Articles for ielts the dangers of being over-confident

Shapeshift (v)- to be able to change into other people, animals or things. 
Branch out (phr.v)- to start to do an activity that you have not done before, 
especially in your work or business 
Exterior (n)- the way that somebody appears or behaves, especially when this is 
very different from their real feelings or character 
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Inner ears reveal when animals evolved warm blood 
The first warm-blooded animals appeared abruptly 233 million years ago, according 
to clues hidden deep inside their ears.
Before now, scientists estimated that warm-bloodedness, or endothermy, 
gradually evolved over a period of about 120 a million years based on vague clues 
from animals’ skeletons and their environments. But Ricardo Araújo at the 
university of Lisbon in Portugal and his colleagues suspected that the semicircular 
canals in the inner ear might provide a more precise record.
These fluid-filled canals help animals maintain balance and keep their sense of 
orientation. But because temperature affects the way fluids behave, warm-blooded 
animals would, in theory, have had to evolve a different inner ear shape from their 
cold-blooded ancestors in order to keep their orientation system working properly. 
Araújo and his colleagues used an X-ray scanning technique called 
microtomography to examine the inner ears of hundreds of modern animals, 
including mammals, reptiles, birds, amphibians, and fish, and 64 extinct species of 
mammalian predecessors.
They found that in mammals, which are warm-blooded, the inner ear canals 
were more circular and smaller, and thinner relative to their body size, compared 
with those in cold-blooded reptiles, amphibians, and fish.
That trend was so reliable that the researchers soon realized that they could 
identify whether animals were warm-blooded or cold-blooded “with a lot of 
confidence” just by looking at their inner ears, says Araújo.
Armed with that knowledge, the researchers looked at the inner ear canals in 
their ancient specimens spanning several hundreds of millions of years. They 
determined that mammal ancestors first became warm-blooded over a roughly1-
million-year period during the late Triassic, 233million years ago (Nature, 
doi.org/h5vq). This corresponds with the first known appearance of 
mammaliamorphs, ancestors of mammals that may have had the first hairs and 
whiskers.
Source: New Scientist, 30 July 2022

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