Posts about biology

Insect Architecture

In this webcast The Brain Scoop takes an interesting look at the homes of eusocial animals and other insects. The video includes many interesting details including that adult weaver ants can’t produce the silk used to weave leaves together so they pick up their larva and use them like a glue stick.

Related: For Many Crops Ants Can Provide Pest Protection Superior or Equal to Chemicals at a Much Lower CostWhy Don’t All Ant Species Replace Queens in the Colony, Since Some DoSymbiotic relationship between ants and bacteriaHuge Termite Mound in Nigeria

We are Not Us Without The Microbes Within Us

I Contain Multitudes is a wonderful book by Ed Young on the microbes within us.

Time and again, bacteria and other microbes have allowed animals to transcend their basic animalness and wheedle their way into ecological nooks and crannies that would be otherwise inaccessible; to settle into lifestyles that would be otherwise intolerable; to eat what they could not otherwise stomach; to succeed against their fundamental nature. And the most extreme examples of this mutual assured success can be found in the deep oceans, where some microbes supplement their hosts to such a degree that the animals can eat the most impoverished diets of all – nothing.

This is another book exploring the wonders of biology and the complexity of the interaction between animals and microbes.

For hundreds of years, doctors have used dioxin to treat people whose hearts are failing. The drug – a modified version of a chemical from foxglove plants – makes the heart beat more strongly, slowly, and regularly. Or, at least, that’s what it usually does. In one patient out of every ten, digoxin doesnt’ work. Its downfall is a gut bacterium called Eggerthella lenta, which converts the drug to an inactive and medically useless form. Only some strains of E. lenta do this.

The complex interactions within us are constantly at work helping us and occasionally causing problems. This obviously creates enormous challenges in health care and research on human health. See related posts: Introduction to Fractional Factorial Designed Experiments, “Grapefruit Juice Bugs” – A New Term for a Surprisingly Common Type of Surprising Bugs and 200,000 People Die Every Year in Europe from Adverse Drug Effects – How Can We Improve?.

Every person aerosolized around 37 million bacteria per hour. This means that our microbiome isn’t confined to our bodies. It perpetually reaches out into our environment.

Avoiding bacteria is not feasible. Our bodies have evolved with this constant interaction with bacteria for millions of years. When we are healthy bacteria have footholds that make it difficult for other bacteria to gain a foothold (as does our immune system fighting off those bacteria it doesn’t recognize or that it recognized as something to fight).

A few pages later he discusses the problem of hospital rooms that were constantly cleaned to kill bacteria and largely sealed to reduce airflow. What happened is those bacteria the sick people had in them were the bacteria that were flourishing (the number of other bacteria to compete for space was small). Opening the windows to welcome the outside air resulted in better results.

Outdoors, the air was full of harmless microbes from plants and soils. Indoors, it contained a disproportionate number of potential pathogens, which are normally rare or absent in the outside world

Human health is a fascinating topic. It is true antibiotics have provided us great tools in the service of human health. But we have resorted to that “hammer” far too often. And the consequences of doing so is not understood. We need those scientists exploring the complex interactions we contain to continue there great work.

Related: People are Superorganisms With Microbiomes of Thousands of Species (2013)Bacteria are Always Living in Our Bodies (2014)Gut Bacteria Explored as Medical Treatment – even for Cancer

Unexpected Risks Found In Editing Genes To Prevent Inherited Disorders

Mitochondrial replacement seeks to remove genes known to cause genetic defects from embryos in order to allow for a baby to avoid inheriting the defect.

Mitochondrial Replacement Techniques: Ethical, Social, and Policy Considerations from the USA National Academy of Sciences

Accordingly, the committee recommends that any initial MRT clinical investigations focus on minimizing the future child’s exposure to risk while ascertaining the safety and efficacy of the techniques. The recommended restrictions and conditions for initial clinical investigations include

  • limiting clinical investigations to women who are otherwise at risk of transmitting a serious mtDNA disease, where the mutation’s pathogenicity is undisputed, and the clinical presentation of the disease is predicted to be severe, as characterized by early mortality or substantial impairment of basic function; and
  • transferring only male embryos for gestation to avoid introducing heritable genetic modification during initial clinical investigations.

Following successful initial investigations of MRT in males, the committee recommends that FDA could consider extending MRT research to include the transfer of female embryos if clear evidence of safety and efficacy from male cohorts, using identical MRT procedures, were available, regardless of how long it took to collect this evidence; preclinical research in animals had shown evidence of intergenerational safety and efficacy; and FDA’s decisions were consistent with the outcomes of public and scientific deliberations to establish a shared framework concerning the acceptability of and moral limits on heritable genetic modification.

