Download Some Evolutionary Basics

Jan Madsen AB
Some Evolutionary Basics
Since our evolved behavioral dispositions are still with us today,
it pays to understand how evolution works!
Evolutionary topics are on the rise! TV documentaries, books, magazines and articles are
popping up offering evolutionary explanations as
to why people behave the ways they do. This is
due in large part to a number of great discoveries
in the past fifty years concerning the evolution of
human behavior.
Unfortunately, most readers and viewers don’t
know enough basics about evolution - and don’t
bother to learn them - to fully understand the
information. They too often misinterpret this
information and thus get a distorted view of evolutionary theory.
Our experience is that when people are asked if
they understand evolution, most return a reflexive response: “Yeah, yeah, I know evolution so
go on I will understand what you are saying”.
But when asked to explain how it works, some
get quiet and hesitant, realizing that they actually
don’t know, while others respond with a dead
sure statement that they think explains it all, such
as: “Yeah, I know, survival of the fittest! The
strongest survive and the weak die out, end of
story.”
Such a statement only reveals that they are not
even aware that there is a lot more to the survival process than strength.
By just adding some basic knowledge, much
more information is understood, and most
importantly, the risk of misinterpretation is reduced. When you understand the basic principles,
you understand how the process has shaped many
universal behaviors that still affect us today,
such as how we compete, cooperate, feel jealous or earn good reputations.
You are also rewarded with an interesting perspective on yourself, the people around you and
life in general. And it doesn’t take longer than
it takes to read this paper to get the basics. Time
well spent considering how central this process
is to who we are and how we think and behave
today!
Here follows the minimum that you need to
know to understand how evolution works,
followed by some interesting topics and common misconceptions.
How evolution works
First you need to know that the most important
mechanism of evolution is Natural Selection.
Natural selection is a process that discriminates
between what works and what doesn’t work when
it comes to traits that confer differential success in survival and reproduction between individuals.
Success depends on how well an individual organism’s traits and behaviors are suited to the
environment in which that individual must survive and reproduce.
In other words, those that are sufficiently
adapted to their environment, commonly called
the “fittest”, will do better on balance and leave
1 more offspring. This “fitness” is often misinterpreted as strength, but fitness means a general
suited-ness to the environment. Strength may be
one possible road to fitness, but it may not always be the best.
Natural selection is never moody, never subjective and never ever forgiving; it will always
discriminate between what works and
what doesn’t. If not good enough, a single
trait/behavior or an entire species will eventually
go extinct. If good enough, the trait/behavior
survives and is replicated into another generation.
But not everything can evolve. For natural selection to kick in the following has to occur:
1. There are more offspring born than can survive and reproduce.
2. There is competition between these individuals for survival (food, shelter, health etc.) and
reproduction (sexual partners, fertility etc.)
they will tend to produce more viable offspring (offspring that survive to have offspring of their own) than others less suited.
Natural selection will favor these individuals until the conditions change and demand
other traits and abilities. The dinosaurs did
very well during the Mesozoic era until the
hypothesized asteroid impact, which opened
up an opportunity for the mammals, like us,
and we will go on until changes in the environment combined with a lack of suitable
variations put an end to our existence.
6. Heredity is another vital ingredient of evolution. Variations would not matter to evolution if they could not be inherited by the
offspring. After variations are inherited, then
the process of natural selection begins again
for the next generation. The offspring who
inherited the best traits will go on to leave
more offspring of their own, who will carry
those traits another generation into the future.
3. There must be variation between individuals.
Variations can be seen in anything from leg
length to lung volume to immune system
strength to attractiveness to intelligence.
These six demands for evolution can be reduced
to three demands that the philosopher Daniel
Dennett collectively calls The Evolutionary Algorithm:
4. The variations, often resulting from genetic recombination and mutations and results in
individuals doing better or worse. Variation is
a vital ingredient for evolution because it is
that which causes differential survival and reproductive success. If all individuals in a population are completely alike (i.e., there is no
variation be- tween them), then the population cannot evolve (unless, of course, variation is introduced from outside). The population can live on for a very long time, generation after generation, but it will most likely
suffer or even go extinct as soon as the environment changes. No variation à No evolution!
Variation
+ Selection
+ Heredity
5. Natural Selection will favor those who
are better adapted to the environment, for
= EVOLUTION
If they coexist, then evolution will happen.
Three interesting aspects of evolution
Sexual Selection
There is an interesting and very important sub
category of Natural Selection that is greatly
affecting our lives: Sexual Selection.
Because reproduction is important for evolution, behaviors relating to how we make ourselves attractive as sexual candidates and how
we compete to mate with the best candidates
2 has its own name: simply, sexual selection!
When we talk about survival in evolutionary
terms, we are mostly interested in reproductive
success, not how long an individual lives.
Therefore, choosing a mate or making sure
oneself will be chosen as a mate is of utmost
importance, and sexual selection has greatly
shaped male and female bodies and behaviors
to suit reproductive demands and competition.
