HHMI's Holiday Lectures on Science
Summary: HHMI's Holiday Lectures on Science The Howard Hughes Medical Institute is a philanthropy that supports biomedical research and science education. As part of its mission to strengthen science education, the Institute presents the Holiday Lectures on Science, an annual series that brings the latest developments in a rapidly moving field of research into the classroom. These lectures are videotaped and technical, but even the lay person can learn from them. Audio files are available, but you do lose the visual aids. However, they are still useable. Previous subjects have included, dengue, RNA, and the idea of quorum sensing which is how bacteria decide when to attack, or fireflies coordinate their flashing sequence.
The loss of biodiversity also means a loss of genetic diversity, which is the biological toolkit for adaptation. As populations of animals become increasingly isolated due to habitat fragmentation, assisted migration may be a strategy for preserving genetic diversity.
Ocean biodiversity is also threatened by human activities. But because the ocean is huge and has highly diverse environments, marine organisms appear to be more resilient than land animals when threatened by extinction and can bounce back with modest conservation efforts.
Coral reefs are threatened by many human activities, including global ocean warming from climate change. Some corals can survive unusually high temperatures by virtue of their genetic makeup. These heat-tolerant corals may hold the key to preserving coral reefs into the future.
The current threats to biodiversity are tightly coupled to human demand for power, food, and money. We can avoid a sixth mass extinction by rethinking how we use energy, how we feed the world, and the value we place on intact ecosystems.
A sixty minute discussion on biodiversity with the lecturers and students attending the 2014 Holiday Lectures. Moderated by HHMI vice president of Science Education, Dr. Sean Carroll.
The human brain is a complex network of cells whose organization and function are controlled by many genes. By working with patients who have developmental brain disorders, Dr. Christopher Walsh and his team have begun to identify genes that are required for proper brain development. This research has led to some surprising insights, such as a connection between cell division orientation and cell fate during the development of the cerebral cortex.
Despite decades of research, cancer continues to be a major cause of death in the United States. The disease is traditionally treated by a combination of surgery, radiation, and chemotherapy, which can have severe side effects. Recent advances in cancer biology have led to the development of targeted drugs as new and effective treatment options for some types of cancer. Dr. Charles Sawyers presents an overview of cancer biology and describes how understanding the molecular mechanisms involved in a type of cancer, chronic myeloid leukemia, resulted in the development of Gleevec, one of the first targeted cancer drugs.
Autism is a general term for a spectrum of disorders of brain development that range in severity from mild to severe. Because autism is not a single disease, it has been difficult to identify its causes. Dr. Christopher Walsh describes how recent advances in DNA sequencing technology have made it possible to study large cohorts of patients and find genes that are most commonly disrupted in children with autism. These studies show that all currently known genes associated with autism are also associated with other neurological diseases, and that they affect the mechanisms of communication between neurons.
Based on early successes with targeted drug therapy, the cancer research community prioritized sequencing the genomes of thousands of tumor samples to identify every gene mutated in cancer. Approximately 140 such genes have been identified to date. They can be classified into three main functional groups according to their roles in normal cell biology: genes that affect cell growth and survival, cell fate, and genome maintenance. Cancers can now be classified not only by the type of tissue and cell that they affect, but also by the genes that are mutated. As Dr. Charles Sawyers reveals, both types of classification are necessary for devising new, targeted therapies.
Dr. Elinor Karlsson of the Broad Institute discusses using dogs in genome-wide association studies (GWAS), and the genetic evidence for dog domestication, as revealed by copy-number variations in the amylase gene.
Dr. Charles Sawyers and Dr. Christopher Walsh discuss wide-ranging topics with students, including autism, cancer, and scientific career choices.
The fossil record contains evidence of large animals only for the most recent 15 percent of Earth's history. Before then, life on our planet consisted primarily of microbes, which have left microfossil and chemical evidence of their existence. Microbes had a profound effect in shaping Earth's environment in the past. For example, when cyanobacteria evolved oxygen-generating photosynthesis, the event led to the oxygenation of the atmosphere and the evolution of eukaryotes and animals. Today many of Earth's ecosystems continue to depend on microbes. The same methods used to study the history of life on Earth are also being used to determine whether Mars ever supported life.
Accepting a scientific theory as scientific knowledge requires broad consensus among scientists. The theory of continental drift, which eventually became known as the theory of plate tectonics, was a remarkable synthesis of different lines of evidence. Yet, when first proposed in the 1920s by Alfred Wegener, the theory was rejected by many scientists. The story of how the theory eventually became accepted, many decades later, provides a fascinating glimpse into the process of building new scientific consensus.
Changes in the atmospheric concentrations of greenhouse gases, such as carbon dioxide (CO2), influence Earth’s temperature. Geologic records show that Earth has been both much cooler and much warmer in the past compared to today, but this change in temperature was driven by a gradual rate of change in atmospheric CO2 concentrations. The rate of modern day increases in CO2 is unprecedented in human history and will have serious consequences in the near future and beyond, in terms of climate change, sea level rise, and species extinctions. Solutions to mitigate global warming are costly and challenging to implement.
There is strong consensus among climate researchers that, based on careful analysis of the scientific evidence, human activities are causing climate change. Yet, the American public remains highly skeptical of this conclusion. Why? A look at this country’s history provides the answer. A Cold-War era think tank became an influential source of anti-regulation sentiment, swaying public opinion on many issues, from the harms of cigarette smoke to acid rain, and now, climate change.