Question

1. Why is covid-19 so dangerous, in terms of its adaptations? How can we use molecular evolution to battle this virus?

2. Why are adaptations relative?

3. What are some misconceptions about Natural Selection and adaptation? What is the evidence refuting those misconceptions?

Answer 1

Scientists are racing to understand the coronavirus disease, Covid-19, which is now a fast-growing global pandemic. The number of confirmed cases worldwide has exceeded 200,000 — and many epidemiologists believe the real total of infections may be close to a million because testing and reporting are so incomplete.

Though Covid-19 has passed its peak in China, cases in some western countries are doubling or tripling every week. Public health experts fear the respiratory illness, which is believed to have started in a food market in Wuhan, will be at least as bad as Spanish flu in 1918-19.

Covid-19 is transmitted much more readily between humans than its closest relation, Sars, which caused outbreaks of serious disease in a few countries in 2003. The new coronavirus is, however, less dangerous to most people it infects than Sars. Computer modelling suggests that each new Covid-19 case infects 2.5 other people on average when no effort is made to keep people apart. The Chinese authorities have greatly reduced this “reproduction number” through drastic action to isolate cases and trace their contacts — and the rest of the world is rapidly introducing social distancing measures.

The virus has caused severe respiratory disease in about 20 per cent of patients and killed more than 3 per cent of confirmed cases. Sars killed 10 per cent of infected individuals. Older people, whose immune defences have declined with age, as well as those with underlying health conditions, are much more vulnerable than the young.

But fatality rates are hard to estimate in the early stages of an epidemic and depend on the medical care given to patients. For example, ventilators save lives by enabling people with pneumonia to breathe. Most experts believe the current fatality rate is exaggerated by serious under-diagnosis of mild cases; the best current estimate is that Covid-19 will kill around 1 per cent of those infected in a population with good healthcare.

For comparison, seasonal flu has a mortality rate below 0.1 per cent but it infects so many people that it results in about 400,000 deaths a year worldwide. Spanish flu infected an estimated 500m people and killed 50m worldwide . Hypothetically, if Covid-19 affected half the world’s current population over the course of a year with a 1 per cent fatality rate, the death toll would be 35m — substantially increasing the number of deaths worldwide, which is around 60m for all causes in a typical year.

The virus multiplies within the lower respiratory tract, where symptoms develop. Early ones are a fever and cough. Most people will recover within a few days. But about 20 per cent go on to develop serious pneumonia as their lungs become inflamed; they may need a respirator to help them breathe.

In some of the most severe cases, there can be a fatal “cytokine storm” in which the immune system goes into overdrive, overwhelming the body with cells and proteins that destroy other organs.

• The local outbreak by exposure in the aforementioned food wholesale market marks the first phase. From the first case in December 2019 to the emergence of new cases outside Wuhan by January 13, 2020, a total of 41 cases were confirmed. Epidemiologic analysis showed that already in this initial phase, person-to-person transmission had occurred by close contact . The second phase started on January 13, marked by rapid expansion and spread of the virus within hospitals (nosocomial infection) and by family transmission (close-contact transmission). In this phase the epidemic spread from Wuhan to other areas.
• Major initial symptoms of COVID-19 include fever, cough, muscular soreness, and dyspnea. Some patients showed atypical symptoms, such as diarrhea and vomiting.
• 2. As COVID-19 continues to spread rapidly across the globe, we at IPA—like all of you—have been closely monitoring this rapidly evolving situation and adapting our lives and our work as a result. We have been consulting widely to determine the best course of action to keep our staff and the communities they interact with as safe as possible, and to do this we have benefitted from the best practice advice of other international organizations and health and safety experts.

• In addition to the first and most urgent priority of protecting health and safety, we feel it is our responsibility to adapt during this time so that we can contribute meaningful data, evidence, and analysis to the response to this crisis. Our research and programs teams are already exploring ways that we can adapt our work and leverage our institutional comparative advantage and staff in 22 country offices to support the response effort .

• 3.Although evolutionary theory is considered to be a unifying foundation for biological education, misconceptions about basic evolutionary processes such as natural selection inhibit student understanding. Even after instruction, students harbor misconceptions about natural selection, suggesting that traditional teaching methods are insufficient for correcting these confusions. This has spurred an effort to develop new teaching methods and tools that effectively confront student misconceptions. In this study, we designed an interactive computer-based simulated laboratory to teach the principles of evolution through natural selection and to correct common student misconceptions about this process. We quantified undergraduate student misconceptions and understanding of natural selection before and after instruction with multiple-choice and open-response test questions and compared student performance across gender and academic levels. While our lab appeared to be effective at dispelling some common misconceptions about natural selection, we did not find evidence that it was as successful at increasing student mastery of the major principles of natural selection. Student performance varied across student academic level and question type, but students performed equally across gender. Beginner students were more likely to use misconceptions before instruction. Advanced students showed greater improvement than beginners on multiple-choice questions, while beginner students reduced their use of misconceptions in the open-response questions to a greater extent. These results suggest that misconceptions can be effectively addressed through computer-based simulated laboratories. Given the level of misconception use by beginner and advanced undergraduates and the gains in performance recorded after instruction at both academic levels, natural selection should continue to be reviewed through upper-level biology courses .