No Evolution for 2 Billion Years

Scientists examining microfossils of deep-sea sulfur bacteria from Western Australia's coast found them virtually indistinguishable from those in older samples and the same sulfur bacteria today, an example of more than 2 billion years of no evolution in a static environment that confirms rather than challenges current evolutionary theory.

Primate Duplicate Genes

Small fragments of DNA called core duplicons replicated and spread across the chromosomes of select primates between 8 million and 12 million years ago, a genetic characteristic not found in other animals and an evolutionary trait that may have "seeded" chromosomal development and fundamentally influenced human evolution and brain size.

"Ardi" Links to Human Lineage

New research comparing the well-preserved cranial base of the contested 4.4 million-year-old African primate species Ardipithecus ramidus ("Ardi") found in Ethiopia reveals a closer evolutionary relationship to Australopithecus and modern humans rather than to apes, placing the species in the human evolutionary lineage.

Snakes Fastest to Evolve

With the first two full snake genomes (Burmese python, king cobra) fully sequenced, scientists have found snakes have the fastest rate of genetic evolution among vertebrates with the strongest changed genes involving body shape, metabolism and venom production.

Algae Forced into Multicellularity

Using a centrifuge technique, biologists have forced a single-celled alga (Chlamydomonas reinhardtii) to evolve and cluster into a true multicellular organism, compressing the hundreds of millions of years of evolution of multicellular life into a sufficiently short timeframe for real-time study.

Complete Skull of Homo erectus

Anthropologists have found the entire skull of a Homo erectus dating back some 1.8 million years in Georgia, the earliest complete specimen yet found and so perfectly preserved it suggests the human ancestor was more variable in appearance than previously believed with several classified subspecies such as H. habilis and H. rudolfensis simply belonging to this single species.

Functioning Gears in Nature

Scientists have found the first example of a naturally occurring gear mechanism in the hind leg joint structure of the plant hopper (Issus coleoptratus) featuring interlocking cog teeth that ensure a coordinated thrust when the insect jumps with a mechanical synchronization beyond what is capable with the nervous system.

Evolution Through Exaptation

A new quantitative study gives further support to the new biological concept of exaptation, an evolutionary phenomenon introduced in 1982 by Stephen Jay Gould and Elisabeth Vrba as a counterpart to adaptation by which existing traits are co-opted for new and advantageous uses unrelated to their biological origin.

Convergent Evolution in Genes

Geneticists studying 2326 genes in 22 mammal species have found widespread "convergence signatures" in over 200 regions for biological traits, showing that convergent evolution of similar anatomical and functional features such as sight and echolocation across unrelated species is more widespread at the molecular level than previously thought.

Earth's Life on Land Much Older

A recent study presents newly discovered tiny fossils (Diskagma buttonii) found in ancient soil samples and comparable to modern Geosiphon fungi as evidence of land-based life on Earth, pushing back estimates of its first appearance from 500 million years to 2.2 billion years ago.

Oldest Primate Fossil Found

Scientists have discovered the near-complete fossil remains of a tiny ancestor (Archicebus achilles) of the tree-dwelling primates called tarsiers that lived 55 million years ago, providing the earliest evidence of the split of the tarsier and anthropoid groups and the earliest primate fossil yet recorded.

Earliest Bird Ancestor Found

A 150 million-year-old fossil found in China's Liaoning Province and left unidentified in a local museum has been classified as the earliest known bird ancestor (Aurornis xui), with implications that flight evolved in dinosaurs only once in the lineage leading to modern birds.

Flying vs. Diving in Birds

A new study examining diving seabird species murres (Uria lomvia) and cormorants (Phalacrocorax pelagicus) finds these birds possess the most energetically inefficient wings for flight, concluding that flightless birds such as penguins lost their ability to fly as the adaptations for an aquatic lifestyle are unsuitable to maintain flight.

Testing Cope's Rule

Scientists using statistical modeling methods to compare dinosaur femurs have verified Cope's Rule that smaller animals always evolve into larger sizes with no upper limit, with exceptions for structural function between clades such as theropods (two legs) versus sauropods and ornithopods (four legs).

Longer Lives of Females in DNA

Researchers studying the mitochondrial DNA of fruit flies have found that mutations in male DNA affecting how long they live and how fast they age are not continued to subsequent generations as only the female mitochondrial DNA is passed to offspring, providing a clue why females of many species consistently outlive males.

One Gene Made Human Brains

Researchers have determined that a single gene (SRGAP2) duplicated itself 3.5 million years ago and then duplicated itself again 1 million years later, with the effect of this rare duplication slowing down the maturation of the human brain and giving it more time to develop its modern complexity.

Modern Brains from Simple Worms

New research on the simple acorn worm (Saccoglossus kowalevskii) reveals it possesses three clusters of cells called signalling centers identical to those in vertebrates that are used to develop complex brain structures, suggesting the last common ancestor of vertebrates and invertebrates may have had a complex brain that it subsequently lost.

Taste Loss in Obligate Carnivores

Researchers have established a correlation between obligate carnivores (animals subsisting only on meat) and the inability to taste sweet compounds, with the gene that controls the sweet taste receptor lost through the species' evolution and demonstrating the importance of an animal's dietary needs in shaping their sensory systems.

Horses Shrank as Planet Warmed

New research shows that an ancestor to the modern horse (Sifrhippus sandrae) living 56 million years ago shrank in size with the warming of Earth's climate over the 175,000-year Paleocene-Eocene thermal maximum, the first data to confirm Bergmann's rule applies to changes over time as well as location.

Y Chromosome Not Going Extinct

Researchers studying rhesus macaques have found the male Y chromosome still contains 20 out of 800 genes that match the X chromosome, with 19 of these shared with humans, indicating the Y chromosome has held steady for at least 25 million years and is not bound for extinction, as predicted by some evolutionary theories.