Appendages of fish, mice spring from common genes
The genes that lead to the development of hands and feet in mice are also involved in the development of fins in fish, suggesting that modern land animals' limbs evolved from the fins of ancient fish ancestors, according to a study published in the Proceedings of the National Academy of Sciences. "Fossils show that the wrist and digits clearly have an aquatic origin. But fins and limbs have different purposes. They have evolved in different directions since they diverged," said organismal biologist Neil Shubin. LiveScience.com
(12/22)
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Scientists use oldest stone tool to help track early humans' movements
The oldest stone tool has been found in Turkey and is giving researchers clues about early humans' movements. The tool is a small, quartzite flake used by early humans over a million years ago. "This discovery is critical for establishing the timing and route of early human dispersal into Europe. Our research suggests that the flake is the earliest securely dated artifact from Turkey ever recorded and was dropped on the floodplain by an early hominin well over a million years ago," said Danielle Schreve, co-author of the study published in Quaternary Science Reviews. LiveScience.com
(12/24)
Researchers find ancient bracelet embossed with menorahs in Israel
An ancient glass bracelet embossed with menorahs has been found in Israel's Mount Carmel National Park. The bracelet dates back to the late Roman or early Byzantine period, according to researchers. "After cleaning, we were excited to discover that the bracelet, which is made of turquoise colored glass, is decorated with symbols of the seven-branched menorah -- the same menorah which according to tradition was kept alight in the temple for eight days by means of a single cruse of oil," said Israel Antiquities Authority excavation directors Limor Talmi and Dan Krizner in a statement. LiveScience.com
(12/23)
Human primordial germ cells created in a lab
Scientists have found a way to create human primordial germ cells, or PGCs, in a lab, and saying that they are significantly different than those of mice, calling into question the efficacy of mouse experiments as related to human cell development. "Mechanisms of early cell fate decisions in mice cannot be safely or wholly extrapolated to specification events during early human development," suggest the authors of the study, published in the journal Cell. Scientists from the University of Cambridge in the U.K. and the Weizmann Institute of Science in Israel reprogrammed human embryonic stem cells and induced pluripotent stem cells to create the PGCs. Los Angeles Times (tiered subscription model)/Science Now blog
(12/24)
Reality, imagination flow in different directions in brain, study suggests
Reality and imagination move in different directions in the brain, with visual information from what the eyes see flowing up from the occipital lobe to the parietal lobe, and images concocted in the imagination flowing down to the occipital to the parietal, according to a study published in NeuroImage. The flow that the study's authors refer to is the general direction taken by neural signals. "Our study represents the first direct measure of the prevalence of top-down signal flow during imagery," said lead author Daniela Dentico. LiveScience.com
(12/23)
Researchers develop biochip to assess sickle cell disease
Researchers at University Hospitals Case Medical Center and Case Western Reserve University have developed and begun testing a biochip that evaluates sickle cell disease activity by measuring the flow of red blood cells. Researchers are enrolling up to 100 children and adults for a study that compares the biochip's measurements with clinical characteristics of the disease. The Plain Dealer (Cleveland)
(12/23)
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