Analogous vs homologous

nygreenguy wrote:

Category number 1 (Hierarchical Taxonomic Classification) is a good example of a pattern that can, of course, be explained by special creation. Linnaeus did just that. But Darwin a century later explained the same set of ordered relationships between organisms as being the result of divergent evolution and shared ancestry. More important, though, is the fact that organisms created de novo need not show varying degrees of similarity to one another. Each creature could be constructed completely differently from every other creature and made from very different materials. Humans need not look like apes, but we do. We show varying degrees of similarity to them and we are made of the same stuff. We could have been created this way but we must look like this if, indeed, we have evolved and diverged from a relatively recent common ancestor.

The article doesnt say taxonomy is necessarily the evidence, rather the fact that the similarities which taxonomy was based upon reveals to us patterns which can be explained by evolution. It is a way of answering “Why do this organisms look so much alike”.

And also it states, “Category number 1 (Hierarchical Taxonomic Classification) is a good example of a pattern that can, of course, be explained by special creation“.

So yes, they can be analogous or homologous, but its quite easy to separate the traits.

Can you give me an objective method to which something can be determined to be analogous or homologous? I have heard of no such method. Instead, it’s a subjective call.

How do we decide if a character is homologous or analogous?

First we hypothesize them to be so. Then we look at the preponderance of other characters to test our hypothesis. Cladistics gives us a framework in which to do this. Cladistics was basically invented by Willi Hennig who was a specialist in flies. Here is a link to a site that describes in detail and in a different way how we do cladistics:

In cladistics we assume that we wish to focus on genealogical relationships and that our classifications of taxa should depend on our analysis of these genealogical relationships. Of prime importance is the historical sequence in which the taxa descended from a common ancestor. Hence, our cladistic hypotheses are based on our estimate of the historical sequence of the acquisition of novel characters.

It would seem to me he stuck to the morphological classification and creation had nothing to do with it.

Here is what Carl Linnaeus wrote:

As he wrote in the preface to a late edition of Systema Naturae: Creationis telluris est gloria Dei ex opere Naturae per Hominem solum — The Earth’s creation is the glory of God, as seen from the works of Nature by Man alone. The study of nature would reveal the Divine Order of God’s creation, and it was the naturalist’s task to construct a “natural classification” that would reveal this Order in the universe.

Even then, this is almost 300 year old science. Why would we try to use the views of a 300 year old scientist on creation today?

Why is it used as the first evidence in Humans As a Case Study for the Evidence of Evolution?

McCulloch wrote:

otseng wrote: You tell me. Does human evolutionary theory posit that humans arose from one couple?

No, it does not.

Then what does it state?

otseng wrote: And if human evolution is indeed a fact, it should be quite simply to prove, without simply relying on the vast majority of scientists in the field agreeing with it.

If general relativity is indeed a fact, it should be quite simple to prove it, without relying on difficult mathematics, right?

False analogy. My comment was directed at SailingCyclops stating that we should believe something simply because authorities state that it is true.

I have no problem demonstrating that something is supported by mathematics. But simply stating that something is true because authorities says it is true is not sufficient by itself.

otseng wrote:There are features common in all primates which appear to be homologous, pointing to a common origin.

As I pointed out earlier, there is no objective method to determine if something is homologous.

If the god created every species separately, he seems to have done it in a way that appears to be evolutionary.

It may appear to some that way. It may not appear that way to others.

He did not borrow a useful feature from one apparent line of descent and fuse it into another line that might need it. Whales and dolphins with gills. Why not?

We see many examples of features where it did not originate from a common ancestor.

Some include:

– Koalas of Australasia have evolved fingerprints, indistinguishable from those of humans.
– Marsupial sugar glider and squirrel glider of Australia are like the placental flying squirrel.
– Opossums have evolved an opposable thumb, a feature which is also commonly found in the non-related primates.
– Microbats, toothed whales and shrews developed sonar-like echolocation systems used for navigation and for locating prey. DNA study has shown that echolocation in two types of bats, megachiroptera and microchiroptera, came about independently.
– Platypus have what looks like a bird’s Beak (hence its scientific name “Ornithorhynchusâ€�), but is a mamm
– In an odd cross-species example, an insect, the Hummingbird Hawk-moth (Macroglossum stellatarum), also feeds by hovering in front of flowers and drinking their nectar in the same way as the above mentioned birds.
– Oilbird like microbats and toothed whales developed sonar-like echolocation systems used for locating prey.
– The Antifreeze protein of fish in the arctic and Antarctic, came about independently.
– The smelling organs of the terrestrial coconut crab are similar to those of insects.
– Silk: Spiders, silk moths, larval caddis flies, and the weaver ant all produce silken threads.
– Swim bladders – Buoyant bladders independently evolved in fishes, female octopus and siphonophores such as the Portuguese Man o’ War.
– Venomous sting: To inject poison with a hypodermic needle, a sharppointed tube, has shown up independently 10+ times: jellyfish, spiders, scorpions, centipedes, various insects, cone shell, snakes, stingrays, stonefish, the male duckbill platypus, and stinging nettles plant.
– Bioluminescence: A symbiotic partnerships with light-emitting bacteria developed many times independently in deep-sea fish, jellyfish, and in fireflies and glow worms.
– Hallucinogenic toxins: Plants as diverse as the peyote cactus and the ayahuasca vine produce the same form of chemical toxin to deter predators.