The research in this area is interesting and our ability to help achieve healthy lives continues to grow. The path to a bright future though is not without risk. It requires careful action to pursue breakthrough improvements while minimizing the risks we take to achieve better lives for us all.

Unexpected Risks Found In Editing Genes To Prevent Inherited Disorders

Earlier this month, a study published in Nature by Shoukhrat Mitalipov, head of the Center for Embryonic Cell and Gene Therapy at the Oregon Health and Science University in Portland, suggested that in roughly 15 percent of cases, the mitochondrial replacement could fail and allow fatal defects to return, or even increase a child’s vulnerability to new ailments.

The findings confirmed the suspicions of many researchers, and the conclusions drawn by Mitalipov and his team were unequivocal: The potential for conflicts between transplanted and original mitochondrial genomes is real, and more sophisticated matching of donor and recipient eggs — pairing mothers whose mitochondria share genetic similarities, for example — is needed to avoid potential tragedies.

“This study shows the potential as well as the risks of gene therapy in the germline,” Mitalipov says. This is especially true of mitochondria, because its genomes are so different than the genomes in the nucleus of cells. Slight variations between mitochondrial genomes, he adds, “turn out to matter a great deal.”

Related: Gene Duplication and EvolutionThe Challenge of Protecting Us from Evolving Bacterial ThreatsOne Species’ Genome Discovered Inside Another’s (2007)Looking Inside Living Cells

Eating Nuts May Reduce the Risk of Heart Disease, Cancer and Other Diseases

A large analysis of current research shows that people who eat at least 20g of nuts a day have a lower risk of heart disease, cancer and other diseases. The analysis of all current studies on nut consumption and disease risk has revealed that 20g a day – equivalent to a handful – can cut people’s risk of coronary heart disease by nearly 30%, their risk of cancer by 15%, and their risk of premature death by 22%.

While this is reassuring news to those of us (like me) that frequently eat nuts I am not sold on their evidence. Heath research is prone to overstating the benefits. Still there is little reason to avoid making nuts part of a healthy diet. That is a big part of the reason I have. They offer benefits and maybe even great ones (as indicated in this research) without much risk.

An average of at least 20g of nut consumption was also associated with a reduced risk of dying from respiratory disease by about a half, and diabetes by nearly 40 percent, although the researchers note that there is less data about these diseases in relation to nut consumption.

The study, led by researchers from Imperial College London and the Norwegian University of Science and Technology, is published in the journal BMC Medicine, Nut consumption and risk of cardiovascular disease, total cancer, all-cause and cause-specific mortality: a systematic review and dose-response meta-analysis of prospective studies (open access paper).

The research team analysed 29 published studies from around the world that involved up to 819,000 participants, including more than 12,000 cases of coronary heart disease, 9,000 cases of stroke, 18,000 cases of cardiovascular disease and cancer, and more than 85,000 deaths.

While there was some variation between the populations that were studied, such as between men and women, people living in different regions, or people with different risk factors, the researchers found that nut consumption was associated with a reduction in disease risk across most of them.

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Chimpanzees Solving Numerical Memory Test Better Than People

I can’t even see all the numbers before they disappear. But chimpanzees are shown seeing a flash of 9 numbers on a screen and then pointing to where they were on the screen in order from 1 to 9. Human test subjects can’t even do 5 numbers most of the time.

Related: Chimpanzees Use Spears to Hunt Bush BabiesOrangutan Attempts to Hunt Fish with SpearCrows can Perform as Well as 7 to 10-year-olds on cause-and-effect Water Displacement TasksTropical Lizards Can Solve Novel Problems and Remember the Solutions

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The Challenge of Protecting Us from Evolving Bacterial Threats

I have long been concerned about the practices we continue to use increasing the risks of “superbugs.” I have written about this many times, including: The Overuse of Antibiotics Carries Large Long Term Risks (2005)Are you ready for a world without antibiotics? (2010), Antibiotics Breed Superbugs Faster Than Expected (2010), Entirely New Antibiotic (platensimycin) Developed (2006), Our Poor Antibiotic Practices Have Sped the Evolution of Resistance to Our Last-Resort Antibiotic (2015).

I do also believe the wonderful breakthroughs we make when we invest in science and engineering have made our lives much better and have the potential to continue to do so in many ways, including in dealing with the risks of superbugs. But this is something that requires great effort by many smart people and a great deal of money. It will only happen if we put in the effort.

