So, as temperature increases, when you go from cold-blooded to warm-blooded, the organism will need to modify the structure of the inner ear to compensate for this decrease in viscosity linked to temperature. If you warm up honey, it will be much more fluid. Now, you have to understand that in the inner ear, you have a fluid which is called the endolymph and, as most fluids, its viscosity is affected by temperature. I need to explain that the inner ear is very important for major functions of the body, like stabilisation of gaze, navigation, motor coordination, balance. Now, can you explain how this could be connected to the temperature of an organism. You were actually looking at the shape of the inner ear.
Now, you and your collaborators wanted to look at something which, to many people, might seem completely unrelated to whether a creature is warm- or cold-blooded. And the problem is that there are various ways of assessing metabolism and body temperature of organisms, and often you have conflicting results. You cannot do that on fossil specimens, so you have to choose indirect means to assess these things. It’s hard because in extant organisms you know if one is warm-blooded or cold-blooded by directly measuring its body temperature, its metabolism. I caught up with him and asked why it’s so hard to work out when the first warm-blooded animals arrived. In a study out this week, Romain and colleagues have tried to pin down when this change happened in the mammal lineage, using a surprising line of evidence. This is Romain David of the Natural History Museum in London. You have warm bloodedness in mammals and in birds, and the question was how did this group evolve. But scientists are still grappling with a pretty key question about the history of warm bloodedness. So, this presents a truly fundamental difference between different animals, and warm bloodedness was a major innovation of evolution. For example, species are able to stay more active at night, as well as conquer colder habitats. Being warm-blooded takes a lot of energy, which means having to eat a lot more. To use their proper terms, warm-blooded animals are known as endotherms, and cold-blooded creatures are called ectotherms. Cold-blooded animals get their heat from the environment, whereas warm-blooded regulate their own temperature.
One of the first things we learn about all the different animals when we’re kids is that some of them are warm-blooded and some are cold-blooded. I’m Nick Petrić Howe.įirst up, reporter Adam Levy is investigating a hot topic in the evolution of animals. This week, working out when ‘warm bloodedness’ evolved.Īnd the ultra-efficient enzyme that pulls carbon dioxide out of the air. Head here for the Nature Podcast RSS feed. Never miss an episode: Subscribe to the Nature Podcast on Apple Podcasts, Google Podcasts, Spotify or your favourite podcast app.
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This time, the findings of some big biodiversity reports, and how woodpeckers don’t end up with headaches from their pecking. We discuss some highlights from the Nature Briefing. Now researchers have an idea based on a detailed structural analysis. It also does this extremely efficiently, but nobody has been quite sure how. Hydrogen dependent CO 2 reductase is an enzyme that can convert CO 2 from the air into formic acid that can be used as fuel. Research Highlight: A feeding frenzy of 150 whales marks a species’ comeback 09:47 Structure of an enzyme reveals how its so efficient
Research Highlight: This adhesive bandage sticks strongly - even to hairy skin News and Views: Evolution of thermoregulation as told by ear 07:14 Research HighlightsĪ new surgical glue that’s both strong and easy to remove, and southern fin whales return to Antarctica after being hunted to near extinction. To try to pin down a date, researchers have studied the fossilized remains of ancient mammals’ inner ears, which suggest that this key evolutionary leap appeared around 230 million years ago. The evolution of ‘warm bloodedness’ allowed mammals to live in a more diverse range of habitats, but working out when this occurred has been difficult. In this episode: 00:46 When did mammals start to regulate their temperature?