evolution

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Microbes Fly Overhead in This Year’s Solar Eclipse

When the sun vanishes behind the moon, living organisms behave as if twilight is here. Crickets start to chirp, flowers close up, and cows head to the barn.  In this year’s highly anticipated solar eclipse, microbes will also fly high in the sky on giant balloons as part of a citizen science project called the Eclipse Ballooning Project.

The Eclipse Ballooning Project harnesses the scientific curiosities of 55 teams across universities, high schools, and ballooning groups. These citizen scientists will capture footage along the path of totality across the Unites States. This will be the first time videos and images of a total eclipse will be documented live from near space. (more…)

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Why are pathogens rarely resistant to vaccines?

We have all heard the horrifying tales of incurable bacterial infections due to antibiotic resistance. But why don’t we see pathogens becoming resistant to vaccines? Intuitively, it seems that vaccines, like antibiotics, put selective pressure on pathogens. The selective force should drive the evolution of vaccine resistance, right? David Kennedy and Andrew Read explore this quandary in their recent publication in the Proceedings of the Royal Society.

Historically, when vaccine resistance arises, it takes much longer compared to antibiotic resistance. Vaccines created as early as the 1920s are still effective today while resistance to a new antibiotic can develop within a few years. Because the evolution of vaccine resistance is so rare, vaccines may be a solution to the drug resistance problems we face today. Vaccines reduce the need for antibiotic treatment and also decrease the number of cases and spread of infections. (more…)

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Bacteria’s toxic addiction to DNA

For bacteria, addiction to DNA can be a life or death situation. Lose that DNA and the bacterium suffers an unfortunate toxic death.

Many bacteria easily transfer DNA amongst themselves in the forms of plasmid DNA. Plasmids are mobile genetic elements that replicate independently of the chromosome. These small circular pieces of DNA often contain genes that provide its carrier a survival advantage under specific environmental conditions. For example, if a bacterium contains a plasmid with an antibiotic resistance gene, it can survive antibiotic treatment. But, the plasmid is not beneficial to its host cell in all situations and poses a metabolic burden for the host. So why do these plasmids exist and remain in bacteria? (more…)

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Meet a microbiologist: Eva Garmendia

Eva Garmendia has always been interested in the small and invisible since she can remember. According to Eva, she was “[amazed] that there is a universe we couldn’t see and yet, we could study and understand it.” As an undergraduate at the University of Granada, she found genetics calling her name and spent her time outside of class in a genetics lab. During that time, she became interested in evolution. While studying abroad at Uppsala University in Sweden, she began her research in microbiology and was hooked. Eva noted that her interest was sparked by “the fact that microbes were alone ruling the earth for so long before multicellularity developed.” She completed a six-month project on the role of RNases in Salmonella Typhimurium. Eva saw how microbiology could help her study evolution citing “their power of rapid replication.” (more…)

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Solving the plasmid paradox: evolutionary advantages of multicopy plasmids

Today marks the end of 2016's World Antibiotic Awareness Week, aimed to increase awareness of antibiotic resistance and to advocate for the prudent use of these drugs.

One of the key drivers of antibiotic resistance is how rapidly bacteria acquire DNA from the environment or from other bacteria. Resistance elements are often carried on mobile elements, DNA that can move around the genome or be transferred to other genomes. The almost universal rapid assimilation of DNA by bacteria leads to the acquisition of multiple antibiotic resistance genes in a variety of bacterial species. One such example of a DNA mobile element is the plasmid, small circular DNA that replicates independently of the chromosome and can be transferred from bacterium to bacterium during cell division, transformation, and conjugation. (more…)