Hello. Welcome to the Planetary News Radio Episode Number 10 with your host, Bryan White. I’m going to be doing a Science in the News segment today, which is a brief summary of trending science news articles. I haven’t reed or researched most of these articles unless it was something controversial. So I’m just giving background information based on the headline. So depending how good the headlines are kind of influences how much information I can give about the article.
First up, I have here “DNA from 31,000 year old milk teeth leads to the discovery of a new group of ancient Siberians”. Ancient humans. This is a really exciting area of research because we found out that pretty much anything say, around the last 50,000 years, we can get DNA from now if we can find bones and the bones haven’t been completely fossilized. There’s still organic material in the bones. We can extract DNA and do genetic and genomic analysis on these bones and teeth are a great example of that. [There is] lots of organic material inside of teeth. And so we’ve discovered there’s several species of ancient humans in Eastern Europe, across through Russia, and Siberia, and in Asia. And so while there were radiations of humans out of Africa multiple times, some of those radiations included ancient humans that migrated into Siberia and Asia. In Europe, some of those became Neanderthals. [In Russia and Asia,] some of those became Denisovans, and I don’t know if this new species has been named yet [(Ancient North Siberians)]. This is really considered a subspecies of [ancient human, which are still considered Homo sapiens sp.].
Most of these species would have been able to interbreed with each other. So a good rule of thumb for mammals is if the divergence time for two groups is less than 200,000 years, then hybridization was most likely possible. So modern humans and Neanderthals were [able to hybridize, which] we know it’s proven for a fact that they hybridized because we have genomic data. Using [just] the rule of thumb, we know that Neanderthals and modern humans diverged about 300,000 years ago, and when they met again in Europe, they were only separated by about 200,000 years of evolution, and so they were able to hybridize. So the same thing with this [newly discovered group whose] teeth are only 31,000 years, so certainly these would have been able to hybridize and interbreed with modern humans, Homo sapiens sapiens.
So [this is] just more evidence of new, different groups of ancient humans. And why is that important? Well, it helps paint the picture of the migration and really the prolific amount of adaptation that modern humans underwent in terms of evolutionary change over the last 200,000 years. We really had our own adaptive radiation, just like birds and reptiles and dinosaurs. Humans are one of our own great adaptive radiation stories in terms of evolutionary history, so it’s always cool when we find new human species or unique genetic groups.
So let’s see, we [have] another StarLink article. “Astronomers call for urgent action on you on SpaceX’s StarLink satellites”. Apparently, astronomers are still concerned over the magnitude of the number of satellites that Elon Musk is going to be putting out into orbit around. [It will be] 12,000 satellites [in total], and this is now still a trending story every week for the last couple weeks since the initial launch has occurred. Like I said last time, I think it’s a fair criticism, but it also forces us to think about space junk in general, which is good. So Maybe Elon Musk is doing us a favor by forcing the conversation, and hopefully there’s some resolution with these satellites and [policies towards “space junk”].
Here’s another interesting evolution biology topic or medical two. The newest lab rat has eight arms octopuses, big brains and unique behaviour spur basic research. Why would octopuses be a really good animal to use in the lab as a research subject? Well, let’s think about rats. Rats are intelligent. They’re small. They’re relatively easy to cultivate. You could have a colony [colony of rats]. They reproduce in the lab. They have a short lifespan, and that life span is about the time that it takes most experiments to perform. But what are the problems with rats? There’s a lot of problems with rats. One of them is that rats get cancer very easily, [upwards of 80% in some cases]. At least in lab stocks of rats, as opposed to wild rats. We’ve been cultivating rats for so long in the lab in a lab setting that they’re very, very likely to get cancer over the course of a two year life span. And so, if you want to do a cancer study on rats, that’s a problem because most of these rats will inevitably get cancer no matter what, whether they’re being exposed to something that is actually increasing their cancer risk or if they’re just living over the course of a normal life span.
[What are some reasons octopuses might make good lab animals?] Octopuses are less cultivated in the lab, [or at least were used in lab experiments more recently], so we probably don’t have very many generations worth of octopus evolution happening in a lab. It would be easier to collect them from the wild and generate a new stock [to improve and maintain lab-strain genetics]. Since lab rats are so domesticated compared to their wild counterparts, it would be problematic to intermix lab rats with wild rats, especially because you have the problem of aggression. So you don’t want to create really aggressive lab rats. It might improve their genetic stock, but then again, you have a problem of having more wild, aggressive rats.
