Human evolutionary history impacts our COVID-19 risk
One more COVID story, and then next month we promise to bring you something different. Evolution underlies much research on SARS-CoV-2 so it keeps popping up in important and fascinating ways:
Since the beginning of the pandemic, scientists have wondered why SARS-CoV-2 affects people so differently. Some wind up on life support or die, while others don’t even notice they are infected. Most factors that tip this balance turned out to be more environmental than evolutionary. We now know that smoking, obesity, and conditions like cancer and diabetes can make COVID-19 more dangerous. Other research highlights how social inequalities and racial disparities contribute to higher infection, hospitalization, and death rates in some groups (e.g., Black and Hispanic Americans). However, studies have also revealed gene variants associated with increased risk, and one set of these has a deep evolutionary history among not just humans, but our ancient relatives: Neanderthals.Read more »
Have long wings, will travel
This year, many Americans are refraining from holiday travel to slow the spread of COVID-19. While we are stuck at home, though, many of us can look out the window or take a walk to appreciate a different sort of annual trek, one that continues in full swing … or, in this case, full wing. During their annual migration in the fall, monarch butterflies travel from their summer range across North America to warmer sites in Mexico and the southern United States, where their food plant (the milkweed Asclepia) is available even in the dead of winter. They make the return trip in the spring. In the last few weeks, monarchs have been spotted in most southern U.S. states and in central Mexico as they leave the cold weather behind. This trip is a true family affair. No single butterfly will live long enough to make the entire return trip; instead they breed en route. However, some monarchs skip the family vacation entirely. Over the last 200 years, monarchs have spread around the world, seeding populations that stay put and don’t migrate at all. Now, new research reveals the evolution that accompanied and follows these colonizations.Read more »
La historia evolutiva del ser humano afecta nuestro riesgo de padecer COVID-19
Les compartimos un relato más sobre el COVID, y el mes próximo prometemos traerles algo diferente. La evolución es la base de muchas investigaciones sobre el SARS-COV-2, que sigue emergiendo presentando contenido importante y apunta a caminos fascinantes de investigación.
Desde el principio de la pandemia, los científicos se han preguntado por qué el SARS-CoV-2 afecta a la gente de forma tan diferente. Algunos sobreviven con ayuda de soporte vital para el resto de sus vidas, otros mueren, mientras que otros ni siquiera se enteran de que han sido infectados. La mayoría de factores que desequilibran este balance parecen estar relacionados con factores más ambientales que evolutivos. Sabemos que fumar, estar sobrepeso, o padecer de condiciones como cáncer o diabetes pueden hacer al Covid-19 más peligroso. Otras investigaciones señalan que las desigualdades sociales y las disparidades raciales o étnicas contribuyen a agravar la infección, la hospitalización, y la tasa de mortalidad en algunos grupos (ej.: lafroamericanos o hispanos/latinxs). A pesar de todo, los estudios también revelan variantes genéticas asociadas a un incremento del riesgo, y un conjunto de estas variaciones remontan a nuestra profunda historia evolutiva no entre los humanos sino entre nuestros antiguos parientes, los neandertales.Read more »
Is the coronavirus’ ability to spread evolving…or not?
Early in the pandemic, a particular mutation in the virus that causes COVID-19 (SARS-CoV-2) caught scientists’ attention. The mutation, known as D614G, makes a small change to the virus, causing a single amino acid in the spike proteins of the virus to be swapped for a different amino acid. After the mutation arose (likely in China), it spread, and lineages carrying this mutation came to dominate many outbreaks. This left scientists wondering if the D614G mutation is an adaptation that helped the virus along as it spread around the world. Since then, every month brings a new slew of studies on the mutation, along with alarming headlines. September 2020 was no exception. The Washington Post declared about a recent D614G investigation, “Massive genetic study shows coronavirus mutating and potentially evolving amid rapid U.S. spread.” And yet, many scientists question whether D614G is anything notable. Here, we’ll briefly explain the lines of evidence and a few different evolutionary explanations for what’s going on.Read more »
Evolution explains mosquitoes’ taste for human blood
This summer the coronavirus pandemic forced many residents of the northern hemisphere out of air-conditioned spaces and into the great outdoors for socially distanced get-togethers, barbecues, playdates, drive-in movies, and dining. There, we became the de facto buffet for biting insects. While we balanced our drinks, mosquitoes also had a sip … of human blood. New research published this summer explains why some mosquitoes just can’t leave humans alone, while others prefer a nice, juicy guinea pig. The answer, of course, comes down to evolution…Read more »
Tracking COVID-19 outbreaks with evolution
Earlier this month, an autopsy revealed that COVID-19 began killing people in the United States weeks before we noticed. The earliest COVID-19 death now appears to be a Californian who died on February 6, 2020, not the Washington State residents who died 20 days later, the previous “first” deaths. The newly discovered coronavirus victims had not traveled recently and probably caught it from someone in the community. This suggests that the virus was spreading person-to-person in the U.S. earlier than previously believed. The revised timeline also fits well with new evidence collected by scientists who use evolutionary techniques to unveil the sources and course of COVID-19 outbreaks.Read more »
The deep evolutionary history of the new coronavirus
For the past month, news of the pandemic coronavirus, known as COVID-19, has rattled people across the U.S. and around the globe. Internationally, the nearly 1.2 million cases have resulted in more than 60,000 deaths. Businesses have shuttered, jobs have disappeared, large swaths of the population have been asked to shelter in their homes, and many others have been left homeless, hungry, and scared. Our last Evo in the news story explained how evolutionary theory helps answer important questions about the origin of the pandemic. This month we’ll dig even deeper into the virus’s evolutionary history and how those deep relationships relate to prospects for a vaccine.Read more »
Evolution of an outbreak
For the past month, each day has brought worrisome news: more cases of the new coronavirus popping up around the world. This virus was first identified in Wuhan China, just two months ago. Since then it has spread to Southeast Asia, Australia, Europe, and North America. While the virus is no Ebola — its symptoms are much like those of the flu — it is much more transmissible than Ebola and still deadly, killing around 3% of those sickened. New diseases, like this coronavirus, Ebola, SARS, and MERS, might seem to appear out of nowhere. But in fact, these diseases are merely new to us humans. They have all been infecting other species for a long time and only recently made the evolutionary leap to humans.Read more »
A “new mode” of evolution?
In the age of clickbait, headlines are best consumed with more than a grain of salt. Is Thailand really in for a “Viral Rampage!” of the new coronavirus? Is Kim Jong-un’s aunt actually “Back from the Dead?” Did the United States literally cut a deal with killer pirates? Possibly…but more often than not, the truth is less sensational. So when a science news site exclaims over the “new mode of evolution” recently uncovered by scientists (as the website LiveScience did last month), it’s worth digging deeper…Read more »
Experimenting with evolution to fight bacteria
Pseudomonas aeruginosa is a killer. This bacterium causes thousands of deaths each year in the United States and was recently placed on the World Health Organization’s list of 12 antibiotic resistant pathogens that pose the most serious threats to human health. P. aeruginosa tends to hit people when they are down — already in the hospital recovering from some other injury or disease. In this setting, the bacterium is exposed to many different drugs, encouraging the evolution of antibiotic resistance. There, it also encounters many different bacteria, allowing the microbe to acquire from these other lineages bits of DNA that contain genes for resistance to still other antiobiotics. The result is deadly pathogen that is extremely difficult to fight. But scientists have not given up hope. Now, new research suggests that we may be able to exploit the bacterium’s own evolutionary tendencies to beat it.Read more »