Post reply

Reply to the message by David Turell

Name:

E-mail: (optional, won't be displayed directly)

Leave this field empty:

Homepage: (optional)

Leave this field empty:

Location: (optional)

Remember me (cookie)

Category:

Subject:

Formatting help

skip to input

format text bold: [b]bold text[/b]
format text italic: [i]italic text[/i]
insert hyperlink: [link=http://example.com/]link text[/link] / [link]http://example.com/[/link]
set text color: [color=#rgb]colored text[/color]
font size: [size=small]small text[/size]; [size=large]large text[/size]
insert list: [list][*]list item[/list]
insert image: [img]http://example.com/image.jpg[/img]; left: [img=left]http://example.com/image.jpg[/img]; right: [img=right]http://example.com/image.jpg[/img]; thumbnail: [img=thumbnail]http://example.com/image.jpg[/img]; thumbnail left: [img=thumbnail-left]http://example.com/image.jpg[/img]; thumbnail right: [img=thumbnail-right]http://example.com/image.jpg[/img]

:-)
;-)
:-P
:-D
:-|
:-(

Message:

> How it spreads seeds:
> 
> https://www.wsj.com/public/resources/documents/5ROSrjoB1ANAAUM9mSdR-WSJNewsPaper-10-21-2023.pdf
> 
> The sesame seeds are neatly lined up inside each compart ment, protected from the world as
> they grow.
> 
> ***
> 
> In the case of sesame, the plant  needs to disperse the fully grown  seeds by opening each capsule in a  way that will let the seeds blow away  on the wind. So the structure of the
>  capsule has a very specific pattern.  Each of its four compartments is  made up of a long C-shaped trough,  with the seeds on the inside. A compartment wall has three layers: The  first two are made of stiff cells full of  cellulose microfibrils, but the outer one is quite different, made from a  much more open and disorganized  collection of soft cells with no stiff  microfibrils.
> 
>  The two inner layers hardly change  when they dry out or get wet, but the  outer layer is like a soft but strong  sponge. When the capsule is growing,  that layer is thick and plump because  it’s full of water, but as the seeds  ripen it starts to dry out. It loses so  much water that it shrinks to 30% of  its original thickness; it also shrinks  asymmetrically. This leaves the whole  outer layer in tension, a bowstring  primed to fire.
> 
> When the tension gets too much— pop!—each compartment pulls away  from the others by breaking at the  line of weakness where the compartments join, snapping back and outward, away from the center. At the  same time, the C-shapes open up, flattening the compartment walls.  Seeds can come flying out at this  point, or they can wait until the wind  picks them up and carries them off.  It’s thought that this sudden reveal is  the origin of the phrase “Open sesame,” made famous in the story of Ali  Baba in “One Thousand and One  Nights.”
> 
> Comment: Viewed as a purposeful design, there is no way a Darwin theory can explain this irreducibly complex mechanism.