Many people assume that, because humans are the dominant species on planet Earth,
and because we control so much of what goes on in the world,
that we must have stopped evolving,
and are no longer subject to any form of natural selection.
Maybe people assume this because modern humans live very comfortable lives,
and unnatural death is becoming increasingly rare.
However, this idea is false.
Humans are very much still under the pressure of natural selection,
and to a certain extent, probably always will be.
First of all, one of the biggest errors people make
is that unnatural death is required for evolution to occur.
This is not true at all.
Evolution still proceeds even if unnatural death does not occur.
Evolution is a result of which individuals pass on their genes more than others.
It is often the case that a person decides not to have children,
and this can still be a strong evolutionary disadvantage,
even in modern times.
It can also be the case that a person dies unnaturally
after they have already had children,
and that may have little impact on their reproductive success.
Even if it were the case that all people had children,
this still does not impede evolution
because the quantity of offspring is still a very relevant factor.
A person with a single child will only pass on half of their genes,
while a person that has two children will pass on about an equal amount of their genes.
More so, a person with four children
will double the representation of their genes in a population.
Another factor that is often overlooked within human evolution
is the process by which human genes get passed on.
There are countless genes that are essential to the development of the human body.
If any one of these genes are removed,
that body can not develop.
If an essential gene becomes mutated,
that organism will not grow,
and will not pass on the negative mutation.
Even further,
human sperm are also still subject to the full spectrum of natural selection.
Only healthy, energetic sperm have an opportunity to reach and penetrate an egg cell.
If an immobile sperm were to develop,
it still has no opportunity to reach an egg cell,
and holds back any genes that caused the deformity
from reaching the next generation.
The opposite also holds true.
If a gene arose that allowed the sperm to reach an egg cell faster than its competitors,
then that gene would be more likely to be passed on.
Another misconception is that having more offspring is always an advantage,
and that having no offspring is an evolutionary dead end.
This is also not true,
since the vast majority of a persons genetics is not unique to that individual.
Even if an individual has no children,
the siblings of that individual still share about the same percentage of genes
as a child of that individual would.
If an individual can better the reproductive success of a family member,
this promotes their own genes as well.
This can be expanded even further, to large populations.
If one population that carries a certain set of genes grows faster
than another population that carries a different set of genes,
that will have an effect on the percentage of all genes.
This can even be seen in populations,
even regardless of weather or not the genes of that population are advantageous.
A good example of this is places like China,
that are major hubs of food production.
Because of the fertile farmland there,
and the efficient growth of the rice plant compared with other crops,
this has allowed the Chinese population
to grow faster than the surrounding populations,
even regardless of the genetics which that population carries.
It has also become a common belief that in the near future,
humans will simply genetically engineer themselves and their offspring,
removing natural selection from the equation.
It is true that genetic engineering could cause major differences in how humans will evolve,
however, this still does not remove natural selection from the equation entirely.
If free choice is present at all,
then not all individuals will desire the same traits.
This doesn’t eliminate natural selection,
but simply changes it.
Individuals that choose advantageous genes more accurately
will still be given an advantage,
while those that choose a poor set of genes will not.
Not all genes are compatible with each other,
and so, some planning would be required to produce the most successful offspring.
A person can not be the smartest,
and the prettiest, and the strongest,
all at the same time,
because many traits are not compatible with each other.
Specializing in one field,
often requires limiting yourself in a different field.
In order to produce successful offspring,
not only must the genes themselves be considered,
but also how compatible those genes are likely to be
with whatever they happen to be paired with.
If a certain gene is only an advantage
if it is paired with a gene that is not common in the population,
then that gene can actually be a disadvantage.
