Accessible MooTools Widgets

Accordion

The Accordion gives you a fancy way to only show the really needed content.

History

Common ancestor

The first suggestion that all organisms may have had a common ancestor and diverged through random variation and natural selection was made in 1745 by the French mathematician and scientist Pierre-Louis Moreau de Maupertuis (1698-1759) in his work Venus physique. Specifically:

"Could one not say that, in the fortuitous combinations of the productions of nature, as there must be some characterized by a certain relation of fitness which are able to subsist, it is not to be wondered at that this fitness is present in all the species that are currently in existence? Chance, one would say, produced an innumerable multitude of individuals; a small number found themselves constructed in such a manner that the parts of the animal were able to satisfy its needs; in another infinitely greater number, there was neither fitness nor order: all of these latter have perished. Animals lacking a mouth could not live; others lacking reproductive organs could not perpetuate themselves... The species we see today are but the smallest part of what blind destiny has produced..."

The first suggestion The second suggestion

Evidence of universal common descent

Common biochemistry and genetic code

All known forms of life are based on the same fundamental biochemical organization: genetic information encoded in DNA, transcribed into RNA, through the effect of protein- and RNA-enzymes, then translated into proteins by (highly similar) ribosomes, with ATP, NADH and others as energy currencies, etc. Furthermore, the genetic code (the "translation table" according to which DNA information is translated into proteins) is nearly identical for all known lifeforms, from bacteria to humans, with minor local differences. The universality of this code is generally regarded by biologists as definitive evidence in favor of the theory of universal common descent. Analysis of the small differences in the genetic code has also provided support for universal common descent.

Examples of common descent

Artificial selection

Artificial selection offers remarkable examples of the amount of diversity that can exist between individuals sharing a late common ancestor. To perform artificial selection, one begins with a particular species (following examples include wolves and wild cabbage) and then, at every generation, only allow certain individuals to reproduce, based on the degree to which they exhibit certain desirable characteristics. In time, it is expected that these characteristics become increasingly well-developed in successive generations. Many examples of artificial selection, like the ones below, occurred without the guidance of modern scientific insight.

How to use the Accordion widget

An accordion component is a collection of expandable panels.

Tab: When focus is on an accordion header, pressing the Tab key moves focus in the following manner:
1. If interactive glyphs or menus are present in the accordion header, focus moves to each in order.
2. When the corresponding panel is expanded, then focus moves to the first focusable element in the panel.
3. If the panel is collapsed, OR, when the last interactive element of a panel is reached, the next Tab key press moves focus as follows:
  - If a subsequent accordion panel is already expanded, focus moves to the first focusable element in this subsequent panel.
  - If no subsequent accordion panel is expanded, focus moves to the first focusable element outside the accordion component.
Shift+Tab: Generally the reverse of Tab.
Left Arrow / Up Arrow: When focus is on the accordion header, a press of up/left arrow keys moves focus to the previous logical accordion header. When focus reaches the first header, further up/left arrow key presses wrap to the last header.
Right Arrow / Down Arrow: When focus is on the accordion header, a press of down/right moves focus to the next logical accordion header. When focus reaches the last header, further down/right arrow key presses wrap to the first header
Ctrl+Up Arrow: Moves focus from anywhere in the accordion content to its associated accordion header or tab respectively.
End: When focus is on the accordion header, an End key press moves focus to the last accordion header.
Home: When focus is on the accordion header, a Home key press moves focus to the first accordion header.
Enter/Space: When focus is on an accordion header, pressing Enter/Space toggles the expansion of the corresponding panel.

Accessibility Changes made