It’s a well-known fact that dinosaurs and other life forms have died off and been replaced at the top of the food chain from time to time. Temperature is often cited as the culprit for such die-offs, since the Earth has been through hundreds of so-called “ice ages”. In fact, it can be shown that ice ages are the norm, rather than the exception on Earth. But perhaps a little more depth of analysis is needed.

Consider: most places on Earth, the daily temperature span from coolest to warmest during a day is some tens of degrees Fahrenheit. So it’s reasonable to assume that dinosaurs, like any other life on this planet, had a tolerance for this kind of temperature variation. Careful tallying of mean temperature variations from ice age to thaw shows than mean temperatures between such events were not that extreme. Let’s say ten degrees Fahrenheit from ice age to thaw, just on average across the globe. This shouldn’t be enough to extinguish any species. Moreover, dinosaurs were not constrained to specific locations. They were free, as with any species, to move about on the globe from colder to warmer climates. And at the equator, the temperature variations between ice age and thaw would be at their least. So at the equator, any die-offs due to temperature would have been unlikely at best.

And yet dinosaurs went more or less extinct. It would seem that climate, in terms of temperature, was not the reason. But if not temperature, then what?

One possibility is atmospheric composition. The percentages of oxygen (necessary for almost all surface life forms on Earth), are known to have varied over time for Earth. Today, oxygen makes up 21% or so of our atmosphere. But what if, during the time of the dinosaurs, the oxygen content was considerably higher? I’m not a climate scientist and I don’t have access to their historical climate data. But I do know that oxygen concentrations have varied over time. And what if the oxygen concentration was much higher during the time of the dinosaurs? And what if this is the exact factor with allowed the dinosaurs to exist and thrive in the first place? If so, then a drop of oxygen could have effectively suffocated the dinosaurs. It’s worth noting that during the period of dinosaur dominance, the major life forms on the planet were far larger than anything seen on land today. (The ocean is exempted; huge life forms still exist in the ocean today, just as they did then, though the dinosaurs who lived underwater also died out.)

But if this were true, then it stands to reason that the smaller dinosaurs would win out in the game of evolution, needing, as they would, less oxygen. If this were the case, then we ought to see reptiles larger than what we see today, but smaller than the large dinosaurs of the past. And a drop of atmospheric oxygen wouldn’t have as profound an effect under the oceans, yet those dinosaurs died as well.

So oxygen concentrations might have been the cause of mass extinctions, but it seems a little unlikely.

Let’s step back a moment and look at life on Earth. The theory of evolution is being eroded daily. Even Darwin questioned it after he wrote it. It sounds good, but the fossil record doesn’t seem to support it. We can see that a species may appear to follow another in form, but we don’t see intermediate species in the fossil records. That is, “missing link” species simply don’t appear to have existed. “Evolution” as such, would appear to have taken place in large jumps, which tends to invalidate the theory. But if evolution was not the cause of the diversity of life on Earth, what was?

Let’s step back even farther. Consider that the galaxy is full of life. That’s not an unreasonable assumption, all things considered. Let’s also consider that much of the life in the galaxy is older than that on Earth. This isn’t unreasonable either. It’s not unreasonable, for example, to consider that half the life in the galaxy is older than Earth’s, and half the life is younger. That may not be the case, but it’s at least reasonable to assume that a great many of the galactic life forms are older than us. If so, then it also stands to reason that they would have formed alliances, federations, and governments which spanned multiple star systems. So a confederation of star systems could easily exist which includes our solar system. In fact, such a thing is likely. It would be a federation of planets under one administrative body. That body would consider that Earth was under their direction and/or protection. Again, not unreasonable.

Now if that were true, it stands to reason that they would have something to say about the life on this planet. What form it took, how plentiful it is, etc. Also consider that any life form older than ours would have sufficiently capable technology to produce life forms tailored to certain environments and certain dictates. Companies might exist whose business it was to construct life forms according to the dictates or requests of some government. We already do this now. Most of our edible crops today are the result of genetic manipulation, whether done in genetic labs or by farmers crossing one strain of a plant with another to produce a third strain with preferred characteristics. In this scenario, a government could pay a company to generate various life forms to populate a planet. If you think this is just too fantastic, consider some of the odder species on this planet, like the duckbill platypus. If there was ever a “joke” species, that would be it.

This scenario would explain species diversity on our planet. A species is specified. It is designed and “implanted” on Earth. Then word comes down that the wings should be longer or the tail should be shorter or whatever. The company takes the matrix (DNA and such) of the existing species, and engineers it for the new specifications. Again it is inserted on Earth. It resembles the older species in some ways, which is clearly its ancestor, but there is no “bridge” species which connects the two. It is engineered.

So let’s just postulate that some types of life would simply not accommodate real intelligence. Let’s say that intelligence required the proper organs to enable speech. And the proper physical structure to enable constant tool manipulation, like upright posture and opposable thumbs. Let’s say that the ideal design for intelligent life is bipedal with opposable thumbs and speech organs in place. Dinosaurs wouldn’t fit that bill. Bears wouldn’t. Cats wouldn’t. Lions wouldn’t. But humans would.

So let’s say that Earth was originally populated with a bunch of primitive species which were suited to our atmosphere but not intelligence. Dinosaurs were elected, and the Earth was populated with them. Millions of years later, the government dictates a change of policy. Instead of being populated mainly with dinosaurs and other huge life forms, they want mammals instead, along with a single intelligent life form. So the company(ies) go to work and engineer life forms according to the new policy, and implant them on Earth. All is well.

Well, maybe not quite. Let’s say it’s known that huge lizards and mammals don’t mix will. Let’s say the government decides they want to give the new life forms the best chance possible to survive without really having to fight off massive enemies. So perhaps the same companies which design species to order also offer a service to remove species from a planet where they are no longer wanted. So they come here and more or less destroy any members of “forbidden” species. Like the dinosaurs. Dinosaurs disappear quickly (which they did) and humans and mammals are free to expand and extend across the whole surface of the planet.

Sounds far fetched, but if you really think about it, it makes a lot of sense. Did it happen that way? I don’t know. But if you fit it into what seems to be a realistic history of this sector of the galaxy, it’s not a bad explanation. And it certainly does fit with the facts as we see them.

Science seems to want to ignore real life sometimes, assuming that everything which happens is devoid of politics, and anything it can’t directly prove. But a lot of things probably exist that we can’t prove. Yet logic would seem to dictate that, as things are on Earth, so they are in the greater galaxy. And so there would be intersellar governments, interstellar alliances, interstellar federations, interstellar companies and the like. It may well be that there isn’t a speck of territory in this galaxy which isn’t claimed by one or more confederations or governments. There may even be (and probably are) wars which take place to settle disputes over who or what own which solar systems in various parts of the galaxy, just as there are here. And if governments have the power to claim certain parts of the galaxy as their own, then they certainly have the power to dictate what type of life exists on member worlds. And it’s almost certain they’d have the engineering expertise to make their dictates a reality.