WantsToBeUnmade

WantsToBeUnmade t1_jbl2fjj wrote

In the creeping vole (Microtus oregoni) females are XO and males are XX. The offspring always get an X from their father, but their mother gives either an X or nothing.

This only works because their X chromosome carries some of the information that the Y carries in other species.

There is also a clever bit of coding that in most mammals causes less expression of the genes on the X chromosome in females (so that females don't have twice as many proteins running around their body.) And in creeping voles it only does so in males.

Creeping Vole Sex Determination

4

WantsToBeUnmade t1_iz65puk wrote

The Santa Cruz sheep were also regularly rounded up and shorn. They were also culled often. They were feral in as much as no one was actively managing or feeding them, but the fleece was valuable and the locals took advantage of that.

1

WantsToBeUnmade t1_iz1d4mw wrote

>I expect that if left to "go back wild", the first n generations of sheep will probably shed their wool when heat stressed in the summer.

It's a reasonable expectation, but turns out they don't lose their wool to heat stress. It happens regularly in Australia that a sheep escapes or isn't picked up for whatever reason at shearing time, and then survives for years without being shorn. The record is a ram named Chris whose fleece weighed 41kg (90.2 lbs.)

https://www.theguardian.com/australia-news/2021/feb/25/mammoth-woolly-baarack-the-overgrown-sheep-shorn-of-his-35kg-fleece

11

WantsToBeUnmade t1_iu5hzi6 wrote

Like OP said, it's a Quiver Tree. The genus is Aloidendron which literally means "Aloe branched." And that's what they are. They are very closely related to the aloes you can buy in the grocery store, but they grow in a tree form. They have huge inflorescences of yellow flowers that are just like the aloe vera flowers.

As an aside, they are called Quiver Tree because the people native to the area would take a branch, hollow it out, and use it to store their arrows in.

6

WantsToBeUnmade t1_irno3sa wrote

It doesn't really work like that as far as genomes go.

The organism with the largest genome is a plant (Paris japonica.) It has 149 billion base pairs. Humans have 3 billion.

Many plants (estimates range from 30 to 80 percent,) and a fair share of animals are polyploid. That is they have more than 2 pairs of chromosomes. Sometimes many more (some crops have 12 pairs.) That increases the size of the genome without increasing their complexity.

And in animals so many things are learned socially that complexity of form is nearly secondary to learning.

2