Farmers?

A test of what once seemed too obvious to test—whether ant colonies suffer after being raided by slavemaker ants—suggests that some of the raiding insects have been getting unfair press.

Animals

Fishy Paternity Defense: Bluegill dads: Not mine? Why bother?

Bluegill sunfish have provided an unusually tidy test of the much-discussed prediction that animal dads' diligence in child care depends on how certain they are that the offspring really are their own.

Paleontology

Fertile Ground: Snippets of DNA persist in soil for millennia

Minuscule samples of sediment from New Zealand and Siberia have yielded bits of DNA from dozens of animals and plants, including the oldest DNA sequences yet found that can be traced to a specific organism.

Ecosystems

At a Snail’s Place: Rock climbing cuts mollusk diversity

As rock climbing soars in popularity, some cliff-side snail populations may be crashing.

Animals

Costly Sexiness: All that flash puts birds at extra risk

Distinctive his-and-her plumages increase the chance that a bird species will go extinct locally, according to an unusually far-ranging study.