Where’s the crocoduck? Where’s Homo webbed-feet?
Chapter 6 (“Missing Link? What Do You Mean, ‘Missing’?”
and chapter 7 (“Missing Persons? Missing No Longer”
of Dawkins’ latest book (The Greatest Show on Earth: The Evidence for Evolution) tackle the myth of . . . you guessed it: the flagship gap otherwise known as the SS Missing Link.
That boat don’t float. I found a few of Dawkins’ points particularly illuminating, including these two.
1) Biological transitions are never immediate (hardly never?), often occurring over many thousands of years, with innumerable, subtle “intermediate stages” between what we recognize as before and as after. Whether opponents to evolution demand to see “a monkey give birth to a human” (that actually happens every day, at least in the colloquial) or a fossil of a half-carrot, half-bird, or some seemingly more reasonable demand, they are confusing snapshots of the moving picture of evolution for endstates. And revealing an ignorance of how evolution works.
On page 203 Dawkins writes:
“Nobody seriously believes there are two kinds of people, children and adults, with ‘no intermediates’. Obviously we all understand that the whole period of growing up is one long exercise in intermediacy.”
Consider a family photograph album with a number of missing pages. Are we supposed to believe that the son from page 1 “magically” transformed into the man on page 31, the daughter on 2 to the woman on 32? (Was that a sexist numbering?) Crazy! Or maybe not.
It is as if creationists, when examining the photographic record, demand, “Where are the photos of the baby boy with a full beard? Where’s the infant girl with double-Ds and pubic hair? Where are the missing transitional forms that strike me as obviously transitional!”
This sentence from the book is a real kicker.
“The changes that take place within an individual’s lifetime, as it grows up, are in any case much more dramatic than the changes we see as we compare adults in successive generations.” p. 205
Oh, snap!
Evolution is a messy affair. The well-educated and rational don’t expect to see a clear, distinct step by distinct step progression from simpler to more complex forms. (E.g. Step one, boy without a beard, step two, boy with a moustache, step three, boy with beard and moustache.)
2. Evolution is no ladder with representational species as rungs and a designated endpoint.
Although it may feel right to project a meaning onto evolution; it is mistaken. Manifesting extreme species-centrism, many people portray life as progression up the ladder of biological forms — slime, fish, rodents, monkeys, apes, and surprise! our kind — as a sort of preordained progression.
So those ancient fish with a proclivity for crawling in the mud at water’s edge, they did their part in providing the scaffolding that led to me. Thanks fish!
If nature had a motto, it might be, “what works, works.” Sounds tautological, but it’s true. In a sense, it is only tautological when we expect a greater meaning, a purpose.
So no, evolution is not about life progressing steadily up a ladder, progressively moving toward the godly ideal: which coincidentally is human-like. Talk about tragically narrow-minded.
How’s this for a startling and humbling evolutionary fact:
“A horse’s foot is simpler than a human foot (it has only a single digit instead of five, for example), but the human foot is more primitive (the ancestor that we share with horses had five digits, as we do, so the horse has changed more.” p. 157
Similarly, within a genus of species, forms have evolved with eyes only to later lose them to one degree or another (such as in the case of cave-dwelling fish and reptiles). What kind of ladder is that?
I came away from this section of Dawkins’ book with the insight that the idea of a missing link is a substantially bogus concept. First, because change is gradual and of degree, and second due to the expectation of inevitable advance.
I’ll end with a quote I particularly enjoyed.
“Think about the first specimen of Homo habilis to be born. Her parents were Australopithicus. She belonged to a different genus from her parents? That’s just dopey! Yes it certainly is. But it is not reality that’s at fault, it’s our human insistence on shoving everything into a named category.” p. 195
Words. Though they are fantastic tools, they do have limits.
There are billions of different possibilities for the formation of the solar system, for example, but the solar system of today, is the solar system that we see today, because none of those other possibilities ever occurred. Jupiter could have gathered more matter and became a secondary star, but that never happened, which is why it isn't. 
