Why are Lemurs Terrified of Predators that don't Exist?

in the 19th century the United States Army acquired 30 dromedary camels from the Middle East to test if they would be better suited for traveling around the southwest of the country than horses the United States Camel Corps experiment was eventually dropped as it interfered with the American Civil War however it was noted that the camels loved eating the leaves of the creosote bushes that grow in Mexico across the border States while these bushes have a rich ecological relationship with insects they are not commonly eaten by mammals Jackrabbits are the only mammals that eat the leaves and only really eat them if there is no other food available despite this these large mammals from another continent we're eating them as they evolved to eat food like this so why is this avocados have a very large stone that can't really be eaten in dispersed by any animal in the Americas as little as 12,000 years ago there were plenty of very large animals all over the Americas that could swallow avocados whole there were GAMP athere's that were peculiar-looking prevacid ian's distantly related to elephants giant sloths like megalonyx and of course large mammoths the avocado would have co-evolved with these large creatures and so having large stones was no problem for large guts unfortunately at the end of the last glacial period most of the megafauna died out and the avocado should have got with them although humans arrival on the continent is suspiciously close to the extinction of the megafauna luckily they also started cultivating avocados and saved them from extinction avocados look very out of place now with all the other small seeded fruit but their existence is easily explained by coevolution of since extinct creatures the reason for the dromedary camels finding the creosote bush so irresistible is for the same reason if not in Reverse despite the subconscious association with camels in the Middle East camels actually evolved in North America and have since gone extinct adding to this the camel lived across the Bering Land Bridge into Siberia was called Hera camelus which is not that distantly related to modern camels the camels may have been able to eat the leaves of the creosote bush with little issue because they evolved to eat them or maybe bushes similar to them when an animal evolved for an ecosystem that no longer exists it is called an evolutionary anachronism and there are countless examples of this also found in North America the pronghorn is a second fastest animal in the world and the fastest when concerned with sustained speed the unusual thing is that this doesn't seem to make any evolutionary sense they have extremely powerful almost over evolved muscles that are very specialized for high-speed but no predators in their range they're anywhere near as far the only animal that can reliably prey on huddled pronghorns and mountain lions and even they can only do this if the terrain allows for an ambush some of the predators from America's fairly recent past were much better suited for speed and would have lived alongside the pronghorns there were more species of feline and as Jaguars used to reside in North America as well and also there was a massive American Lions it is possible that the short-faced bear may have been a regular predator of the pronghorn as modern-day black bears are also known to chase them but with little success short-faced bears on the other hand have been known for some time to have better specializations for high speed and extent bears and they would not need to run much faster to be realistic predators of the pronghorns however the most likely candidate for the pronghorn selective pressures other species of American cheetah that used to be found in North America they were similar to modern-day cheetahs but not closely related and if they could reach anywhere near cheetah speed this would explain why the pronghorn can run so fast cheetahs can also only run over top speed for a matter of seconds so this would also explain why the pronghorn is a good at sustained speed evolutionary anachronisms are similar to vestigial organs but are not to be confused as they are different but if categorize organs that evolved to deal with pressures that no longer exist in the present day however a bowhead whale is unable to use the tiny bones remaining from where its hind legs would be making them vestigial whereas although a pronghorn running specializations are no longer needed they are still able to use them so in the case of anachronisms the organs that have evolved very no longer needed purpose are still usable these phenomena can also create behaviors in animals that may have once aided in survival but are no longer necessary certain species of lemur such as the ringtail lemur are very rarely hunted by predator but as they are too big to be reliable prey for any of the birds in Madagascar although certain hawks on the island actually present little threat to these creatures particularly the large ones they react strongly to their presence with vigorous alarm calls as noted by many scientists their fear of birds of prey seems to be very over-the-top for the threat level it is known that a much larger bird of prey called a Malagasy crowned eagle once lived in madagascar and died out as little as five hundred years ago this bird is thought to have been around the size of a Golden Eagle and as much as twice the size of any currently living bird of prey in Madagascar as such it probably presented a real threat to even large species of lemur the fear of predatory birds could have developed in the past even though this large bird has gone extinct evolutionary anachronisms affecting behaviour is actually something that you experience every day as it is very prevalent in humans something called supernormal stimuli is in fact very similar to evolutionary anachronisms in psychology a super normal stimulus is when an evolutionary urge receives a stimulus that has a much stronger response for which it has evolved for example humans have evolved certain cravings for fat salt and sugar that can now be satisfied to a much greater extent with modern junk food and typical food that's found in nature it has also been argued that television satisfies certain social cues like laughter and smiling face it's much more frequently than you could receive in real life some psychologists argue that supernormal stimuli govern the behavior of humans just as much as in non-human animals unfortunately evolutionary anachronisms can also be seen as our last living links to the megafauna they used to inhabit the northern hemisphere as little as ten to thirteen thousand years ago as a result these animals that are evolved to a different time are often endangered like the largest bird in North America the Californian condor these birds are critically endangered and were once almost extinct scavengers are often very successful creatures but without mammoths and giant sloths they are far too big for the environment they live in and as such their numbers have dwindled luckily Californian condors were able to stave off extinction because they specialized eating washed up sea creatures adding to this the conservation efforts in recent decades of them have a small increase in numbers however this shows that evolutionary anachronism offers some of the best arguments for bringing back certain extinct ice age beasts thank you for watching if you'd like to be notified of future uploads for me then consider subscribing [Music]

Channel: Moth Light Media

Views: 334,355

Rating: 4.9468741 out of 5

Keywords: evolutionary anachronism, evolution, camels, lemurs, lemur evolution, paleontology, supernormal stimuli, humans in a crisis, giant cats, prehistoric felines, american lion, panthera atrox, american ch

Id: CXvR5v6MyQg

Length: 7min 0sec (420 seconds)

Published: Sat Mar 30 2019

Reddit Comments

[u/FreudJesusGod]

Most evolution happens over 1000's, 10 000's or even 100 000's of years. If the eagle that ate lemurs died off as little as 500 years ago, there hasn't been enough time for the lemurs to evolve away from that behaviour.

Try again in 5000 years and they probably will have stopped caring about aerial predators.

[u/blueooze]

got a subscription out of me

[u/Daldain]

Very educational, thank you author.

[u/SkyllianVerge]

Subbed. This was awesome.

[u/lambmoreto]

Should we be trying to prevent unadapted species going extinct? I kinda get it when we're the cause, even if it's a bit egotistical of us, but if a species is going extinct because it is not fit for the environment surely we shouldn't be fucking with the natural process

[u/tangoshukudai]

I am not convinced that them being scared of a bird that can't eat them is because of some evolutionary anachronism. I think it is because birds are just god damn scary.

[u/Wonderful_Delivery]

We should bring them all back.