My earlier post on the origins of complexity sparked an interesting and informative discussion in the comments so I thought I would pass on another article about it by Amy Maxmen that I came across later, that looked at the same question in light of what we know about the seemingly lowly amoeba. She starts by posing the problem. [Read more…]

A crucial step in the evolution of complex organisms is the appearance of multicellularity. Key questions are “how did multicellularity evolve? Did it evolve once or multiple times? How did cells make the transition from life as a solo cell to associating and cooperating with other cells such that they work as a single, cohesive unit?” [Read more…]

Life is complex. This is true not just in a rhetorical sense but also biologically in that living things are complicated arrangements of multicellular life. So how did this complexity arise? The most common explanation given is that it is a natural outgrowth of natural selection and that once a self-replicating molecule formed, the selection pressures would be such that given sufficient time multicellular life would be an almost inevitable consequence, though the exact form it would take would depend on many contingencies. [Read more…]

Neurophilosopher Patricia Churchland appeared on The Colbert Report to discuss with the host some of the latest developments in neuroscience and what they shed on old philosophical questions. She had to break the news to him, a practicing Catholic, that he has no soul (because none of us do) and that our moral sense arises from the circuitry and chemical activity of the brain. It is a good interview. He actually asks some sharp questions, dealing with the kinds of concerns a religious person would have, and gives her time to respond rather than taking up a lot of the time which can be a failing of his. [Read more…]

The discovery of the Tiktaalik fossil back in 2006 was a cause of great celebration because it was a 385 million year old fossil that showed the early stages of forelimbs that indicated it was a transitional one from sea to amphibian. Neil Shubin, the leader of the team, wrote a highly engaging book Your Inner Fish that showed how much our human bides were shaped by our fishy ancestors. [Read more…]

Everyone is aware of all the reports that suggest that our cognitive powers go into decline with increased age. As a result, as some of us get into our senior years, we can’t help but identify as symptoms of that mental decline every time we do not remember some thing that we think we should, or when it takes awhile to do something that we think we used to do faster. We may joke about having ‘senior moments’ but those jokes are accompanied by a twinge of anxiety as to whether they are precursors of more serious problems to come. [Read more…]

Jordan Sargent has a remarkable photograph taken by Ingolf Kristiansen off the coast of Norway. Apparently a large number of herring were swimming close to the surface when a gust of cold wind froze the water near the surface, trapping the fish in place. I found this surprising because the phase change from water to ice is not instantaneous and one would think that as it happened the fish would go lower where it remains as water. [Read more…]

The only planet on which we know for sure that life exists is Earth. Even though this gives us just a sample of one, it is tempting to think that conditions here must be close to the ideal for life to emerge and that if there are other planets on which life exists, they must be Earth-like in terms of size and occupying the so-called ‘stellar habitable zone’ (SHZ) from its star so that the temperature range is similar to ours. [Read more…]

Those climate change deniers who gleefully seize on any cold spell in the US as evidence that global warming is a hoax conveniently ignore the fact that there is a part of the globe called the ‘southern hemisphere’ and winter here means summer there. It turns out that Australia is currently going through a blistering heat wave with elevated risks for forest fires and heat strokes. [Read more…]

Bicycle helmets undoubtedly protect users from brain injuries. But is it possible, as some studies have suggested, that the helmets make you hot and sweaty and distracted and thus increase the chances of an accident? This idea has been picked up by some who oppose mandatory helmet laws. [Read more…]