Today, if you’ll indulge me, I’m gonna chat a little bit about Ungulates, and as such summarise the article “A climatic explanation for patterns of evolutionary diversity in ungulate mammals“. As I’m sure you clever chaps all know Ungulates come in two types, odd-toed and even-toed. Odds are horses (donks and zebras included), tapirs and Rhinos. Your evens are much more varied, sheep, cows, goats, giraffes, pigs, deer, hippos..the list goes on. So why did the Even-toed ungulates diversify so much when the odd-toed stayed pretty much in the horsey region (Honestly- Rhinos are super horsey, look it up.) ?
It has often been attributed to their different gastrointestinal tract: i.e. Even-toed ungulates are ruminants with a forestomach fermentation site, rather than the hindgut (the cecum) as the site of fermentation, and that this mode of digestion is superior.
So, the Odd-toed reached their diversification peak in the late Eocene with 13 families, 9 of which were extinct by the Miocene. Now, despite the assumption than the even-toed where better suited to their environment due to their gastrointestinal oddities, all the even-toed who went extinct in the were omnivores or obligate folivores and those that survived were, you guessed it- hindgut fermentors just like the odd-toed.
The paper shows that the reduction in hindgut fermented ungulates correlates with climactic changes rather than out competing. So in the middle Eocene, even-toed ungulates were small, and living in low-seasonality regime forests, and as the climate changed, and herbage became sparse, the even-toed got larger to better withstand the seasonal changes in food availability. Meanwhile the larger odd-toed ungulates went extinct. Maybe forestomach fermentation isn’t so superior after all! Suck it cows.
I’m the ZooLOLogist, and I read crazy long journal articles so you don’t have to.
Fish are getting stoned
We’ve all heard of the hormones in contraceptive pills finding their way into waterways and affecting fish, making manfish grow boobs and all that, so it follows that other drugs would affect fish too.
A recent swedish study has looked into how our overmedicated population might be affecting fish, specifically Oxazepam which is a Benzo usually prescribed for anxiety disorders. This is a drug which is found in rivers and streams in small amounts, as it is excreted by humans taking it, and the sewage…you don’t need me to explain how sewage works.
As is oft the case with behavioural studies, it’s easier to do it in the lab, so fish were dosed with the same levels as found in the rivers. In humans Oxazepam can cause risk-taking behaviour and hostility..in the fish? Well they called it “bolder and less social”…which sounds a bit like risk-taking and hostility doesn’t it?!
It’s not surprizing I suppose that drugs which affect the nervous system would affect all chorates similarly, but it’s a worrying thought that our reliance on drugs is affecting our fauna in this way.
Ok, what would be the funniest animal/drug combination? I’m going for frogs with tramadol-induced drowsiness
Nah, you guys go without me..Im just gonna *yawwwwwwwn* stay…here…
Leave a comment
Filed under Comment, Journal
Tagged as drugs, environment, fish, humans, pollution, research