Hi, I have been researching and internally debating the topic evolution /intelligent design for a few years now. Through this researching I've become increasingly convinced that intelligent design is a travesty based on little more than pseudo-science and rhetoric. Up till recently my biggest qualm with evolution was, as creationists put it, the lack of transitional forms in the fossil record. My second reason for doubt is the very mechanism evolution uses to function- random mutation- which as many biologists acknowledge is usually, if not always, harmful. Moreover, it's not as though our DNA itself has any awareness of the external environment around us aside from maybe sensitivity to temperature or PH. (That second reason for doubt is besides the point of my question)
I've recently researched transitional forms in the fossil record and have learned that there are in fact (contrary to what creatonists will tell you) transitional forms in the fossil record. However, if evolution is still occuring to this day, how come there are no transitional forms in existense today IE. fish with half formed limbs and such. I understand why the Australopithecines and early human ancestors went extinct, but I imagine there would be at least one living example of a clear transitional form in existence today. Any thoughts?
Let's have a lineation of species from A to C, with B as the intermediate transitional that you're seeking.
A --> B --> C
In hindsite, when we have all three species, it is easy to see that species B has some of the features of A that are different but not quite as different as C's so we can see that it is "in-between" them and can call it a transitional.
But if we're talking about modern species today, then we would be missing that C component:
A --> B --> ?
Without knowing what's comming next, and only having one end of the chain, we can't really show how B is a transitional.
Does that make sense?
That doesn't mean that there aren't any transitionals today, its just that we can't really show that they are without all the pieces indicating it as such (and we can't predict the future).
Every organism that leaves a descendant is transitional, in the same way that your father is transitional between your grandfather and you. The differences between ancestral species and descendant species only become obvious after many generations, so you don't look that much different from your grandfather (in a general sense) but going back a thousand generations or ten thousand, ancestor and descendant can look quite a bit different from each other.Your beliefs do not effect reality and evidently reality does not effect your beliefs. -Theodoric
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Go back a few hundred million years and look at the fauna flopping around and you'll see all sorts of thins, including an unremarkable semi-amphibious fish with legs - Tiktaalik roseae. It'd be a bit unusual but you can't recognise it as a transitional between bony fish and Tetrapods until you know that tetrapods are going to become a big thing and what features end up defining the group.
Pop back to the time of Archaeopteryx and it'll appear as one of a number of flying dinosaurs, sharing some features with its close relatives and having a few novel features. It isn't until you've seen a modern bird that you can identify those features as a patchwork of features of theropods and birds.
It might be that, in the future, otters become fully aquatic and displace the cetaceans at which point a future scientist would look back and point out the remarkable patchwork of features that otters have, and their clearly transitional nature. But until we know what life will be like in the future we cannot identify transitionals.
I think it is out of print, but maybe you could find a copy of After Man: A Zoology of the Future by Dougal Dixon. I think it will make clear, though it's entirely speculation, that we have plenty of "transitionals" around today.
However, if evolution is still occuring to this day, how come there are no transitional forms in existense today
There are, in fact ALL living things are transitional.
Let me put this a different way.
If you travel from Boston to Los Angeles, then the Mississippi river is a point along the way. It's a "transitional point" between Boston and LA.
However, if you set out from Boston without saying "I'm going to LA" and drive and come to the Mississippi River, you've gone the same distance, ended up at the same point.
If you then proceed on to LA, the river was transitional. If you go to Las Vegas, it was transitional, if you back track and go to Florida, it was transitional.
The waypoint is transitional no matter WHERE you are headed. It's just that we don't know where you are going to end up.
Creationists want to see a "transitional form" between something in the past and something in the future. Do you know the future? I sure don't.
The best answer to this question is "Okay, you present me with an example of the future animal, and I'll show you the living form that was transitional to it".
My second reason for doubt is the very mechanism evolution uses to function- random mutation- which as many biologists acknowledge is usually, if not always, harmful.
Actually, no biologists would acknowledge this because it's not true. The VAST VAST VAST majority of mutations are completely neutral.
Every person alive has mutations and is no worse the wear for it.
Now, of the remaining mutations, the harmful ones are FAR more obvious than the beneficial ones.
If you see someone who was born without eyes as a result of a mutation, you know it right away. If you see someone who has a mutation that makes him immune to heart disease from chlorestrol, you don't see it.
But, even setting all that aside, and going with the premise that most mutations are bad and only a very few are good - a very few is all that's needed. We're talking about billions of years. Tiny improvements add up.
I'd like to expand a bit on what you said, with the hope that Peter1985 will read on.
What we call transitional forms are not necessarily on the direct line of descent to today's species and it can be hard to tell for the vast majority of fossils. What they do retain are the traits that we recognize as being the primitive and derived features we expect to see in a transitional species since they likely diverged from that direct line or from species close enough to the direct line that they retain many of those features. They are the "cousins" on the family tree.
Consider otters. They are members of the Mustelidae family (mink, stoat, weasel, marten, badger, wolverine, skunk (??), ferret, etc.). All species are semi-aquatic. The sea otter rarely comes ashore.
Although we cannot predict the future evolution of any species, since any or all otter species might re-adapt to life on land, otters appear to be in transition from land to water environment.
Consider the pinnipeds, the seals, sea lions and walruses. These too, like the otters, are carnivores and closely related to land mammals in the suborder Caniformia, which includes bears, dogs, pandas, the Mustelidae, raccoons and coatis. They too seem to be in a transition between land and water. While the bone structure of their limbs is the same as any other carnivore, externally they appear as fins.
There's no reason to suppose that this fish will ever produce descendents that move onto the land, but it has one of the pieces of equipment that would help it to do so. It currently lives mainly in Tasmanian estuaries. But it has fins/hands which can be used to walk, and in one of those videos, it seems to handle its eggs.
Lack of transitional forms today is because of "the maintenance of stability within species." Richard Dawkins says, "Evolution has been observed. Its just that it hasnt been observed while its happening."
Lack of transitional forms today is because of "the maintenance of stability within species."
(1) Please demonstrate the lack of transitional forms today. Note that in order to do so it is necessary to examine their descendants, who do not yet exist.
(2) How does the "the maintenance of stability within species" account for (1) the transitional forms found in the fossil record (2) the Law Of Faunal Succession (3) the fact that species are observably not stable?
Richard Dawkins says, "Evolution has been observed. Its just that it hasnt been observed while its happening."
And Louis XIV said: "L'état, c'est moi", but I don't see why you would mention it.
Your question is like asking: "The prophet Muhammad is said to have has 14 million living descendants. So why is there no-one alive today with that many descendants?"
Unless the world is about to come to an end (which pace Harold Camping I think unlikely) there are almost certainly people alive today who will have that many descendants; but I am unable to identify them. Perhaps you yourself are such a person, but how would we know?
In the same way, if you come back in ten million years maybe the descendants of Wallace's Frog will have mastered true flight, in which can Wallace's Frog will appear to future naturalists to be the intermediate gliding stage between ordinary frogs and frogs with true flight. Or maybe it's an evolutionary dead-end and it won't.