Evidence For Evolution: Homology – similarities between creatures & Atavism

Similarities between creatures can be evidence for their having shared a common ancestor (which means if you go back through their parents generation by generation for millions of years you will get to parents that they both have in common as direct ancestors). Differences between organisms show the changes that have taken place over the generations that have passed since their last common ancestor.

Bellow you can see how Humans, cats, whales and bats all have the same basic forelimb bone structure that they share due to having a common ancestor:

From whales having homologous underlying forelimb structures to other mammals we can predict that they are more closely related to them than to other more similar looking organisms like sharks. Genetic evidence confirms such predictions with the DNA of a whale being more similar to a cat than a shark. Sharks and whales appear more similar due to both having evolved in adaptation to the ocean environment they both have in common.

Comparing organisms at earlier stages of development reveals even more homologies, such as; all vertebrate embryos have a well structured throat pouch and a tail located behind their anus:

Learn more about Homology: http://evolution.berkeley.edu/evolibrary/article/similarity_hs_01

Bellow is an image of a Dolphin with 4 fins. Dolphins do not normally have rear fins, the trait having disappeared from the Dolphin lineage. This indicates that even though the genes for building the additional fins are no longer being expressed they are still present in Dolphin DNA and can occasionally still be expressed. A random mutation could not produce perfect fins. This can happen as DNA is not expressed evenly (some genes are expressed more than others and some not at all).

Learn more about the reappearance of disappeared traits: http://en.wikipedia.org/wiki/Atavism

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Comments to “Evidence For Evolution: Homology – similarities between creatures & Atavism”

darwinismrefuted.com on October 4th, 2009 at 11:26 am

Homology Theory. Evidence for common ancestry or a common design?

Homology is a tautological argument, advanced on the basis of no other evidence than an apparent physical resemblance. This argument has never once been verified by a single concrete discovery in all the years since Darwin's day. Nowhere in the world has anyone come up with a fossil remain of the imaginary common ancestor of creatures with homologous structures. Furthermore, the following issues make it clear that homology provides no evidence that evolution ever occurred.

1. One finds homologous organs in creatures belonging to completely different phyla, among which evolutionists have not been able to establish any sort of evolutionary relationship;

2. The genetic codes of some creatures that have homologous organs are completely different from one another.

3. The embryological development of homologous organs in different creatures is completely different.

Check the links bellow to examine each of these points one by one.

http://www.darwinismrefuted.com/myht_of_homology….

[youtube pMVBFJCqFXc http://www.youtube.com/watch?v=pMVBFJCqFXc youtube]

cwar068 on October 5th, 2009 at 7:21 am

Also, to say that there are no fossils showing primitive (in an evolutionary sense) characteristics is not true either. Textbooks on Biology are full of references to them.
Here’s a list of fossils which help us understand our own evolution:

<a href="http://en.wikipedia.org/wiki/List_of_human_evolut…” target=”_blank”>http://en.wikipedia.org/wiki/List_of_human_evolut…

Here is some info from wikipedia on someone from your video that I chose at random:

"John Corrigan "Jonathan" Wells (born 1942) is an American author and a prominent advocate of intelligent design.[1] A member of the Unification Church, Wells wrote that the teachings of church founder Sun Myung Moon, his own studies at the Unification Theological Seminary and his prayers convinced him to devote his life to "destroying Darwinism",[2][3] a term which intelligent design proponents often use to refer to the scientific consensus on evolution[4] and which he describes as the theory that various species developed as a wholly natural process "without G"

http://en.wikipedia.org/wiki/Jonathan_Wells_(inte...

cwar068 on October 4th, 2009 at 11:05 pm

Well a quick look at an example of a tautological argument in wikipedia gives this quote by Bush:

"It's no exaggeration to say the undecideds could go one way or another."

Above we see the same idea given in different words.

Now I argued that "Similarities between creatures can be evidence for their having shared a common ancestor".

"Similarities between creatures" and "evidence for their having a common ancestor" are not the same thing. This is a statement which can be investigated, whereas it would be pointless to investigate whether undecideds could go one way or another as they could do so by definition.

Your claim that no homologous traits have been identified is totally false.

Creationists constantly fabricate arguments against evolution which rely solely on the ignorance of people to be believable.

My major reference for this post was Biology (Campbell & Reece, 2008) which is a mainstream introductory text used for Biology (including for medical students) at Universities around the world including the University of Auckland.

cwar068 on October 4th, 2009 at 11:06 pm

I included a link for a site by Berkley University where you can actually learn about homologies.

The video, which is American Christian creationist propaganda, is trying to confuse people with talking about analogies, and past mistakes, without explaining them.

Analogies occur when traits have evolved separately through parallel evolution and do not indicate shared ancestry. For example the flippers of whales and sharks are analogous, however they evolved separately. The whale is descended from land based animals related more closely to birds than to fish. However, even though the forelimb of a mammal can be adapted through evolution to be used as a flipper, because of the common oceanic environment that whales share with sharks, it is far less likely that the underlying bone structure common to all mammals evolved independently in the whale lineage.

Whales in fact have hind legs and pelvises within their marine bodies. Why do you think Allah would have put hind legs and pelvises in organisms he intended to live in the water? http://evolution.berkeley.edu/evolibrary/article/... (picture at bottom of page)

cwar068 on October 4th, 2009 at 11:06 pm

Here's a quote from Britannica Online Encyclopaedia:" in biology, similarity of the structure, physiology, or development of different species of organisms based upon their descent from a common evolutionary ancestor. Homology is contrasted with analogy, which is a functional similarity of structure based not upon common evolutionary origins but upon mere similarity of use. Thus the forelimbs of such widely differing mammals as humans, bats, and deer are homologous; the form of construction and the number of bones in these varying limbs are practically identical, and represent adaptive modifications of the forelimb structure of their common early mammalian ancestors. Analogous structures, on the other hand, can be represented by the wings of birds and of insects; the structures are used for flight in both types of organisms, but they have no common ancestral origin at the beginning of their evolutionary development. A 19th-century British biologist, Sir Richard Owen, was the first to define both homology and analogy in precise terms."