The report is due tomorrow
The report is due tomorrow. the fact that the Arctic and the Antarctic are 12 000 kilometers apart there are some species that manage to both live in and migrate between these two regions
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You’d be forgiven for assuming that the Arctic and the Antarctic are pretty similar ecologically speaking – after all, how different can one frozen wasteland be from another, really? But as much as we might think of both places as similar icy cold environments, there are major differences aside from the obvious one of just how far apart they are from each other. Given the massive distance between the Arctic and the Antarctic, you wouldn’t think there’d be a ton of species that live in both places, but shockingly, there are some species that do just that.
Being members of the same species means that populations need to be able to mate and have gene flow between them, but when it comes to these species, we’re still trying to figure out just how they managed to swap genes with individuals at the opposite ends of the Earth. The Arctic and the Antarctic regions are 12,000 kilometers apart at their closest point. Not only are they far apart, the environments between these poles are extremely different, namely warmer, so it’s hard to imagine a species so globally widespread that it would survive basically everywhere from each frosty pole to the warm waters in between.
Species found at both polar regions are called bipolar in the geographical sense; a species is bipolar if it has populations higher than the latitude of 55 degrees north or lower than 52 degrees south. But that doesn’t necessarily mean all bipolar species are only found at these extremes. Take whales – blue whales, fin whales, and humpback whales are found at both poles, but they hang out in the warmer waters between the poles too, which means we know how they get to either pole – they just swim there.
While these whale migration distances are obviously impressive, the bigger mystery is how teeny little creatures like algae, two worms, crustaceans, and bacteria have ended up in two very distant places – especially when they don’t seem to hang out anywhere in between. The idea of species living at both poles got a lot of buzz when a survey of marine life published in 2009 revealed that at least 235 species were found living in both places.
Now, that doesn’t mean the species referenced in the study were exclusive to the poles – it’s also possible that some of the specimens grouped into one species by this study may actually be multiple species that just, you know, look alike. Since then, genetic analysis has revealed that a number of these allegedly bipolar species should actually be split into separate species across the poles, but other analyses found that some living things like microbes living in both the Arctic and Antarctic are shockingly similar. Gene sequencing revealed that these polar populations were actually more closely related to each other than they were to microbes living much closer to them geographically.
For example, in 2015 researchers studied three bipolar species of ciliates, a kind of single-celled microorganism. The researchers determined that two out of those three ciliates were different enough between polar populations to be considered separate species. However, they also found that one of the ciliate species could still breed with individuals from the other pole, even if they were genetically distinct. An earlier study from 2007 also found that multiple species of deep sea foraminifera, a different type of single-celled organism, were genetically very similar to each other at both of the poles.
There are two possible explanations for this. One is that the foraminifera could just be really common all over the world and live in most of the regions between the poles too, but we just haven’t found them there yet. The other possibility is that even if these species aren’t cross-breeding anymore, they may be evolving so slowly that there’s still basically the same genetic species today.
So, despite the fact that the Arctic and the Antarctic are 12,000 kilometers apart, there are some species that manage to both live in and migrate between these two regions.