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| Life On Earth (from The Quick Guide To Creepy-Crawlies) |
Some of you may have noticed that there is a bit of a bug going around at the moment. It's OK, I'm not going to bang on about coronovirus, which you're all fed up to the back teeth reading about, but to have a more general look at the world of bacteria and viruses and try to answer the question, “what have they ever done for us?” The figure on the left (taken from my book The Quick Guide to Creepy-Crawlies) shows how life on Earth is classified into three sections (called Domains). All of the animals and plants that you can see with the naked eye (and many too small to see) fit into the bottom section, the Eukaryotes. The microscopic bacteria and the archaea between them, form a group called the Prokaryotes.
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| bacteria colonies on beetroot |
Let's
look at bacteria first. You're probably familiar with many of them:
Escherichia
coli (E. coli in
common parlance), discovered by Theodore Escher in 1884 and the bane
of butchers ever since; Staphylococcus
aureus, the
SA in MRSA that bedevils hospitals (the MR being multi-resistant [to
antibiotics]); and Streptococcus
pyogenes,
the 'strep' in strep throat. But not all bacteria are bad. In fact,
we couldn't live without them, they synthesize all the Vitamin
B12
in
the world for a start. They are responsible for the breakdown of
organic material that returns nutrients to the soil, as these colonies
of bacteria are doing to this beetroot.There are also an awful lot of
them: between them, they weigh more than every animal and plant on the
planet combined.
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| Archaea providing a splash of colour |
The
other half of the Prokaryotes are the archaea, with which you are
probably not so familiar. These differ from bacteria (and ourselves
for that matter) in their cell structure and basically, they are good
guys. For instance, we couldn't digest our food without the help of
an archaean with the zippy name of Methanobrevibacter
smithii. When
our gut bacteria have finished breaking down our meat and three veg.
into stuff we can actually use to keep us alive, M.
smithii mops
up the bits that are left behind. They also bring a little colour
into our lives as this picture of the of
the Morning Glory Hot
Spring
in
Yellowstone
National Park,
taken by ZYjacklin
shows. The archaea are responsible for the bright yellow around the
rim of the spring.
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| Coronavirus (Alissa Eckert, MS; Dan Higgins, MAM / Public domain) |
So,
where do viruses fit into all this? Awkwadly. Some say that they are
a form of life (because they have genes and can reproduce) and some
say that they are not (because they lack a cell structure).
Personally, I go with Dr. Spock - “It's life Jim, but not as we
know it.” They only come alive and reproduce when they are inside a
host organism (plant, animal, bacteria or archaea), at all other
times they exist as bits of genetic material in a protein coat
floating about like teenagers looking for a party to crash. To
continue the analogy, once they've found a party to crash, they trash
the place by imparting a disease to the host (the SARS-CoV-2
virus currently spreading the COVID-19
disease around the world for example). They then move on to the next
party through a variety of means; insects ferry them from plant to
plant like Uber drivers; 'coughs and sneezes spread diseases' is an
old adage which was made for them; poor toilet hygene (in the case of
norovirus and rotavirus); or through intimate contact (such as HIV).
Whether you consider them as living entities or not, Earth wouldn't
be the same without them as they are the most numerous form of
'biological entity' on the planet. But what use are they?
Viruses
spread most quickly when there is a high density of host organisms in
one place and where there is a method of transportation between
different groups of populations. This occurs most often when the
population growth of a species spirals out of control. So, maybe we
should consider viruses as nature's population control mechanism. A
bit like brakes on a car; they don't make the car go any better,
further or faster but they are a very necessary part of the over all
design.
Talking
of life, but not as we know it: I have a new novella out this week
entitled The Eggs of Saramova which starts here in Greece and then
moves somewhere further afield. It's a fast paced thriller, only
available on Kindle at the moment (the paperback will be published in
time for the summer) and you can read the first couple of chapters
for free (or the whole book if you're enrolled with KDP Select) by
following this link: http://viewbook.at/Saramova
Steve's Books
The
Eggs of Saramova
A
science fiction novella for those who don't like science fiction.
A fast-paced thriller that is, literally, out of this world (and
it starts right here in Crete).
All
you need to know to identify any type of insect, spider, worm or
snail very simply and find out more about it.
A
light-hearted look at life through the eyes of the fairer sex.
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See sample pages of all my books and latest blogs and keep
abreast of latest publications here: http://author.to/SteveDaniels |
Crete
Nature Catch-up
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Antibiotics fight bacterial infections either by killing bacteria or slowing and suspending its growth. They do this by: attacking the wall or coating surrounding bacteria. Interfering with bacteria reproduction.
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