The video suggests this Wallace Line exists because it was once a separate piece of land, that has evolved differently, therefore each side is uninhabitable to animals / fish on the other side.

Although I do agree, somewhat, I dont think this explains why this invisible line exists so strongly.

Most people live and die in the town they were born. But they can move to a different town or city or country, but they don't. Many people dream about it, but they don't. Few escape. In theory nothing is stopping them, physically it seems like we all have the option to choose. And it appears as though we choose to stay or go or move. I think humans behave like this because they locked into their area they live, because each area is broken up into invisible boundaries. The area is defined by a common resonance. The resonace is created by the culture / language/ types of people / wealth / poverty / clubs organisations in that particular area. These areas are created into countries, counties, states, towns villages areas blocks streets etc. Think about it, the area you live in. How often do you visit the area opposite across town. Most of us don't. Except maybe to visit place of work. In theory there is nothing stopping us from exploring an area across town but we don't. Its because the resonance of that area locks us out, and doesn't match the resonance or frequency we have become accustomed to. Sometimes people find themselves in the wrong area. Their resonance or frequency doesn't match the area they live in. This will push those people out and they end up moving.

This Wallace line is the same. Its a matter of resonance/ frequency. The fish in the sea literally are unable to cross this invisible line even though there is no physical line stopping them.

I've observed this even walking past a certain street, especially a cul de sac ( dead end roads). A cul de sac has its own unique resonance that even a person of a neighbouring street would find it uncomfortable to enter. It would require force to cross the invisible line that creates the area of a cul de sac. Similar to the Wallace Line.

We think we can go anywhere, we are governed by free will, power of choice, do I go here? do I go there? do I choose this? do I choose that? Do I vote for Reublican? Do I vote Democrat? Its all a matter of resonance. Does your frequency match. If so then you will. If not then you won't.

Back to the Wallace Line. Its a matter of resonance above all else. Physically the two sides may now begin to look physically similar. Because the two sides aren't separated anymore as thry once were, in theory the fish would be able to survive on both sides. But the fish won't cross the line because their resonance doesn't match. You'll probably get a few random fish that some how have a different resonance the black sheep of the herd. They may break away from the pack and cross the line. Eventually over time if they are able to establish themselves in the different area they will slowly begin to change the reonsnce of the area. Slowly more fish whose resonance closely matches the resonance of the new area migrate. And over time the chsracteristics of the Wallace line changes. But this could take many millennia or even millions of years.

Realising that there are invisible areas all round us that physically stop us from entering (even though there is no physical barriet) means that once we are aware of this we could work on fundamentals that change our resonance. And then suddenly we are able to enter the new area with ease and smoothly.

Fundantally changing our resonance if done correctly is a very easy thing to do. Eg. Take up a new sport that is popular in the area. Make a friend in that area. Learn the language of that area.

You could start as simple as take a walk into that area and become familiar with the roads. Or drive into the area with the intention to learn the road layouts. Try driving into a cul de sac. Its odd. You will feel the difference in resonance. Slowly over time, the resonance become part of you and all of a sudden it's not so hard any more.

What the point of all this? Once you have collected the resonance of that area, the all of a sudden people from that area will become attracted to you. Opportunities that were isolated to that area or to the people of that area suddenly become accessible to you. You become more integrated with different areas. And you may come to a point where you don't belong in your current area any more and so you end up moving. But this move become smooth rather than forced.

Any way this Wallace Line you posted very fascinating. We have our own invisible wallace lines all round us. Sometimes to our detriment. In most instances we don't have to spend our whole lives staying on one side of these invinsible lines. We often wonder why we can't do more with our lives. Its all about identifying the Wallace Lines in our life. And working towards crossing these barriers smoothly, easilly, to unlock more opportunity. There is a big whole world out there. Go for it and explore it, who knows what life may bring.