Gene

Yale Researchers Find That Autism Genes Helped Us to Become Smarter

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Those with autism face distinct challenges. These usually have to do with certain social deficits. That might be why the results of a new study appear a bit puzzling. Genes linked to autism spectrum disorders (ASD) were actually preserved through the process of evolution, Yale researchers concluded. These genes actually made us smarter.

If you find these results strange, consider the large numbers of scientists and engineers known to have Asperger’s syndrome. There are autistic savants as well, as the movie Rain Man can attest, which was based on a true story. Or perhaps you’ve seen the work of mind-blowing artist Stephen Wiltshire, who can draw panoramic scenes of whole cities with perfect detail, from his memory alone.

This was a genome-wide study, zeroing in on gene variants associated with ASD. Researchers examined 5,000 cases of autism and analyzed the genome of each participant. They focused on evolutionary gene selection, particularly on which genes were positively selected. One clue which led researchers to these findings was that, more genes associated with autism were preserved by evolution than would have been through sheer randomness.

Autistic…

Competition, Cooperation, and the Selfish Gene

Richard Dawkins has one of the best-selling books of all time for a serious piece of scientific writing.

Often labeled “pop science”, The Selfish Gene pulls together the “gene-centered” view of evolution: It is not really individuals being selected for in the competition for life, but their genes. The individual bodies (phenotypes) are simply carrying out the instructions of the genes. This leads most people to a very “competition focused” view of life. But is that all?

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More than 100 years before The Selfish Gene, Charles Darwin had famously outlined his Theory of Natural Selection in The Origin of Species.

We’re all hopefully familiar with this concept: Species evolve over long periods time through a process of heredity, variation, competition, and differential survival.

The mechanism of heredity was invisible to Darwin, but a series of scientists, not without a little argument, had figured it out by the 1970’s: Strands of the protein DNA (“genes”) encoded instructions for the building of physical structures. These genes were passed on to offspring in a particular way – the process of heredity. Advantageous genes were propagated in greater numbers. Disadvantageous genes, vice versa.

The Selfish Gene makes a particular kind of case: Specific gene variants grow in proportion to a gene pool by, on average, creating advantaged physical bodies and brains. The genes do their work through “phenotypes” – the physical representation of their information. As Helena Cronin would put in her book The Ant and the Peacock, “It is the net selective value of a gene’s phenotypic effect that determines the fate of the gene.”

This take of the evolutionary process became influential because of the range of hard-to-explain behavior that it illuminated.

Why do we see altruistic behavior? Because copies of genes are present throughout a population, not just in single individuals, and altruism can cause great advantages in those gene variants surviving and thriving. (In other words, genes that cause individuals to sacrifice themselves for other copies of those same genes will tend to thrive.)

Why do we see more altruistic behavior among family members? Because they are closely related, and share more genes!

Many problems seemed to be solved here, and the Selfish Gene model became one for all-time, worth having in your head.

However, buried in the logic of the gene-centered view of evolution is a statistical argument. Gene variants rapidly grow in proportion to the rest of the gene pool because they provide survival advantages in the average environment that the gene will experience over its existence. Thus, advantageous genes “selfishly” dominate their environment before long. It’s all about gene competition.

This has led many people, some biologists especially, to view evolution solely through the lens of competition. Unsurprisingly, this also led to some false paradigms about a strictly “dog eat dog” world where unrestricted and ruthless individual competition is deemed “natural”.

But what about cooperation?

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The complex systems researcher Yaneer Bar-Yam argues that not only is the Selfish Gene a limiting concept biologically and possibly wrong mathematically (too complex to address here, but if you want to read about it, check out these pieces), but that there are more nuanced ways to understand the way competition and cooperation comfortably coexist. Not only that, but Bar-Yam argues that this has implications for optimal team formation.

In his book Making Things Work, Bar-Yam lays…

Bacteria genes offer new strategy for sterilizing mosquitoes

wolbachia bacteria
STERILITY CULPRITS Wolbachia bacteria (red) effectively sterilize a male mosquito by infecting the insect’s testes (blue), shown at 100 times magnification. Now, researchers have identified genes that may be responsible for the sterility.

A pair of bacterial genes may enable genetic engineering strategies for curbing populations of virus-transmitting mosquitoes.

Bacteria that make the insects effectively sterile have been used to reduce mosquito populations. Now, two research teams have identified genes in those bacteria that may be responsible for the sterility, the groups report online February 27 in Nature and Nature Microbiology.

“I think it’s a great advance,” says Scott O’Neill, a biologist with the Institute of Vector-Borne Disease at Monash University in Melbourne, Australia. People have been trying for years to understand how the bacteria manipulate insects, he says.

Wolbachia bacteria “sterilize” male mosquitoes through a mechanism called cytoplasmic incompatibility, which affects sperm and eggs. When an infected male breeds with an uninfected female, his modified sperm kill the eggs after fertilization. When he mates with a likewise infected female, however, her eggs remove the sperm modification and develop normally.

Researchers from Vanderbilt University in Nashville pinpointed a pair of genes, called cifA and cifB, connected to the sterility mechanism of Wolbachia. The genes are located not in the DNA of the bacterium itself, but in a virus embedded in its chromosome.

When the researchers took two genes from the Wolbachia

Human genes often best Neandertal ones in brain, testes

Neandertal brain
BRAIN ACTIVITY Human versions of some genes are more active in certain parts of the brain than Neandertal versions. Side and back views of a brain show that activity levels of the Neandertal version of a gene called NTRK2 are lower in the cerebellum (blue area in lower back) than in other regions.

Humans and Neandertals are still in an evolutionary contest, a new study suggests.

Geneticist Joshua Akey of the University of Washington in Seattle and colleagues examined gene activity of more than 700 genes in which at least one person carried a human and a Neandertal version of the gene. Human versions of some genes are more active than Neandertal versions, especially in the…

How a Jellyfish Gene Can Make Glow-in-the-Dark Beer

The intrepid home brewer can now create a truly unique beer. The ODIN, a company that sells DIY science kits, has created an at-home brewing kit that lets you create glowing beer, as Eater reports.

The bioluminescent beer gets its glow from a jellyfish gene in the genetically modified yeast. Jellyfish-derived fluorescence has…