Modern Biology is dominated by molecular approaches and,
especially, the role of genes in evolution and in medicine. In
contrast, my degree studies in Zoology in the 1960s were based on the structure
and function of a wide range of whole organisms. However, we were introduced to
the importance of genes and the way that they interact with the environment (whether
within a single cell, within an individual, or outside an individual) through
the phenotype (the appearance created by gene expression). We learned that
changes in the genotype (the whole genetic makeup, also called the genome) that
occurred by chance mutations resulted in changes in the phenotype and that a changing
environment allowed the selection of different phenotypes (and thus genotypes)
that would be favoured. It is the process of natural selection that Darwin propounded,
with the addition of an explanation based on genetics. In the natural world,
the process whereby a genetic mutation results in a successful phenotype may
take thousands of years to spread through a population: much less in primitive
organisms with short, or very short, life cycles.
It was a relationship that always stuck in my mind, although
it had little influence on my research and teaching. Some of my research
collaborators worked on phenotypic plasticity (different environmental
conditions allowing the expression of different parts of the same genotype), so
I had that idea, and could see how it applied to animals such as the arctic
hare and the ptarmigan that change the colour of their coat/plumage from summer
to winter as their environment changed from multicoloured to white. This is
clearly under genetic control and requires changes in the physiology of each
animal, driven by the influence of environmental cues. There are many more examples
in the natural world.
The genotype-phenotype-environment relationship is of great
interest to humans, although we may not know of it as such. While recognising
that we are created by our genes, it is our phenotype that most interests us in
Western countries - the way we look. Of course, we add to that by changing our
external appearance frequently (unlike arctic hares and ptarmigans) by using
clothes and other coverings. Much attention is given to the hair that grows on
parts of our bodies and, recently, on body ornamentation in the form of tattoos.
However, it is our shape, and the appearance of different body parts, that most affects us, as these are not easily changed in hours.
Unfortunately, not everyone is satisfied by their body and
surgical procedures are used to change our phenotype. These include face lifts,
breast enlargement or reduction, hair transplants, modifying parts of the face
(like cheek bones and noses), and many others. Cosmetic surgery is invaluable
after accidents or major illness, but the modification of appearance for vanity
is narcissistic; yet so important to those that spend large sums of money on
these procedures. Recently, a contestant on Love Island, a reality TV show in the UK, admitted
to having extensive cosmetic interventions on various parts of her body; the
cost being estimated at £25,000. She stated “I didn’t take all the decisions
(about the operations, fillers, etc.) because I was trying to be a role model.
I did it for me and no-one else.” [1]. In the article (see above) she didn’t
explain why the results of the procedures made her feel better. The legendary
Jocelyn Wildenstein probably spent a lot more on her surgical enhancement (see
below) and she has stated that she is very pleased with the results, as she
always wanted to look like a large cat. I have no idea whether she knows that
others find her appearance monstrous.
In medicine, we are now looking to alter genotypes to
prevent serious illnesses, or as a means of treating existing ones, with the
exciting development of pharmacogenetics allowing drug treatments that are
tailored to individuals. Very large sums of money, and much effort, go into
this and the results in a few areas are highly promising. I wonder how long it
will be before changing our genotype becomes an acceptable way of altering our
phenotype and thus the way we look? It is unlikely to be soon, as so many genes
are involved, and it may only be effective during early development, when adult
features are beginning to form. Designer babies anyone?
At the opposite end of the age spectrum, we are also investing
heavily in studies of ageing. Genetic engineering based on the results of these
studies could promote an appearance of agelessness; replacing the cosmetics and
cosmetic procedures on which we spend so much money. Then, if we can reduce the
appearances of ageing, can we genetically engineer individuals to not age and
thus not die? Surely that will never happen?
So, what of the third factor in the genotype-phenotype-environment
relationship? We are mostly concerned with our social environment and, through
research, in the environment within individuals. Our progressive destruction of
the natural environment, a factor in both mental and physical health, might
make selection of the phenotypes from altered genotypes irrelevant. But then,
our interest is in humans, and the superficiality of humans, above all else.
[1] The i 2nd
August 2018
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