FEB 25, 2016 3:15 PM PST

What Darwin Didn't Foresee

WRITTEN BY: Kara Marker
In the middle of the 19th century, Charles Darwin published On the Origin of Species, which contains his theory of evolution. According to Darwin, only the genes that benefit an organism’s fitness get passed down over time to the next generations. However, scientists have found a gene in mouse populations that defies Darwin’s theory, thought to be tried and true after hundreds of years since the publication of On the Origin of Species.

What’s the “selfish” gene in the spotlight? It is called R2d2, and it “cheats” during female meiosis to ensure that its alleles get passed down to the offspring being created. The process is called meiotic drive, and it goes against the life work of another demigod of genetics: Gregor Mendel.
 


Also known as the Father of Genetics, Mendel is famous for his 1865 genetic principle, the Law of Segregation, which states that there is an equal chance of a maternal or paternal allele of being transmitted to offspring.

With meiotic drive, R2d2 alleles spread quickly through both laboratory and wild mouse populations. In their study published in the journal Molecular Biology and Evolution, scientists from the University of North Carolina at Chapel Hill School of Medicine showed for the first time how a selfish gene can become fixed in a population of organisms.

Why is R2d2 so selfish? Not only do its alleles push their way through meiosis, they actually reduce the fertility of females, causing them to have fewer offspring. This reaction is completely counterintuitive to the survival of the species, yet R2d2 alleles soar through mouse populations.

“This trade-off is what makes R2d2 selfish,” said graduate student and co-author Andrew Morgan. “If meiotic drive is strong enough, then it increases the frequency of alleles that decrease reproductive fitness."

According to Pardo-Manuel de Villena, PhD, senior author of the paper, unlike other genes that rise to the top because they help an organism adapt to new surroundings by surviving and reproducing, the rise of R2d2 has “nothing to do with adaption.”
 

Source: UNC Healthcare System
About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
DEC 29, 2019
Cell & Molecular Biology
DEC 29, 2019
A Molecular Switch for Modulating Gene Therapy Doses
  Genetic errors cause many different kinds of diseases, and gene therapy has aimed to relieve those symptoms by addressing the root cause....
JAN 20, 2020
Genetics & Genomics
JAN 20, 2020
Epigenetic Changes Make Breast Cancer Cells Drug Resistant
Researchers have found that changes in the structure of the genome in breast cancer cells can make them resistant to drug therapies....
FEB 02, 2020
Cancer
FEB 02, 2020
These cosmetics damage breast cells' DNA
A new approach to studying the effects of two common chemicals used in cosmetics and sunscreens found they can cause DNA damage in breast cells at surprisi...
FEB 09, 2020
Cell & Molecular Biology
FEB 09, 2020
Learning More About X Chromosome Inactivation
The X chromosome carries a thousand genes, so in females, one of the X chromosomes must be silenced to avoid serious developmental consequences....
FEB 23, 2020
Genetics & Genomics
FEB 23, 2020
Revealing More About the Genetic Mechanisms Underlying Down Syndrome
Down syndrome impacts around 6,000 live births in the US every year. Around 95% of affected individuals have a type called trisomy 21....
FEB 26, 2020
Neuroscience
FEB 26, 2020
Immunotherapy Could Be Used to Treat Traumatic Brain Injury
Video:  Further explaination of microglia and their various functions.  Traumatic Brain Injuries are physical injuries to the brain which cause i...
Loading Comments...