Winning war against ‘superbugs’

hey won this particular battle, or at least gained some critical intelligence, not by designing a new antibiotic, but by interfering with the metabolism of the bacterial “bugs” — E. coli in this case — and rendering them weaker in the face of existing antibiotics

ROS, or “reactive oxygen species,” include molecules like superoxide and hydrogen peroxide that are natural byproducts of normal metabolic activity. Bacteria usually cope just fine with them, but too many can cause serious damage or even kill the cell. In fact, Collins’ team revealed a few years ago the true antibiotic modus operandi: they kill bacteria in part by ramping up ROS production.

We need to continue to pursue many paths to protecting us from rapidly evolving bacterial risks. Many promising research results will fail to produce usable solutions. We need to try many promising ideas to find useful tools and strategies to protect human health.

US Fish and Wildlife Service Plans to Use Drones to Drop Vaccine Treats to Save Ferrets

Despite significant recovery successes, the black-footed ferret remains one of the most endangered animals in the world.

Black-footed ferret

Black-footed ferret, photo by J. Michael Lockhart, USFWS.

The U.S. Fish and Wildlife Service has developed a plan to use (UAS) to deliver prairie dog sylvatic plague vaccination.

The primary purpose in this proposal is to develop the equipment, protocols and experience in use of UAS (drones) to deliver oral sylvatic plague vaccine (SPV). It is anticipated that this approach, when fully developed, will offer the most efficient, effective, cost-conscious and environmentally friendly method to apply SPV annually over large areas of prairie dog colonies in support of black-footed ferret recovery.

Plague is a primary obstacle to black-footed ferret recovery. After more than 20 years of intensive reintroduction efforts across 27 reintroduction sites ranging from Mexico to Canada, approximately 300 ferrets were known to exist in the wild at the end of 2015. Ferrets are constantly threatened by plague outbreaks that affect both ferrets, and their primary prey and habitat provider, prairie dogs.

To date, SPV has been applied by hand with people walking pre-defined transects and uniformly dropping single SPV baits every 9-10 meters to achieve a deposition rate of 50 SPV doses per acre. Depending on vegetation and terrain, a single person walking can treat 3-6 acres per hour. All terrain vehicles (ATVs) have been considered but have various problems.

The bait treats are M&Ms smeared in vaccine-laden peanut butter.

Preliminary discussions with people experienced with UAS suggest an aerial vehicle travelling at a modest 9 meters per second could drop a single SPV bait once per second that would result in treating one acre every 50 seconds. If the equipment and expertise can be developed as proposed here, a single UAS operator could treat more than 60 acres per hour.

If the equipment can be developed to deposit 3 SPV doses simultaneously every second, as they envision is possible, some 200 acres per hour could be treated by a single operator. The idea is that the drone would fire the treats in 3 different directions to increase the spread of treats.

The areas to be treated are located in South Phillips County, Montana.

Related: Using Drones to Deliver Medical Supplies in Roadless Areas (2014)The sub-$1,000 unpiloted aerial vehicles UAV Project (2007)Autonomous Flying Vehicles (2006)Cat Allergy Vaccine Created (2011)AlienFly RC Mosquito Helicopter (2007)

Dinosaur Bird Wing and Feather in Amber

Rare Dinosaur-Era Bird Wings Found Trapped in Amber

Two tiny wings entombed in amber reveal that plumage (the layering, patterning, coloring, and arrangement of feathers) seen in birds today already existed in at least some of their predecessors nearly a hundred million years ago.

Skin, muscle, claws, and feather shafts are visible, along with the remains of rows of feathers similar in arrangement and microstructure to modern birds.

photo of dinosaur wing in amber with feathers visible

The nearly 100 million year old wing shows a structure that is very similar to modern birds.

The piece in this photo, and others samples, were bought at an amber market in Myitkyina, the capital of Kachin state in northern Myanmar. The region is politically unstable and most of the amber is sold to Chinese consumers for jewelry and decorative carvings.

Read the related posts for more on the wonderful discoveries saved in amber of hundreds of millions of years. We get to read about these amazing discoveries so often it is easy to lose appreciation for how amazing each one is. This photo shows a wind that was used by a dinosaur almost 100 million years ago.