Octopus can be aggressive, but it’s different. They’re a very different animal in terms of behavior. They’re contained in a marine environment. They’re probably not really being handled by the researchers. In other words, an octopus is less likely to reach around and bite a researcher because the environment that the octopus is being stored in isn’t going to be one where the researchers are routinely handling them with their hands. I imagine you can create these lab complexes for octopus to live in, where the researchers don’t really have to interact with them, and they don’t have to worry about getting bit. Octopuses do have a beak that could hurt a human. It could draw blood. But again, they’re not really aggressive, they’re mostly defensive animals, so octopus is not really threatened. Even a wild octopus shouldn’t be a problem. Now they will try to escape, but that’s part of their intelligence. So you have this animal that has a really fast generation time, it has a genetic stock could be easily replenished from the wild, it’s highly intelligent, it’s probably smarter than rats. It’s not really aggressive [compared to rats]. On the negative side, it’s probably more expensive to cultivate because you need all the marine equipment. But stuff like that is coming down in terms of pricing because of advances in material science. So as material science advances, it becomes easier to cultivate an animal like an octopus and then for sets of experiments that will work on an octopus. In other words, if you’re not trying to test a [mammal-specific] hormone, obviously that won’t work. Or it might if you could genetically engineer octopus to do something like a mammal. So maybe we can even test human medicine on octopuses if it’s easy to genetically modify them.
The great dying nearly erased life on Earth. Scientists see similarities today, the great dying, of course, being the Permian extinction, where 90 percent of marine life went extinct at the end of the Permian period around 300,000,000 years ago. And I think maybe 70% of all land life went extinct. And so we see Similar is of that today because of the rapid extinction rates that were seen on the Earth. And so we know that the Permian extinction was accompanied by rapid changes in climate, and a lot of those changes would have been recorded in the geological history in the fossils in the rocks around that time. So we’re probably seen similar patterns of a very rapid global climate change too rapid for animals to adapt, especially marine animals that tend to be more sensitive.
Apparently, the Mars lander Insight is having a problem with its instruments. So “NASA finally has a plan to free Insight’s extremely stuck probe”. So it sounds like the heat probe on Insight os stuck. Insight is an interesting probe on Mars because it’s not a robotic rover like Opportunity [and Spirit were]. It is a It is a stationary probe whose primary mission is to study the geology and geologic activity of Mars. So it has a seismometer that is actually measuring earthquakes on Mars and some other types of thermal instruments. So the fact that one of its probes are stuck is not good, but maybe this can be resolved.
Here’s another controversial topic. “Microplastics have invaded the deep ocean and the food chain”. That’s not good. So micro plastics real problem, because we’re finding out now that it’s permeated our entire water system, including the ocean and freshwater. These are microscopic bits of plastic that now we know we’re drinking and eating, and not just us [(humans)]. All life on earth now potentially being exposed to this. We don’t know the cumulative effects or long term effects of this because it’s just recently happened [the article says we are] finding out that microplastics have permeated all the way down to the deep sea, which means the entire oceanic ecosystem can be impacted from this all the way from the bottom up. So [some of] the primary producers in the ocean are phytoplankton or very tiny, tiny animals [(zooplankton)]. Phytoplankton are photosynthesizing organisms that float up and down in the water. And so now it sounds like, they’re saying, is that microplastics have permeated the entire oceanic column, which means primary producers will be affected as well as secondary producers and secondary consumers.
So if the oceanic ecosystem has been permeated to this degree with microplastic suggests that there could be a cumulative effect and this could lead to an ecosystem collapse. And so I think that’s kind of what we’re waiting for right now. In terms of conservation biology, we’re waiting to start seeing signs of these major ecosystem crashes. We already see signs of top level consumers [being harmed, such as] whales, sea turtles, things like that that are eating fish all the way up the food chain. We already see that they’re being impacted because they’re getting the worst degree of bio-accumulation because they’re eating fish and crustaceans that even in phytoplankton have been absorbing microplastics. So, you know, at the highest level we already get an impact. We get birds stomachs filled with plastic, things like that. So this microplastic problem is really scary. And hopefully my guess is that there will be some extreme measures taken, probably in the next five years to alleviate this. That’s my hope. But I think that it will happen because I think we’ll start seeing more direct [negative] impacts of it that will drive some of those changes.
All right, and that’s all I had today for this Science in the News segment. That’s Bryan White signing out the Planetary News Radio. Thanks for listening. If you’d like to support this podcast that had a patreon going, the link for that is in the feed. The transcripts for all of these podcasts are also on the website, so there’s a link to the website in the feed, and if you would like to join a discord chat, that link is also there. Hopefully, we get people asking questions and things like that in the discord, so thanks for listening. Have a great day.
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