Scientists
aren’t exactly sure how many new mutations crop up each generation
in humans—for years, the standard estimate was round 100-200, but
one
2011 study,
using whole genome information from two families, has put it at about
30-50. And the rate of mutation is more than a curiosity: Seeing how
many mutations separate us from cousin species and multiplying that
by the rate of change is one way scientists measure the time since we
diverged from each other—a “molecular clock.” So that new,
lower mutation rate—30-50 changes per generation—implies that our
common ancestor with chimps was not 5 million years ago, as had been
thought, but 7 million years. (For
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A Universal Cancer Treatment?
A medicine that disrupts the DNA replication of cancer cells may be within reach.
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After 100 Years of Research, Autism Remains a Puzzle
One geneticist is determined to piece together the causes.
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Embryo Cells Set Patterns for Growth by Pushing and Pulling
Patterns that guide the development of feathers and other features can be set by mechanical forces in the embryo, not just by gradients of chemicals.
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Life’s First Peptides May Have Grown on RNA Strands
RNA and peptides coevolving in the primordial world might have jointly served as a precursor to the modern ribosome.
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The Race to Protect Sweet Corn
Breeding a variety that can withstand disease and taste better, too.
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Plants Fight for Their Lives
As arable land disappears, a genetic tweak might secure the world’s food supply.
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The Rise of RNA Therapeutics
DNA mutations are hard to fix. Scientists are trying another approach.
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Reading Genomes: The Key to Life and to Thwarting Death
Genome sequencing machines are essential to preventing viral outbreaks, but funding is key.
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The Rise of RNA Therapeutics
DNA mutations are hard to fix. Scientists are trying another approach.
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The Hidden Link Between “Genetic Nurture” and Educational Achievement
The phrase “Look down your nose” comes from a time when aristocrats were taller than commoners due to their superior nutrition. European elites would literally look down on their inferiors. So it shouldn’t be hard to imagine the shock 19th-century aristocrats experienced, across the Atlantic, encountering well-fed American laborers, artisans, and farmers, who would look […]
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The Complex Truth About ‘Junk DNA’
Genomes hold immense quantities of noncoding DNA. Some of it is essential for life, some seems useless, and some has its own agenda.
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DNA Has Four Bases. Some Viruses Swap in a Fifth.
The DNA of some viruses doesn’t use the same four nucleotide bases found in all other life. New work shows how this exception is possible and hints that it could be more common than we think.
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Data Crunchers to the Rescue
Genetic diseases that puzzle lab scientists are being solved by quantitative biologists.
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Some Proteins Change Their Folds to Perform Different Jobs
Unusual proteins that can quickly fold into different shapes provide cells with a novel regulatory mechanism.
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The Mystery of Mistletoe’s Missing Genes
Mistletoes have all but shut down the powerhouses of their cells. Scientists are still trying to understand the plants’ unorthodox survival strategy.