Many people, including eminent biologists, struggle with the concept that some life forms are more evolved than others.  It’s not particularly controversial to say humans are more evolved than Australopithecus africanus, because the latter is extinct, and thus humans are the product of an extra two million years of evolution.

Much more controversial is claiming that one extant life form is more evolved than another.  This is because many scientists view all extant life as not a linear chain of ancestors to descendants, but rather cousins who are all parallel forms of time tested evolutionary success.

When creationists say to biologists “if humans evolved from apes, why aren’t apes still evolving into humans?”, the biologists laughs at the creationist’s ignorance, and says humans did NOT evolve from apes.  Rather humans and apes share a common ancestor.

But what few biologists grasp is that humans really did evolve from apes (in the popular sense of the term).  True, we did not evolve from any extant ape like gorillas or chimps, but if we could clone our ancestors, most people would describe them as apes.

ape-to-man-evolution

Of course the scientist would say:

Well technically, the common ancestor is no more genetically related to modern apes than it is to a human.

That’s true if you measure genetic relatedness by neutral DNA, which, because it changes at a consistent rate, serves as a molecular clock measuring time since divergence from a common ancestor, but it’s perhaps false if genetic relatedness is measured by substantive DNA, which changes as a function of selection pressures.

Who is most evolved?

In order to determine who is more evolved than who, you need to look at the evolutionary tree.  If you’re the first branch, and you don’t do anymore branching, then you are less evolved than higher branches.

At the highest taxanomic level, there are just tree domains of life: Bacteria, Archaea, and Eukaryota.  Humans are eukaryotes and thus are more evolved than bacteria, which branched off prematurely:

Among eukaryotes, there are at least three major divisions: plants, animals and fungi.  Plants branched off the evolutionary tree first, making them less evolved than us animals:

Among animals, us chordata are most evolved:

Among chordates, us mammals are most evolved:

Among mammals, us primates are tied for the most evolved:

Among primates, “homos” are most evolved:

Among homo, we see that Homo Sapiens and Neanderthals are tied for most evolved:

Among Homo Sapiens, it seems Northeast Asians and Arctic Asians are tied for most evolved.

A genetic tree created from page 119 of L.L. Cavalli-Sforza's book "The Great Human Diasporas"

A genetic tree created from page 119 of L.L. Cavalli-Sforza’s book “The Great Human Diasporas”

Of course this is uncertain because it seems Sfroza somewhat arbitrarily divided humanity into nine races (I prefer a three race model).  A different classification scheme might have resulted in a different race being more evolved, though the same criticism applies to almost every phylogenetic tree.

Does more evolved mean superior?

Scholar J.P. Rushton is quoted as saying that from an evolutionary perspective, superiority can only mean adaptive value, if it even means this.  Humans are perhaps the most evolved animal on Earth and we are arguably the most adaptable, but there are also very unevolved life forms that are extremely adaptable too, like cockroaches for example.

But if evolution is all about trial and error, life that emerges later should, on average, be more adaptable than life that appears earlier, and yet cockroaches, one of the oldest forms of life, has stood the test of time.

How do we resolve this paradox?  One possibility is that the more primitive organisms benefitted from coming first and thus monopolizing the low hanging fruit: those ecological niches that were easiest to adapt to.  More complex newer life forms might be more adaptable in principle, but all the good real-estate has been taken.

 

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