Related: Marine Plankton From 100 Million Years Ago Found in Amber 2008)Learning About Life over 200 Million Years Ago From Samples Trapped In Amber (2012)The evolution of birds from small predatory dinosaursDino-Era Feathers Found Encased in Amber (2008)Amber Pieces Containing Remains from Dinosaurs and Birds Show Feather Evolution (2011)Ancient Whale Uncovered in Egyptian Desert

An Eukaryote that Completely Lacks Mitochondria

If you don’t have any idea what the title means that is ok. I probably wouldn’t have until the last 15 years when I found how interesting biology is thanks to the internet and wonderful resources online making biology interesting. I hope you find learning about biology as interesting as I do.

Look, Ma! No Mitochondria

Mitochondria have their own DNA, and scientists believe they were once free-living bacteria that got engulfed by primitive, ancient cells that were evolving to become the complex life forms we know and love today.

What they learned is that instead of relying on mitochondria to assemble iron-sulfur clusters, these cells use a different kind of machinery. And it looks like they acquired it from bacteria.

The researchers say this is the first example of any eukaryote that completely lacks mitochondria.

However, the results do not negate the idea that the acquisition of a mitochondrion was an important and perhaps defining event in the evolution of eukaryotic cells, he adds.

That’s because it seems clear that this organism’s ancestors had mitochondria that were then lost after the cells acquired their non-mitochondrial system for making iron-sulfur clusters.

Biology is amazing and mitochondria are one of the many amazing details. I wish so much that my education could have given biology a tiny fraction of the interest I have found it in after school.

Related: Human Gene Origins: 37% Bacterial, 35% Animal, 28% EukaryoticOne Species’ Genome Discovered Inside Another’sParasite Evolved from Cnidarians (Jellyfish etc.)Plants, Unikonts, Excavates and SARs

Healthy Living Greatly Reduces Likelihood of Dying from Cancer

Lifestyle choices can greatly reduce the incidence and death rates from cancer. 4 factors can reduce the incidence of cancer by up to 40% and death rate by 50%: don’t smoke, don’t drink alcohol in excess, maintain a BMI between 18.5 and 27.5, and exercising at a moderate intensity for at least 150 minutes or at a vigorous intensity for at least 75 minutes every week.

Preventable Incidence and Mortality of Carcinoma Associated With Lifestyle Factors Among White Adults in the United States

A substantial cancer burden may be prevented through lifestyle modification. Primary prevention should remain a priority for cancer control.

Cancer is the second leading cause of death in the United States, with 1.6 million new cancer cases and 0.6 million cancer deaths projected to occur in 2016.1 The cancer mortality rate, age-standardized to the 2000 US standard population, decreased from 199 to 163 per 100 000 between 1969 and 2013.2 However, this decline (17.9%) has been modest compared with the dramatic decrease in heart disease mortality (67.5%) during the same period, highlighting the need for further efforts in cancer prevention and treatment.

The study reviewed previous studies and the makeup of the previous studies and available statistics. As they state in the paper: “Because our cohorts’ participants were predominantly whites, to avoid any influence of different racial distributions on the comparison with the general population, we only included whites in the analysis.” They also excluded about 10% of cancers that are believed to have strong environmental factors.

Table Showing a Comparison of Lifestyle Factors in the Low- and High-Risk Groups

In the 2 cohort studies of US white individuals, we found that overall, 20% to 40% of carcinoma cases and about half of carcinoma deaths can be potentially prevented through lifestyle modification. Not surprisingly, these figures increased to 40% to 70% when assessed with regard to the broader US population of whites, which has a much worse lifestyle pattern than our cohorts.

Notably, approximately 80% to 90% of lung cancer deaths could be avoided if Americans adopted the lifestyle of the low-risk group, mainly by quitting smoking. For other cancers, from 10% to 70% of deaths could be prevented. These results provide strong support for the importance of environmental factors in cancer risk and reinforce the enormous potential of primary prevention for cancer control.

Related: A Healthy Lifestyle is More About Health Care than the Sickness Management That We Call Health Care IsBetter Health Through: Exercise, Not Smoking, Low Weight, Healthy Diet and Low Alcohol Intake (2013)Exercise Is Really Really Good for YouPhysical Activity for Adults: Inactivity Leads to 5.3 Million Early Deaths a Year (2012)

Medicinal Plants

Another great webcast from SciShow. In this webcast Hank Green discusses how we have used plants to treat us and improve our health.

In the webcast, Hank also does a good job touching a bit on the scientific inquiry process (which is something I find interesting and I think is very important for people living in society today to understand).

Related: Youyou Tu, The First Chinese Woman to Win a Nobel PrizeRubber TreesPhotosynthesis: Science Explained

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