Source link : https://bq3anews.com/why-do-not-fish-have-hair/
A dolphin, salmon and sea lion glance virtually not anything alike while you have a look at their pores and skin. Salmon are coated in overlapping scales and slime. The dolphin has clean pores and skin, nearly hairless. The ocean lion, however, keeps probably the most thickest coats within the animal kingdom. All 3 are aquatic vertebrates. The variations aren’t anecdotal: they expose a fundamental rule of evolution that continuously surprises even those that suppose they comprehend it smartly.
The solution lies in masses of tens of millions of years of evolutionary historical past, and presentations how the similar downside – protective and setting apart the frame – will also be solved in radically alternative ways relying at the evolutionary place to begin.
Fish have scales as a result of they by no means wanted hair.
Hair is a feature characteristic of mammals. It advanced most effective as soon as, within the synapsid lineage, the crowd of amniotes that comes with all mammals and their ancestors, which arose greater than 300 million years in the past. However lineage is something, trait is some other: the oldest fossils that point out the presence of hair date again to about 250 million years in the past, from fossilized feces – coprolites – therapsids present in Russia. And the primary transparent impressions of fur correspond to mammals from the Jurassic duration, about 165 million years in the past.
What we do know evidently is that hair was once already…
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Author : bq3anews
Publish date : 2026-05-04 21:18:00
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