You can choose to copy an animation layer using the Duplicate button, the contextual menu options, or the keyboard shortcuts.

To copy the animation layer using Duplicate:

1. Select the animation layers you want to copy.
2. In the Key Controls window, select a layer from the Layer menu to make it current. The current layer displays bright green in the Animation Layer editor.
3. Click the Duplicate button in the Animation Layer editor toolbar.

   The newly-duplicated layers appear above the current layer in the stack and contain the keyframes of the layers you copied.

To copy and paste the using the contextual menu:

1. Select the layers you want to copy.
2. Right-click one of the selected layers, then select Copy from the contextual menu. You can also select the layer and press Ctrl-C to copy it.
3. Right-click on the layer above which you want the new layer to appear, and select Paste from the contextual menu. You can also click a layer and press Ctrl-V to paste the new layer above it.

   The pasted layers appear above the current layer and contain the keyframes of the layer you copied.