Living things adapt and evolve -- all the time. In fact, the animals we see scurrying around in our backyards are much different than they were many years ago.
But what are some shocking changes we can pinpoint? Examples, and even some mysteries, are hidden in robust collections of preserved creatures from years past to the present, like the library at The Field Museum in Chicago.
"We're the libraries of the material that will allow you to test various hypotheses about how life has changed overtime, or how it might change going forward," Bill Stanley, the museum's mammals collection manager, told The Huffington Post.
From dolphins to deer mice, he pulled back the collection's curtains to reveal how modern-day species are changing over time. Watch the video above and/or click the link below for a full transcript. Plus, leave your thoughts in the comments section. Come on, talk nerdy to me!
JACQUELINE HOWARD: Hey everyone, Jacqueline Howard here. We live in an evolving world. People, places, and things are constantly changing. That's evident at The Field Museum in Chicago, where more than 24 million specimens and objects are housed for research -- googly-eyed bats in jars, freaky frozen furry creatures, scary skeletons ravaged by flesh-eating beetles. Yeah, it’s ghoulish, but it’s also science. Each specimen can show us examples of evolution -- and is studied by scientists to pinpoint specific changes in a species’ morphology, that is its shape and form. These changes aren’t just seen in the past, but the present, and may shed light on the future. But how? And why? Well, I’m here at The Field Museum to find out. I’m going to meet with mammals collection manager Bill Stanley, and this could get wild.
BILL STANLEY: People often ask well, what are some very extreme changes that we can see in mammals that we’re familiar with? And my favorite is the dolphin. Cetaceans reinvaded the sea after being upon land as land mammals for long periods of time and as they got further, and further out to sea, they lost the need for their back legs and we can see this in the fossil record. When you lose the back legs, you lose the need for the pelvis. These bones here are free floating in the back-third of the animal and are the remnants of the pelvis.
JH: That’s an extreme example of gradual change. And if you take a close look at deer mice -- they’ll show you change in action. Recent studies have suggested changes in the little rodent’s skull size, and even one population’s coat color. But Bill said there’s also something called punctuated equilibrium. That's when evolutionary change seems to have taken place in a very short period of time -- there may be no intermediate forms of the species, so that sometimes eerily leaves no timeline. Case in point? The hero shrew.
BS: There is one shrew that is from the standpoint of the vertebral column, the most bizarre mammal in the world. With this animal, given that there are no transition forms -- there is nothing in between this vertebral column morphology and the morphology of all other shrews or all other mammals -- this has been suggested to be an example of punctuated equilibrium, where everything was constantly the same shape roughly speaking until a very marked change in the morphology of the vertebral column in a very short time frame.
JH: The vertebral column is similar in all mammals. See that? It’s the lumbar region of a typical cat, and most mammalian spines look like that. Mine, yours, even your dog’s. But here’s a change in the spine of a shrew that, as Bill called it, is bizarre.
BS: This is the hero shrew, and unlike you or I or the cat, there are 15 to 20 processes on the sides of these vertebrae and they interlock. And the muscles that are associated with this, and this fortified lower region of the backbone, give this animal incredible strength. Now here’s the mindblowing part, we don’t know why.
JH: Behind these doors is the wild, and sometimes downright creepy way scientists learn more about change in species to answer that question: Why? Scientists stash and study dead animals, once they've died, spanning over centuries, to pinpoint changes in morphology. The animals are frozen and dissected before researchers then preserve their skins, skeletons, and...
BS: The other way that we often preserve animals is to pickle them. By that I mean the animal is injected with formalin and then switch to ethanol, so this is a hammerhead bat that is sitting in a jar of 70 percent ethanol.
JH: Eek! But, let’s keep it one hundred. What’s the point of all this?
BS: These animals are very much a part of the fabric of our lives. They may be eating seeds that are important for plants that we like. They may be pollinating trees that are vital for getting medicines from. They may be food for raptors that we like to watch. They may be carrying ticks that carry certain diseases. If we can predict how these animals are going to change, then we can predict what’s going to happen with all these other things that these animals are so integral to.
JH: I told you things could get wild. But seriously, how cool is it that animals we see everyday are constantly changing? Let me know what you think. You know the drill, talk nerdy to me!
See all Talk Nerdy to Me posts.