Evolution

Show Me The Science Month Day 4 How did we become human? You can ask the same question in a slightly different way: how did we become different from chimps?  Although the common ancestor that we shared with chimps 5-7 million years ago was not itself a chimp, it probably resembled modern-day chimps much more than it resembled us. Both humans and chimps have been changing under evolutionary pressure since our lineages split, but humans have obviously picked up traits that make us stand out from other modern apes, most notably our intelligence. To understand how evolution has shaped our…

On the bicentennial of Charles Darwin's birthday in February 2009, biology and medicine find themselves in crisis.  The promise of stem cell therapy has the potential to dramatically improve healthcare and a patient's well being, but it risks destroying human dignity.  At the core of this is the ethical issue of the sanctity of life. Darwinism and modern biology insist that life is the result of DNA's randomness, yet reported anomalies in evolution point to the necessity of a major paradigm shift. To solve this ethical dilemma, the questions we need to ask are: What preconditions…

Show Me The Science Day 3 Reproduction involves some tricky trade-offs for all species, and anyone who has watched a David Attenborough film knows that you can find a wide range of reproductive strategies in nature. Some animals spend their energy producing hundreds or thousands of offspring and leave them to fend for themselves. Others, like whales and humans, produce only a few offspring but expend an enormous amount of resources trying to give those offspring the best chance in life possible. Plants face a similar trade-off. They can choose to produce many energetically cheap small seeds,…

Show Me The Science Month, Day 2 How do two populations change genetically when they are subjected to different evolutionary pressures? To answer this question, many intrepid evolutionary biologists have trudged out into the field to painstakingly study wild populations, but in many cases, we can learn more by studying evolution in the lab. In a paper published the February issue of Nature Genetics, a group of Portuguese and US researchers report a study of 28 years of evolution in a set of lab fruit fly populations. Their results are an example of how studying evolution in the lab, even for…

Show me the science: 30 days of evolution blogging, day 1 Birds are the modern day descendants of dinosaurs, or as paleontologist Kevin Padian likes to say, birds are dinosaurs. But how did birds evolve from grounded, naked reptiles into plumed aviators? Evolutionary biologists have been piecing together the details for nearly 40 years, and this month, a major prediction about feather evolution has been vindicated. Xing Xu and colleagues at the Chinese Academy of Sciences report the discovery of 120 million-year-old primitive fossil feathers, whose structure matches a prediction about the…

A new analysis confirms what we already knew - the evolutionary relationships among animals are not simple and the traditional idea that animal evolution has followed a trajectory from simple to complex—from sponge to chordate—had met a dramatic exception in the metazoan tree of life. But the new study suggests that the so-called "lower" metazoans (including Placozoa, corals, and jellyfish) evolved in parallel to "higher" animals (all other metazoans, from flatworms to chordates).  They say that means Placozoans—large amoeba-shaped, multi-cellular animals—have passed over sponges and…

Why have some of our genes evolved rapidly? It is widely believed that Darwinian natural selection is responsible, but research led by a group at Uppsala University suggests that a separate neutral (nonadaptive) process has made a significant contribution to human evolution.  The researchers identified fast evolving human genes by comparing our genome with those of other primates. However, surprisingly, the patterns of molecular evolution in many of the genes they found did not contain signals of natural selection. Instead, their evidence suggests that a separate process known as biased…

The world got lucky on February 12th, 1809 with the birth of Abraham Lincoln and Charles Darwin. In the United States, Lincoln's 200th birthday will be celebrated in acknowledgement that he was possibly the greatest president in U.S. history. It's become cliché to compare our veneration of Lincoln with Darwin's notoriety during this bicentennial year, but the contrast is striking. Darwin is often perceived by the public as obsolete at best (and inspired by Satan at worst). A large number of people, even many who aren't biblical literalists, are under the impression that evolutionary biology…

For those of you who still are not reading Evolution: Education and Outreach, here's another reason to check it out. Eugenie Scott and Glenn Branch of the National Center for Science Education have a nice article coming out in the next issue entitled Don't call it Darwinism. It is already free to access in preprint. While you're at it, you can have a look at the special issue on eye evolution, and my first contribution to a series entitled "Evolutionary Concepts" on artificial selection. _______________________________________________________ Click here to shop for your Darwin Year gear

Do you enjoy hunting or eating seafood?  If so, then you are an agent of detrimental evolutionary change. In the past, I've never thought about how my hunting hobby shapes the evolution of the organism I harvest.  A study in PNAS this week quantified the impact of harvesting selection on evolution in nature.  Harvesting selection is the uniquely human predatory behavior in which we pick the strongest, healthiest individuals and remove them from the prey population.  This type of selection stands in stark contrast to that of coyotes, wolves, lions, and pretty much every…