Science is a fickle mistress, and just when scientists think they understand something completely, they discover an entirely new facet of the subject that totally reverses that position. Biology is one of the areas of science most affected by this phenomenon, and scientists are constantly adding to the wealth of knowledge that humanity has already built on the subject. Genetics is perhaps the most significant driving force behind biology since life would not exist as it does today without DNA, and the complexity of DNA is such that humanity may never fully understand the nuances of those tiny molecules. Below are just a few examples of amazing genetic discoveries made in the recent past.
52 Million-Year-Old Tomatillo Fossils
There are over 2,400 species of plants that make up the genetic family known as the nightshades, and many of those species contribute to the food supply, including peppers, potatoes, and tomatoes. Tomatillos are another member of the family, and while the entire nightshade family was thought to be about 30 million years old, it was once thought that tomatillos evolved roughly 10 million years ago. However, a new set of fossils were recently unearthed that forced scientists to rethink their entire idea about nightshades. These tomatillo fossils were calculated to be 52 million years old, which means the entire nightshade family must be at least 22 million years older than previously thought.
Genetic Cause of Schizophrenia
Schizophrenia is surprisingly common amongst the civilized world, and roughly one percent of the entire American population suffers from some form of the condition. For years, researchers have assumed there is a genetic component to the disease, but it wasn’t until quite recently that link was discovered. According to the latest findings, schizophrenia is caused by a genetic stamp in a young child’s mind that causes excessive ‘pruning’ of extraneous synapses formed during early childhood and infancy. This pruning is completely normal in health individuals, but schizophrenics experience too much pruning, which impairs mental function. The recent findings that outline the genetic stamp could eventually lead to effective treatment for schizophrenics before they show any signs or symptoms of the condition, according to Transnetyx, Inc.
Unknown Human DNA in Aboriginal Australians
Scientists have recently discovered that natives to north-east Australia and Papua New Guinea carry tiny fragments of DNA that once belonged to an extinct human predecessor species that has yet to be identified or catalogued. For the longest time, scientists assumed people from those locations were the descendants of Neanderthals and Denisovans, but recent evidence shows that a third group must have also contributed to the development of aboriginal Australians. This is particularly exciting because it is the first time a new species of ancient human has been discovered through nothing but genetic evidence in the living ancestors of that species. The discovery could point to the idea that human history is far less complete than what is currently known.
CRISPR was first discovered several years ago, and it is basically a natural gene-editing tool that uses an existing genetic processing system to protect against problems with the genetic code. In natural systems, CRISPR identifies genetic material that is harmful and ‘knocks out’ the functional part of the DNA. For the first time, that natural tool has been tweaked to treat an existing illness. A group of Chinese researchers were able to use CRISPR techniques to treat a man suffering from lung cancer. They used the CRISPR technology to remove genes from the man’s natural cells that allowed the cancer to spread faster, however the results have not yet been revealed. Should the results be successful, it could usher in an entirely new era of genetic medicine.
Asexual Reproduction in Zebra Sharks
A zebra shark at the Reef HQ Aquarium in Australia surprised her handlers recently when she laid three eggs that eventually hatched into baby sharks. The surprise came from the fact that the shark, named Leonie, was in a tank with no male zebra sharks. Genetic testing proved the babies were the result of a single parent, meaning they were literal clones of their mother. This is a biological function called parthenogenesis, which described female reproduction without eggs being fertilized by a male. The function is surprisingly common in nature, especially among invertebrates, plants, and other lower forms of life. However, this was the first time such behavior was recorded in a zebra shark.