“It’s just a theory”
is a chapter about the myths of evolution, which helps clarify the main topics
of the theory of evolution. Throughout years in public school education, teachers
have been required to teach the study of evolution as a theory. This approach
of evolution has failed in the classroom because of the different definitions
of theory. A theory can be considered a guess; however, when used by scientist the
word theory means it has been analyzed and supported justification for a selection
of facts. In order to establish a theory, a scientist follows a scientific
method approach. The scientific method approach contains an observation of an
object or procedure. They then create a hypothesis, which is an educated guess
of how the object or procedure works. Once the hypothesis is tested and
accepted the scientist publish a peer-review journal to share their findings. After
the hypothesis is repeated multiple times it is considered a theory. This
method can change depending on the scientist but the main components of them are
very similar to other methods.
The theory of evolution has
supporting information from many fields of study such as biology, ecology,
geology, and zoology. These supporting fields of study have helped in the
ability to present evolution as a fact and a scientific theory. Evolution is debated
that it is not a scientific theory because it cannot be studied in a laboratory
and it is information about the past. Scientist struggle with being able to
make a prediction about the past; however, predictions can be made from the
past because it is an observation or an educated guess of what has happened in
An opinion about evolution made by
Jean- Baptiste Lamarck is known as Lamarckism. Lamarck’s view of evolution was
composed of two principles. The first law is “use and disuse,” which means the
more you use a body part the stronger it will become and the less you use that
body part the weaker it will become. The
second law states “the inheritance of acquired characteristics,” which means
the stronger or fragile your body parts are will be passed to your offspring.
Lamarck’s ideas of evolution were wrong and have been replaced with the modern
The modern evolutionary theory
explains how characteristics are changed and transmitted over generations.
Evolution has three main components which include replication, variation, and
selection. Replication is reproduction, which can be asexual or sexual. Asexual
reproduction is an offspring from a single parent. Asexual reproduction is most
common in plants because the offspring will be identical to the parent. Sexual
reproduction is two parents combining their genes to create offspring. This
reproduction is most common in animals; however, some plants can sexual
reproduce through pollination.
Variation is differences between the
parents and the offspring. When the parents sexually reproduce the genes mix
and only certain cells unite together creating the offspring with those
characteristics. During variation, mutations can arise causing changes in the
genes. These mutations are mainly caused by an error in coping the gene. Mutations
can have advantages and disadvantages. An advantage of mutations is genetic
changes that happen randomly. A disadvantage to having mutations within your
body is bacteria can rapidly grow and multiple making the body attack itself.
Selection is when organisms adjust
to their environment and those who survive pass genetic information to their
offspring. This can be referred to as natural selection because organisms that
survive the conditions they are under will survive and be able to reproduce allowing
the transfer of their genes to offspring. The benefit of natural selection is
the development of species branching from their characteristics and environment
types over time. A negative of natural selection is a specie will continue to
die or suffer if they cannot adapt to the changes happening in the environment.
Another part of evolution is sexual selection. Sexual selection is preferring
specific characteristics of the opposite sex and choosing the best. This selection
allows for the greater characteristics to develop among offspring; however, if
the opposite gender cannot mate with the preferred individual their offspring
will not represent the features they want.
Replication, variation, and
selection are all happening in nature all the time, which allows evolution to
occur. Microevolution and macroevolution are affected by the amount of change happening
in the environment. Microevolution is changes within a specie in a shorter time
period. Macroevolution is new species developing from an older specie.
Macroevolution takes a longer because many changes need to occur between the species.
Macroevolution is hard to image because it takes many years for species to develop
and experience a major change within each other.
Species are evolving into many
different species by getting geographically separated which leads to the
different characteristics the specie starts to develop. When species get geographically
separated from each other new species begin to develop due to environmental differences.
These changes start small, but over a period of time the changes are dramatically
different. Once the group of species have changed within a long period of time,
if they were to come together again they would not mate with each other because
they would be considered different species. A specie does not interbreed with
other species. This allows the growth of a variety of species to develop and
A disagreement that is debated is
how DNA is able to show a connection from past years. Another disagreement is
if humans are related to chimpanzees, when did they become hairless. Once a disagreement
happens they are published in a peer-review journal and need further research. The
peer review process allows scientist to compare data and change or test new
hypothesis based on the information they already know.
Evolution is a fact and even though
some scientist may disagree with specific details about it, they overall agree
with the theory of evolution. The evidence found to support the theory of
evolution continues to evolve such as different species are evolving around the
world every day.