Introduction
Genetics is defined as the study of genes, genetic variation, and heredity in organisms (1). It's a very vital branch of biology, not only because of how integral it is to biology but also because of how much it contributed to the theory of evolution proposed by Charles Darwin.
(A Short) History
Gregor Mendel, a biologist from the 1800s, is considered the father of genetics. Through his breeding of pea plants, he uncovered that parent organisms can have offspring with various combinations of their traits. This discovery led him to describe genes being passed down before anyone knew what genes were (2). Later, he developed the three principles of inheritance that are well-known throughout the genetic field.
What are Genes?
Made of DNA, genes are a unit of genetic information that determines the physical and biological traits of different organisms. Genes are how different organisms receive different traits from their ancestors. Mendel, the father of heredity, paved the way for genetics when he proposed his laws of inheritance.
When an egg is formed, it is essentially a clone of one of the parents. Before the splitting stage, the egg goes through a duplication phase so that twice the number of chromosomes is in the first egg. Then, the egg goes through a series of separations, where the two chromosomes are split apart, and the original egg splits into two, making it so that there are now two eggs with two of the original four chromosomes. Then, the egg is split again so that there are four eggs with two halves of two of the previous chromosomes.
I'm obviously not a biology teacher and don't have the talent to explain all of the genetics section of biology. So, I will link a really good video on the complete explanation of all the different phases of the egg, including meiosis I and II.
With a great understanding and without a name for genes, Mendel proposed the three laws of inheritance (3):
Law of Dominance: When only the dominant trait is expressed in the offspring, suppressing the recessive trait. (Ex: A purple flower will always produce purple offspring. Two white flowers will always produce white offspring since they have the recessive trait.)
Law of Segregation: Two copies of each trait in a parent are separated during the production of gametes and then are re-united randomly during fertilization
Law of Independent Assortment: Pair traits segregate independently rather than pairs segregate independently rather than as a pair during gamete formation.
This discovery essentially paved the way for genetics in the modern world. Obviously, Mendel did not map out all of genetics, but he gave us a huge start in the field. Now, Genetics, as a field of study, tries to understand which traits are passed down and how they're passed down from generation to generation on a higher level to achieve things that we once thought were unfathomable.
Genetics Now
Genetics in the modern era has a lot of different projects going on because of how wide the field is. Currently, genetics is pursuing these projects (or has completed a majority of it already):
Genetic disease testing: Since we now have a great understanding of different genetic diseases, scientists have come up with a way to test whether or not certain individuals have received a disease only relying on a test. (5)
They are now trying to approve direct-to-consumer tests that allow patients to have access to genetic tests without having to go through healthcare
Gene Therapy: to treat any genetic diseases or conditions, scientists have come up with a way to utilize gene therapy to replace defective genes, introduce healthy genes, or deactivate genes in a patient to prevent those diseases or conditions. (6)
Gene Editing: CRISPR/Cas-9 has come a long way since its creation and now has been combined with the Single Strand Annealing (SSA) pathway. This allows us to utilize CRISPR to modify any genes we want
Epigenetics: This is a combination of anthropology and genetics in a sense, but it basically aims to understand how different environmental factors have affected which traits are passed down in humans.
There are a lot more projects that are being worked on as of right now in genetics and believe me I could talk about all of them for hours, but it's important to understand how all of genetics, its history and its path for the future, has been to understanding humans and the way we function. I believe that going forward, genetics will be a huge player in the scientific field and will continue to do so for the next few decades.
References
Related Posts