More information about how sexual selection
works can be read in the article “The not-sopolitically-correct story of Anisogamy”.
Universal traits
Evolution has resulted in many universal traits.
Since all humans are descendants of a small
group of people who lived, evolved, increased in
population and spread out during 1.8 million
years within the period called the Pleistocene,
they developed a suite of universal characteristics
still seen in all or most humans today.
Even though agriculture and industrialization,
different regions and religions, diverse cultures
and other environmental and social changes have
made groups and individuals display different
traits and customs, the evolved universals are
still in us. Within all human groups people
laugh, cry, cooperate, cheat, learn to talk and
fall in love similarly to other human beings.
It is wise to remind ourselves about those universals and make good use of them. For one,
focusing on universals instead of differences can
help people connect despite seemingly clashing
cultures.
Mismatches
We evolved to a life in the past much different
than that of today. Today’s society is changing
too fast for evolution to keep up so our evolved
universals and specific adaptations sometimes
clash with contemporary life, resulting in maladaptive behavioral responses.
A simple example is our great appetite for
sweets and fats that evolved long ago. We
adapted to look for such rare and valuable
sources of energy and eat all we could when
the opportunity arose because it greatly helped
us survive.
But today, sugars and fats are now superabundant in industrialized countries, and there has
not been enough time to evolve an appropriate
curb in our appetite that balance this new environment. The mismatch, the adaptation coupled
with availability, results in obesity, hypertension and other health issues.
Other examples of mismatches are the difficulties we have when learning, remembering and
applying math, statistics and logic, since the
demands for those were different in the far past.
Since mismatches can explain counterproductive
behaviors and difficulties in learning things for
which we’re not adapted, it’s an area where we
places much interest.
Some common misunderstandings about
evolution:
“Evolution is not a science, because
it is not observable or testable”
Wrong! Evolution is observable and testable.
Some still think that science can only be carried
out by people wearing white coats working in
laboratories that smell of white mice.
But, the science of evolution is carried out more
like solving a puzzle, where logical reasoning
about what must be true and what cannot be
true is done with the assistance of evidence
from such different sources such as archaeology, biology, chemistry and biological anthropology, to mention just a few.
Ask yourself how you can deduce that the
earth is round, for it is also like a puzzle, since
you cannot place the earth under a microscope
or even hold it in your hand. Instead, you have
to get a picture from a satellite, measure the
3 bend on the horizon and, in the end, logically
reason towards the conclusion that, yes indeed,
the world is round!
“Evolution doesn’t affect us anymore
since we have stopped evolving!”
This is debated, but strictly speaking, evolution
happens if you have variation, selection and heredity, and we still have those. Individual variations still arise and despite, or because of, modern medicine and technology, there is differential survival and reproductive success between
people and their genes. When humans are
spread out across different environments, different groups will develop their own unique
adaptations.
Take for example the ability of adults to produce lactase. Lactase production, needed to
digest lactose in milk, usually stops during the
juvenile period, but in populations that milked
animals, some had an adaptation for digesting
milk and this was inherited and spread
throughout the group. In populations where
milking has not been common, the prevalence of
lactose intolerance is high.
Even if we stopped evolving, the mismatches
would prevail.
Don’t get caught in what is called
the Nature versus Nurture Debate!
In this polarized and ultimately futile debate it is
argued that what explains behavior is either
nature OR nurture. Anybody who will try to
persuade you that all behaviors can be explained solely by genetics or solely by culture
has missed the point. Nature (often referring to
genetics) and nurture (often referring to the
environment or culture) are closely intermingling.
However, there is no doubt that nature preceded culture and continuously shapes it. But
culture can also shape nature, as when subsist-
ence milking of animals places a pressure on
the selection for lactose tolerant mutations.
“Evolution has a set direction since
things always evolve for the better
and things are always progressing.”
Absolutely not! It is true that Natural Selection is
a grim reaper for that which does not work, but
first, it is important to know that “good enough”
is good enough for survival and reproduction. A
perfect survivor and reproducer is a rare thing,
and most organisms are far from perfect. Second,
remember that because of random mutations and
changing environments, what is surviving and
reproducing today might not tomorrow, so a
steady progressive climb is not a common result. Keep in mind that adaptations are linked to
environment, not to progress.
“Evolution is all due to chance!”
Partly wrong! Randomness is a factor in the evolutionary process, since mutations are thought to
be random. But when you take into consideration how non-random Natural Selection is when
it determines what stays and what goes, you
understand that survival and reproduction is not
just due to chance. Since only certain traits can
evolve within certain environments, the selective process of evolution is specific and not
random.
This article presented some of the evolutionary
answers to why, how and with whom we should
cooperate. By understanding how we are adapted
to collaborate and what mismatches we are facing, we can find good motivational strategies
that enhance cooperation naturally.
Helena Svensson
Copyright © 2015 Jan Madsen AB
www.janmadsen.eu
4