You can "drag" the last frame to the first frame ... but ...

Sometimes you can miss 1 or 2 elements in the "studio" and get unexpected results.

I would recommend the following method.
It is foolproof.
I know ....................... 'cuz I use it. ...... :o)

---

1. Go to the last frame ...
   [menu] "Edit" ---> "Memorize" ---> "All"

Now ...

2. Go to the first frame ...
   [menu] "Edit" ---> "Restore" ---> "All"

Then ...

3. Go to frame two and "drag" a "window" around frame 2 to the last frame in the animation ... and make sure you INCLUDE EVERYTHING listed, cameras, lights, etc.

Now ...

4. Just hit "Delete." ................ all gone!

---

Now you have a "clean slate" with the first frame defined and you are ready for your new animation.

Note: The 1st frame in your new animation is now IDENTICAL to the last frame in your old animation ...

So ...

If you put the two animations together,
you will get a pause or "jerk,"
because you now have 2 identical frames, i.e.,
---> the last frame of the 1st animation

• and -
  ---> the first frame of the 2nd animation.
  (See Note below)

NOTE:
*If you plan to "join" the animations together:
Make sure you delete either,
... the last frame (in the 1st anim.)

• or -
  ... the first frame (in the 2nd anim.)*

If you don't plan to "join" the animations together, it doesn't matter.

cheers,
dr geep
;=]

Remember ... "With Poser, all things are possible, and poseable!"

cheers,

dr geep ... :o]

edited 10/5/2019