Evolutionary biology

Spandrels

I had to look it up. The word “spandrel” was originally an architectural term, then was adopted by biologists to describe just what the comic says.

Evolutionary biology uses the term spandrel for features of an organism arising as byproducts, rather than adaptations, that have no clear benefit for the organism’s fitness and survival. In response to the position that spandrels are just small, unimportant byproducts, Gould and Lewontin argue that “we must not recognize that small means unimportant. Spandrels can be as prominent as primary adaptions”. A main…

Is Free Will an Illusion?

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Whether or not we act out a predetermined role in life or set our own course, has been argued for time immemorial, by philosophers, scholars, and theologians alike. Traditionally, there was an East-West dichotomy. In Eastern philosophies, generally speaking, one was the subject of fate.

People did best in this view, when they recognized their role in the universe and took part in it, wholeheartedly. In the West, humans were thought, by and large, to be imbued with free will. This comes from ancient Greece as much as the Judeo-Christian tradition. Still, free will vs. fate has been debated in the West for ages.

So which is our actual nature? Do we have free will or is it all just an illusion? With the benefits of modern science, we’re able to probe this ancient quandary in new and exciting ways. Today, neuroscientists, psychologists, and physicists have each approached the question in a different way.

Jerry Coyne is an evolutionary biologist at the University of Chicago. He says that all of our choices are determined by molecules in the brain, genes, and the environment. Sam Harris goes a step farther. He’s a philosopher and neuroscientist. Harris wrote a book about how the latest in neuroscience unravels the case for free will irreparably.

According to that field, we make decisions even before we’re consciously aware of them. Decades worth of experiments offer evidence, starting in the 1980s with EEG machines and more recently, with fMRIs and even implants, which read neurons directly inside the brain.

In 1999, psychologists Dan Wegner and Thalia Wheatley conducted a series of experiments to see how the brain made decisions. They found that there is a quarter-of-a-second lag between the time we make a choice and when our conscious mind becomes aware of it.

fMRI scan.

Brain scan studies have shown that we make decisions even before we’re consciously aware of them. Getty Images.

The implications are vast. If we could map a person’s brain in its entirety and know their complete genetic makeup, we’d be able to predict with 100% accuracy, in theory, their response to any given situation. Though American society is based on the idea of free will, such as meritocracy and the American dream, these findings from neuroscience are starting to leak into court rooms and other institutions.

Number of species depends how you count them

Hercules beetles
DRAWING LINES Scientists sometimes have difficulty determining whether organisms, such as these Hercules beetles, are members of different species. Genetic analysis alone may divide populations into species that don’t exist by other biological criteria.

Genetic methods for counting new species may be a little too good at their jobs, a new study suggests.

Computer programs that rely on genetic data alone split populations of organisms into five to 13 times as many species as actually exist, researchers report online January 30 in Proceedings of the National Academy of Sciences. These overestimates may muddy researchers’ views of how species evolve and undermine conservation efforts by claiming protections for species that don’t really exist, say computational evolutionary biologist Jeet Sukumaran and evolutionary biologist L. Lacey Knowles.

The lesson, says Knowles, “is that we shouldn’t use genetic data alone” to draw lines between species.

Scientists have historically used data about organisms’ ecological distribution, appearance and behavior to classify species. But the number of experts in taxonomy is dwindling, and researchers have turned increasingly to genetics to help them draw distinctions. Large genetic datasets and powerful computer programs can quickly sort out groups that have become or are in the process of becoming different species. That’s especially important in analyzing organisms for which scientists don’t have much ecological data, such as insects in remote locations or recently extinct organisms.

Knowles and Sukumaran, both of the University of Michigan in Ann Arbor, examined a commonly used computer analysis method, called multispecies coalescent, which picks out genetic differences among individuals that have arisen recently in evolutionary time. Such differences could indicate that a population of organisms is becoming a separate species. The researchers used a set of known species and tested the program’s ability to correctly predict…