Erroneous Blooming in Autumn or Winter

When Nature Makes Mistakes 

Spring plants flowering in autumn; dragonflies laying their eggs on the tarmac of an asphalt road (which on account of its reflected polarized light they mistake for a freshwater stream); bulls used for breeding and artificial insemination ejaculating into a tube held by a collector inside a dummy model cow that the sex-starved bull mounts; the greedy toad consuming a Ramphotyphlops braminus “blind snake” that after having survived the passage through the toad’s digestive system wriggles out of the toad’s anus alive; the false or so-called “pseudo-pregnancies” relatively common in feral and wild dogs: are they (and many others like them) not examples of the fact that mistakes abound in Nature and Nature isn’t perfect? I suppose not to be 100% perfect is the difference to “cold” mathematics and, thus, the charm of Nature (and perhaps of some of our loving partners, too).

But what about plants that usually flower in spring, but suddenly produce some blossoms in autumn or winter? I’ve seen that as a child with plums and other trees and yet again here in South Korea with plants that were in full bloom during spring, but now in late autumn or early winter sport an isolated and lonely flower on their branches. Insects that could pollinate such flowers are mostly no longer present and it would be too late for a fruit to ripen let alone develop. What goes on and how can Nature allow this to happen; something which must be a waste in view of the plant’s survival strategy for winter. Actually, many plants that flower in early spring, and this includes plum and apple trees, already form their buds during the preceding summer. When the next spring arrives, the buds open. It’s the period between the formation of the buds and when they open, which is the key to understand why mistakes occur. It seems that weather conditions are erroneously interpreted by plants that allow their buds to open prematurely in autumn so that they can have a ‘head start’.

Winter dormancy for the vast majority of plants represents a period of stress: short days with little sunshine, reduced precipitation and then often only in the form a snow, low temperatures and low humidity. Under such conditions, it is best for plants to ‘slow down’ and get ready for better times to come. For some very ‘impatient’ plants such seemingly better times appear to have come when after a short spell of very dry and cold nights, perhaps in combination with a period of dry weather before the cold spell, suddenly temperatures rise again for a few days, the sun shines and moisture enters the soil. It gives these most impatient plants the signal to “go for it” and quickly open their flowers before the competition gets ready. However, it’s a stark mistake and the only beneficiary may be some of the few late-flying and cold-hardy insects still around. But why are there a few insects at all?

The reason is not the presence of the occasional autumn flower of a species that would normally erupt in inflorescences during spring; it is because there is a small number of plant species that always and naturally produce their flowers in autumn or early winter. Some of the plants that flower in late autumn, mid winter or early spring include the Mahonia tree, snowdrops and bluebells as well as some pansies, Hellebore and Grevillea species. For them the advantage is that they can have the very few pollinators still (or already) around, such as bumble bees, some moths and certain flies, to themselves. It’s similar to one take-away shop still open at night when all the others are already closed. The few customers still around at night will all shop at those very few places that are still open at that time. Are plants with wrong flowers in autumn then bad ‘thinkers’? Well, “errare  humanum est”  (-not only, it seems).

© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2021. Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to V.B Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com with appropriate and specific direction to the original content.

Viruses

A Story of “Dead and Alive”

I think very, very few people enjoy viruses (maybe Dr Fauci, but he too seems to have had a problem to advise the public decisively how to deal with them). So, what are they? Tiny, balloons that swirl around in the air, waiting to be inhaled to make us sick? No, that’s wrong. Are they perhaps the microscopic cells like bacteria you can’t see? No, that’s wrong too. Are they in fact living organisms at all? No, that’s also wrong. Well, they’ve got to be dead things then. But that, too, ain’t right. So, what are they really?

When as a 13-year old I got a new biology teacher, he taught us boys that viruses were neither alive nor dead, but consisted of ribonucleic acid (RNA), which contained genetic information to make more viruses. But a virus does not have the cellular equipment to follow up the instructions of its genetic code on the RNA, but needs to hijack a living cell to do that job for it. Bacteriophages let bacteria do that job, but other kinds of viruses seek the help of multicellular plants or animals. So, a virus on its own, according to the information given to us pupils in 1958, was not considered a living organism, but a complicated molecule that usurped a living cell to start producing more viruses instead of the proteins needed by the organisms the cell was a part of. This was so alien an information to my understanding (and love) of Biology at that time, that I “switched off” and ended up that year receiving the worst grade in Biology one could get. However, let this be an encouragement to all pupils and students, who receive low grades: my lousy grade did not kill my interest in Biology; it may have shifted it a bit towards math and other sciences, but a year later I had the highest grade in Biology again. But now back to the viruses.

How much has actually changed as to whether a virus is alive or dead? Not much, it seems, although some progress has been made. In the current scientific literature, one can come across the view that viruses cannot be regarded as ‘living’. Viruses do possess RNA (and some contain DNA), but they lack a cell membrane or cell wall; they do not possess ribosomes (like our teacher said in 1958: they lack the machinery to synthesize proteins); viruses have no metabolism, they do not respond to stimuli, and they cannot reproduce themselves. However, if the concept of a ”cell” is the criterion to decide whether something is alive or dead, then one could argue, that a virus is at least “alive” when it is inside a host cell and the virus’ genes are “instructing” the host cell what to produce from then on (namely, more viruses). The hijacked cell becomes the “virus’ home”, essentially a “the virus’ cell”! This concept is supported by microbiologists, who point out that chloroplasts and mitochondria (both integral parts of living cells) once existed as independent entities, before taking up permanent residence in “proper” cells.

