How to justify evolving pointy ears that stick out from your head, on a humanoid

Question

How to justify evolving pointy ears that stick out from your head, on a humanoid.

Like this:

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They can either start from the usual round-eared human(oids) with ears close to their heads, or have a different evolutionary path than humans, but in the end, they must end up being basically "humans, but with pointy ears sticking out.", in at least physical and mental ability if not coloration, skin, fur, etc.

Also, the ears... Should work like ears. Yeah.

Also, fully organic, no metal robots that basically just are wearing a skin-suit or anything.

Answer 1

It's required for locating sounds in the vertical plane and increased sensitivity.

Without pinnae humanoids could not localize sounds in the cone of confusion. The pinnae alter incoming sounds subtly in a way that allow us to determine the orientation of sounds. Two ears are required for determining the time difference between arrival times of a sound, which tells us which side of the head sounds are coming from, but without the pinnae, we couldn't tell much more than that.

They also act as a sort of funnel for sounds. Increasing the incoming sound pressure to the ear drum.

The evolutionary advantage comes from being able to tell if that predator sounds just came from above you or in the bushes below you. The different shape might allow increased distinction for localization as well as increased acoustic sensitivity.

Answer 2

Sexual selection. There was a group of humanoids who thought big ears looked good, the humanoids with the biggest ears bred the most, you had a second generation with slightly larger ears, the ones with the pointiest ears bred the most and so on.

Note that you will have to isolate the population somewhat for a significant period of time in order to have a particularly noticeable effect. This is a relatively minor change, but evolution is never fast.

Answer 3

Humans already are able to have ears halfway there.

In most people, protruding or prominent ears are caused by an underdeveloped antihelical fold. When the antihelical fold does not form correctly, it makes the helix (the outer rim of the ear) stick out. (ref)

Ears that look like this work just fine. The only reason to "fix" it is aesthetic (children are often teased). Even the doctors refer to it as "bat ear" or "Dumbo ears" on their websites.

If you want an even less developed antihelical fold, it would be well within the limits of human evolution to achieve. Just select for it. Any reason that gives people with this type of ear more of a reason to reproduce will work. It can be direct (person is more likely to have sex) or indirect (people with protruding ears get all the best jobs and are therefore more likely to find mates...may or may not work in any given culture but...).

Elongating the helix is a more difficult change. But there is a genetic condition called Stahl’s ear (aka Spock's ear) that does this, pointy top and all.

Stahl’s ear is the result of misshapen cartilage. It is characterized by an extra horizontal fold of cartilage (crus). Normally, there are two: superior and inferior. In Stahl’s ear, there is a third horizontal crus. The helix (or upper portion of the ear) may unfurl, giving it a pointed shape. This gives the characteristic “Spock” appearance to the ear. (ref)

Again, there is no different in the ability to hear or anything else. It's all about looks. And looks matter. The ears you want can happen with just two changes to the standard ear. Select for these and you're golden.

But why would these be selected for? Other than considering them sexy (the sort of thing that usually changes in a few generations, if not sooner), what justification could there be for picking one type of ear over another?

And the answer may be, there's not much. Because these types of ears don't cause harm (or benefit) or change hearing, which type moves forward as the standard ear is more about the luck of the genetic draw when a group of humans is small and isolated then grows quickly.

Imagine an extended family (a few hundred people), where both these genetic variations are common, migrating to a new land. Then the people on the old land are mostly wiped out. The species continues to grow from the migrant group, incorporating a few survivors from other groups.

Add some sexual selection into the mix and whoa! elf ears!

Answer 4

If being able to carefully focus a specific frequency band of sound was critical to survival (avoiding predators or other natural enemies, or being better able to seek out a food animal), this would also preferentially select for a given ear shape and size.

Answer 5

Here is a story based on your question:

In the heart of the dense Taryllis Forest, a civilization unlike any other took shape. Here, among towering trees and sprawling undergrowth, evolved the Veridien, a species very much akin to humans but for their distinctively pointed, protruding ears.

The Taryllis was a cacophonous world of noise. With so many species, each with its distinct sounds, survival within the jungle depended on one's ability to distinguish between the subtle nuances in the cacophony. Over time, this selective pressure favored those with larger, more pointed ears that were better at catching and identifying these sounds. This was the first step towards the development of the Veridien's unique ears.

The ears of the Veridien, unlike human ears, could rotate and move independently, similar to some terrestrial animals. This adaptation, combined with their natural shape, allowed them to precisely pinpoint sound sources, a necessary skill for hunting stealthy prey and avoiding the numerous predators lurking in the shadows.

However, survival was not the only factor driving the evolution of the Veridien's ears. In their society, the ears played a crucial role in communication and courtship. Unlike humans who depended heavily on facial expressions, the Veridien had developed a complex language of ear movements. An excited flicker, a slow droop, or an abrupt fold - each movement was rich in meaning.

Over the millennia, sexual selection took hold, favoring Veridien with larger and pointier ears. These were seen as attractive, a symbol of genetic health and strength. The ears became an integral part of their identity, a signifier of beauty, much like the peacock's tail or the lion's mane in other species.

The Taryllis Forest was also a brutally hot environment. The Veridien's protruding ears served as a natural cooling system. An intricate network of small blood vessels running close to the surface of their ears helped dissipate heat effectively, much like the large ears of an elephant.

Evolution is a game of survival and adaptation, and the Veridien played it masterfully. Their pointy, protruding ears were not just an appendage, but a testament to their resilience and adaptation in the face of constant evolutionary pressure. They had become, in essence, "humans" of the Taryllis, their physical and mental abilities honed by their unique environment.

But nature is an ever-evolving stage. What works today might not work tomorrow. As the Veridien looked to the stars and dreamed of exploring new worlds, they wondered how their distinctive ears would fare in environments wildly different from the Taryllis Forest. Only time, and evolution, would tell.