Can Mammoths walk among us again?

 

In the New York Times they wrote about a team of Paleo-geneticist and evolutionary biologist were able to sequence the oldest DNA now on record. The previous oldest DNA that was sequenced was 700,000 years old from a horse specimen but one of the 3 mammoths’ fossils that had its DNA extracted and sequenced was 1.2 million years old! the fossils that were retrieved were believed to be that of the Columbian mammoth, this is a species that roamed what is modern day north America. The way that the DNA was extracted from the mammoth was from the molars of each fossils. The molars were described as big as milk cartoons which is a huge tooth. theses molars were drilled into and the material collected were then treated various chemicals and enzymes followed by a washing protocol which isolated the DNA base pairs from each fossil.

              After the DNA base pairs was extracted, they then had to decontaminate it since there are other base pairs from plants, bacteria, and even some humane DNA mixed in with the mammoth’s fossil over time. They then used the DNA of an African Elephant, who is a close descendant of the mammoth, to weed through all the non-mammoth DNA. They were able to use the African elephant’s DNA to match up similar base pairs, they then used it to put the 49 million-3.7 Billion based pairs that were collected from the fossils in the correct order making the DNA fully sequenced. This is now the oldest DNA sequenced, this shows great promise to future studies of the animal and
so many other species since sequencing older DNA is becoming more of a reality.

 This also helped the researchers discover that the once singular evolutionary tree of the Columbian mammoth is no longer singular, the team realized the oldest DNA was different from the 2 other Columbian mammoths DNA sequences. The DNA was similar but different enough to allow the team of researchers to see that the 3 fossils were related but the oldest sequence was different, leading them to believe it belonged to a previously unknown lineage of mammoth. It was previously thought that there was a single lineage of mammoth in Siberia that gave rise to the woolly mammoth and then the Columbian mammoth. However, it turns out that the Columbian mammoth is a hybrid of this new linage and the woolly mammoth. This would have never been discovered without the sequencing of this 1.2-million-year-old DNA. This opens research in a new lineage that they never knew about, allowing them to start to understand how it lived in the past.

This type of research shows that science behind sequencing DNA is not at its limits yet, they now can sequence million-year-old DNA. In the actual Nature article that this paper was published in states that theoretically DNA as old as 2.6 million years can be sequenced since it has been preserved by the permafrost of the ice age which these animals are from. Scientist state that this will not lead to “Jurassic Park”, but it is a possible step in that direction, and I am sure a lot of people expect something like that since we are able to do so much with DNA now such as cloning and gene editing. There could be a real-world possibility that we could see mammoths walking among us again depending on how future research goes with this ancient DNA.   

Sources:

https://www.nytimes.com/2021/02/17/science/DNA-mammoth.html

https://www.nature.com/articles/d41586-021-00436-x

https://www.google.com/url?sa=i&url=http%3A%2F%2Farchive.kuow.org%2Fpost%2Fwhat-do-you-do-when-you-find-mammoth-molar&psig=AOvVaw1JKeHsOXhJbFlv0FtgYx43&ust=1614369244699000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCMDql5vohe8CFQAAAAAdAAAAABAD

https://www.google.com/imgres?imgurl=https%3A%2F%2Fmedia.npr.org%2Fassets%2Fimg%2F2015%2F07%2F02%2Fwoollymammoth-1-4ba6588454a9337c2f2b217b998adb4ce4b4313c.jpg%3Fs%3D1000&imgrefurl=https%3A%2F%2Fwww.mprnews.org%2Fstory%2F2015%2F07%2F03%2Fnpr-checking-dna-against-elephants-hints-at-how-mammoths-got-woolly&tbnid=NYFnOZ4x9m075M&vet=12ahUKEwjtzIfV6IXvAhXECd8KHZZ-A1MQMygHegUIARDhAQ..i&docid=ZvZu1_LtF7nsdM&w=1000&h=748&q=mammoth&ved=2ahUKEwjtzIfV6IXvAhXECd8KHZZ-A1MQMygHegUIARDhAQ      

 

Sea-Stars Suffocating

               While above the water humans are currently enduring a pandemic, under the water, starfish are undergoing an epidemic of their own. Across the pacific coast of North America, starfish are turning into a leathery goo as sea-star wasting disease suffocates and kills many species of starfish. Species such as the sunflower sea stars are being deemed critically endangered as the disease has overcome 90% of their population. The culprit of this epidemic? Climate change and microscopic bacterium.

Photo credit: Kit Harma

               Over time, the Earth’s average conditions have become warmer and warmer. This warming of the Earth has caused the temperatures of the oceans to rise. With this rise in ocean temperature comes an increase in the concentration of organic materials in the waters. Organic materials are defined in chemistry as being carbon-containing with covalent bonding. Certain bacteria called copiotrophs, which are bacteria found in areas with high levels of carbon that rapidly consume carbon for their respiration, begin to thrive continuously as the organic material concentrations keep rising. These bacteria respirate, consuming the organic materials in the water, as well as depleting the oxygen in the water.

               These bacteria also live on the outer surface of the starfish’s skin. When the waters become too warm and the organic matter concentrations reach levels too great, the bacteria reach numbers too high for the starfish to live. The bacteria in large proportions begin to use all of the oxygen up in the water surrounding the starfish to suffocate and die. Starfish don’t breathe like humans; however, they diffuse water over their skin through papulae, which are little skin gills. Without the oxygen to breathe, the starfish “drown,” and this triggers the wasting of the starfish.

               The problems these starfish face are stuck in a cycle of even more wasting and extinction. As more starfish die, more will start to waste. When they die, their organic materials will be consumed by the copiotrophs around them, causing the bacteria to thrive even more. Those bacteria will continue to suffocate the other starfish around them. Climate change is also predicted to get worse and worse, causing the waters to get warmer and warmer on average. Gasses like oxygen are dissolved in the water and the warmer it is, the less energy it will take for the oxygen to escape and leave the water. Conversely, the colder the water is, the tighter it holds onto the oxygen, making it harder for oxygen to escape the water. So with less oxygen in the water and warmer waters containing even more of these suffocating bacteria, the starfish of the world are in a dangerous position.

Photo Credit: MWRD

               There are some solutions that are being investigated to help save the starfish, however. One option that scientists are looking into is to pump oxygen into the water to give the starfish more to breathe with. Another direction that is being researched is the use of ultra-violet radiation to remove the excess organic matter from the waters. The UV radiation can cause organic materials to degrade and break apart. This is done by raising the energy states of the molecules, causing the formation of radicals (free singular electrons), which further break apart more and more bonds. By removing the excess organic matter from the water, the copiotroph populations would drop, helping the starfish populations maintain themselves. With no immediate solution in sight, increasing numbers of species of starfish will near extinction.

               For more information on sea-star wasting disease click here.

Written by Sean Shacklock.

Sources:

https://www.sciencenewsforstudents.org/article/bacteria-suffocating-sea-stars-wasting-disease-goo

https://www.nbcnews.com/science/environment/warming-oceans-may-be-choking-oxygen-starfish-causing-them-drown-n1253355

https://www.sciencedaily.com/releases/2021/01/210106133017.htm