Origin and evolution of life

  • Life’s Working Definition
    Finding life elsewhere in the universe depends on knowing when you see it, according to Colorado professor Carol Cleland. She gives a view of how life might not need a working definition as much as a theory of life -- at least until scientists
    more...
  • Lord of Gondwanaland
    In an ancient time, what happens when a common water-hole brings together the most clever species on our planet with its apex predator? Welcome to the ancient supercontinent of Gondwanaland, where the largest vertebrate carnivore--the gorgon--battles its smartest foe yet--the cynodont.
    more...
  • Walking Before Flying?
    The history of the lowly insect known as the 'walking stick' offers a fascinating genetic study of evolution moving backwards and forwards, in what is commonly called Dollo's Law. A team of BYU biostatisticians discusses the challenge of finding out which came first: walking or
    more...
  • Weird Life on the Mats
    The fossil record is full of animals with bizarre body shapes. Do these extinct species represent failed evolutionary experiments, or were they simply well-adapted to an environment that no longer exists?
    more...
  • Evolution’s Sweet Tooth
    How did intelligence evolve? A scientist studying differences between humans and great apes may have found a biochemical step in that direction.
    more...
  • Ripples in Time
    Until the last fifteen percent of the Earth's age, the continents were barren, lifeless wastelands. Life had yet to hit the shore. But a kind of molecular clock says the hands of time may have started ticking many billions of years earlier.
    more...
  • Stitching Together Green Genes
    How did photosynthesis arise? Astrobiologists at Arizona State University report in Science that five bacteria share enough commonality to create the current diversity of photosynthesizing chemistries but differ in how they got them.
    more...
  • Life from Scratch?
    As pioneers of the Human Genome Project announced their next target- life created de novo, or from a minimal genetic recipe- the debate heats up about what 'minimal' actually might mean when their prospective life forms start to take shape.
    more...
  • Protein Archaeologists
    New methods for time-stamping ancient fossil bones hold promise of understanding Earth's genetic past.
    more...
  • The Tree of Life: Cold Start?
    For decades, scientists have used a comprehensive tree of life showing heat-loving bacteria as the Earth's earliest bacteria. Now, a more accurate reanalysis of the data place those bacteria up among the leaves.
    more...
  • The Life That Spawned A Quarter-Million Descendant Species
    The first cellular organisms with a nucleus, called protists, now comprise nearly a quarter-million named species. Including green algae and parasites, they make up the first link in the complex food chain that not only sustains all life on Earth, but modifies terrestrial weather.
    more...
  • Studying Evolution with Digital Organisms
    Can we grasp the workings of Darwinian evolution by studying the behavior of digital organisms that exist only as strings of computer code? Scientists in Caltech's Digital Life Laboratory think so.
    more...
  • Evolution’s Sweet Tooth
    How did intelligence evolve? A scientist studying differences between humans and great apes may have found a biochemical step in that direction.
    more...
  • Encore
    Our debate panelists answer reader's questions about the possibility of complex life beyond Earth.
    more...
  • Weird Life on the Mats
    Do extinct species represent failed evolutionary experiments? At least for some more closely related to today's crabs and lobsters, University of Southern California scientist David Bottjer says that if many such early animals look strange to us, it is not because they were strange.
    more...