Explaining Evolution
Genetics and Heredity
In anthropology, you must study the theory of evolution.
Anthropologists study how humans changed (evolved) over the years. The
theory of evolution took a big step forward with Darwin's discovery of the
process of natural selection. (Remember, natural selection is a natural
process that results in the survival and reproductive success of individuals
or groups best adjusted to their environment and that leads to the
perpetuation of genetic qualities best suited to that particular environment.
Keep thinking about natural selection - we'll be seeing it again soon.)
Eight years after Darwin published
On the Origin of Species
, an
Austrian monk named Gregor Mendel published the results from his studies
of crossbreeding pea plants. In his research, Mendel discovered the
principles of
heredity.
Heredity is the process by which genetic traits are
passed from parents to their offspring. However, his work was not accepted
by the scientific community for over thirty years.
Have you ever seen a liger?
How about a goldendoodle?
You may be asking yourself two questions: How? And what are they?
Well, they are hybrid animals created by man for different reasons. In
the case of the goldendoodle, it was bred to be a service pet for people
with allergies to fur. Golden retrievers shed, but poodles do not. In the case
of the liger, its breeding is believed to have been accidental.
Whatever the reason, there are numerous examples of hybrids in the
animal and plant world. (Have you ever had a tangelo?) Now, these
examples are not about evolutionary changes but rather instances of
human-driven artificial breeding.
What does any of this have to do with anthropology? Well, the study
of genetics and heredity is an important aspect of evolution. Evolution has
a big impact on anthropology.
Mendel's Research
When Mendel was studying pea plants, he identified seven different
genetic traits. He followed these traits throughout the course of his
experiments. The first of the genetic principles that Mendel discovered was
the principle of segregation. This principle states that a parent's genes
separate, and only one half of the genes will then be passed on to the
offspring.
Genetic traits are passed from generation to generation. Are you tall?
Do you have blue eyes? Is your hair curly? Your physical characteristics
come from your parents and grandparents. A lot of progress in genetics is
credited to Mendel. Mendel determined that certain traits are dominant,
whereas others are recessive. Dominant traits are those traits which are
always expressed in an organism. Recessive traits only occur when the
dominant traits are not present.
