this post was submitted on 12 Aug 2023
7 points (88.9% liked)

Ask Biologists 🙋👨‍🔬 🧬

613 readers
1 users here now

Ask anything about all fields of biology. 🧪🧬🔬

We value quality over quantity.


Rules:


You may also like:

founded 1 year ago
MODERATORS
 

Anyone who knows how a skeleton looks like knows that there are spaces between the ribs. However, why does it have gaps between them? Why isn't it a single shell?

you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 12 points 1 year ago (1 children)

The gaps between each rib allow you to curve your chest. If it was a solid shell, you’d be forced to keep your chest perfectly straight, which would impact mobility. Evolutionary pressures preferred mobility over a “shell-like” protection.

[–] [email protected] 1 points 1 year ago* (last edited 1 year ago)

Having a shell like protection wasn’t that necessary in most cases. Turtles needed the protection, but mammals have been doing just fine without it. Probably the flexibility helps too.

Shells are also heavy. If an deer had a shell, it wouldn’t be as fast. Also, the shell wouldn’t really help agains wolves, so that protection would come with a lot of downsides. I guess the only real benefit would be when humans are trying to stab the chest or sides of the deer with spears and arrows.