Horizontal gene transfer is mentioned as an argument that one cannot exclude viruses from the “tree of life”, because viruses were (and still are) involved in transporting genes from cells of one organism to cells of another, jumping the “species barrier” and thereby contributing to the evolution of different species’ characters. Viruses affect all forms and branches of life and must have been around with the earliest of the cellular organism. Is it possible that viruses broke away from cellular genes and escaped, so-to-speak, from proper cells, only to adopt a parasitic ”mode of life”? This is one of several theories of how viruses could have arisen. Maybe one should call the inactive, extracellular state a “virion” and the active intracellular state “a virus cell”. That was a suggestion made in 2021 by the Irish scientists H.M.B. Harris and C. Hill. Does that solve the impasse? To some extent I think it does, but suddenly viroids come to my mind (and they are not exactly viruses) and how about the virus-like agents, known as prions, mad-cow-disease, kuru, and the frequent mutations of the viral RNA or DNA ….?  No, it ain’t easy at all.

© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2021. Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to V.B Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com with appropriate and specific direction to the original content.

Ionising Radiation Can Kill

But not everyone equally

Everybody knows that an exposure to ionising radiation can be lethal, can cause mutations and abnormal offspring, or may result in developing a tumour, in other words leading to cancers. Nobody would also be surprised to hear that the champion survivors of extreme conditions (when in a state of “cryptobiotic anhydrosis”), like some unicellular algae and bacteria and, of course, the “radiation-loving” fungi found growing in the burnt out remains of the Chernobyl nuclear reactor, can tolerate high doses of radiation. But that there were no statistically significant increases of abnormalities amongst the children of the survivors of the Hiroshima nuclear bomb explosion or the Chernobyl disaster and that among larger animals desert scorpions like Androctonus survive an X-ray exposure of 100,000 Roentgen, while humans or dogs cannot tolerate doses higher than 500 and 350 R, respectively, may be news to many.

But what is it in the first place that makes ionising rays, which are also electromagnetic waves like infrared, visible and ultraviolet light, so dangerous? These forms of electromagnetic radiation due to their higher energy content are increasingly more powerful as their wavelengths decrease and their frequencies increase. X-rays, being shorter than UV and visible light, are ionising, but gamma (γ) and alpha rays (α), the latter two emitted from radioactive elements, are more powerful; neutrons and cosmic rays are the most damaging. When the ionising rays hit living tissue, they cause molecular alterations, leading to the production of “free radicals” that injure and break chemical bonds to create more radicals (like Dr Eguchi and I showed in crayfish following exposures to UV radiation). Ionising rays can damage the DNA of cells, influence cell divisions and produce rapidly dividing tumour cells. The latter characteristic, however, is used in cancer treatments with ionising rays focused on the tumour cells that owing to their rapid proliferation cannot fast enough activate the necessary repairs.  

In humans, if an exposure to the ionising radiation hasn’t led to a rapid death, the effects more or less follow this sequence: nausea, loss of appetite, diarrhoea, fever, haemorrhaging, hair loss, infections and skin lesions; leukaemia (due to damaged bone marrow) is one of the feared consequences of radiation exposure. However, the body’s repair “machinery” is amazing, for within a few hours 60% of the radiation damage will be repaired. It does, of course, depend on the amount and duration of an exposure and a somewhat higher but shorter exposure may be less damaging than a lower but much longer exposure. And where do the ionising rays that could harm us and all living things on Earth come from? There are of course the radioactive elements and their minerals, the radioactive gas radon, X-rays and radiation from K40 and C14 isotopes in living cells. But most powerful would be the cosmic rays that are largely diverted by the Earth’s magnetic field and held in the Van Allen Belt. When, however, the magnetosphere collapses and North and South poles change (which has happened repeatedly in the Earth’s history), all creatures become exposed to cosmic rays. And that perhaps is one explanation why the scorpions whose ancestors were around already 400 million years ago and weathered numerous North/South flips of the magnetic field are so radiation tolerant. There are numerous units like Roentgen (R), rad, rem, Gray (gy), Sievert (Sv), and Becquerel (Bq) in use to describe radiation strengths and effects. But irrespective of the unit we use in connection with them, regarding scorpions like Androctonus (see below), whose radiation tolerance was measured by the French scientists P. Niaussat, M. Vachon and co-workers during the era of nuclear bomb tests after World War II, they are tough and perhaps the toughest of all multicellular animals larger than tardigrades (although some insects are also pretty resistant). The relatively small amount of water in their bodies and, in case of the scorpions, a possible relation between their high radio-resistance and their low nucleic acid concentration was discussed. When I wanted to get a PhD-student interested in testing radiation damage in different animals and plants (cabbages, for example), he was worried and not interested in the topic. Well, I suppose I couldn’t blame him.

© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2021. Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to V.B Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com with appropriate and specific direction to the original content.