From Wikipedia: A transitional fossil or transitional form is the fossilized remains of a life form that illustrates an evolutionary transition. It can be identified by having certain primitive (plesiomorphic) traits in comparison with its more derived relatives, such as defined in the study of cladistics. "The Missing Link" is a popular term used for transitional forms.
A popular term to designate transitional forms with is "the missing link". The term is especially used in the regular media, but inaccurate and confusing. This is partly because it implies that there was a single link missing to complete the picture, which now has been discovered. In reality, the continuing discovery of more and more transitional fossils is further adding to our knowledge of evolutionary transitions. The term probably arose in the 19th century where the awaited discovery of a "missing link" between humans and so-called "lower" animals was considered to be the final proof of evolution. The Australopithecus afarensis fossil (more commonly known as "Lucy") is seen as a key transitional fossil.
This is a very tentative list of vertebrate transitional fossils (fossil remains of a creature that exhibits primitive traits in comparison with more derived life-forms to which it is related). An ideal list would only recursively include 'true' transitionals, i.e. those forms morphologically similar to the ancestors of the monophyletic group containing the derived relative, and not intermediate forms. See the article on transitional fossils for an explanation of the difference with intermediate forms. Since all species are supposed to be in transition due to natural selection, the very term "transitional fossil" is essentially a misconception. But the fossils listed represent significant steps in the evolution of major features in various vertebrate lines, and therefore fit the common usage of the phrase.
- Fish to Amphibians
7 comments:
I just happened to read about that transitional whale-type animal yesterday. It makes you wonder about the willful ignorance some people have when it comes to declaring things about the fossil record. I'm related to a very obnoxious ID guy who says "show me one transitional fossil!" What's the point, when he won't accept any answer given to him.
Andrea, a long time ago, when I was a teenager and going for a short while to a Baptist church (my parents decided to try that religion for awhile), my husband who was my boyfriend at the time (and also a Presbyterian at the time and attending a catholic college-prep high school), was debating the pastor about evolution. The pastor gave him some pamphlets that were against evolution, and he wanted my husband to read them and my husband said sure he would read them, but wanted the pastor to read his book on evoltuion and the pastor said "absolutely not". My husband still read the pamphlets and again tried to debate the pastor and wanted to present the scientific evidence for evolution and again the pastor would not listen. I guess it was too big of a threat to his faith or something.
Off topic...how are the kiddies? I bet the baby has grown a lot already!
Also, why did you put your blog on private?
I put the other one on private because I haven't had the motivation to write much there, and partly because I got it off my chest for the time being...you know?
The boys are doing well. My oldest just turned 6, and the baby is about 4 months old now, and just as fiesty as his parents. He's also doubled his birth weight already.
andrea, I do know what you mean about getting things off your chest. I guess I keep this blog going because I have so many people who link here, and who still read (more than 100 visitors per day) and recently went past the 30,000 visitor mark. I know this blog is a "hodge-podge" of subjects...but just a bunch of stuff I think about or find interesting. I like your "andrea after hours" blog very much.
*love back atcha* I like this blog too, and I appreciate that you stick with it, consistently posting so many cool things.
I'm like you in that I have many different interests, but after a day of household chores and watching these boys, the most I have the energy to do on my blog is comment about a movie or whatever. Me and my husband usually watch a movie every night, and during the day I try to read while the baby naps.
More than 100 visitors every day! I'm lucky if I get 10 a day :) lol
I was averaging about 40 or 50, but seem to have dropped off lately.
As for evolution, I would argue that if evolution were not true, then you would not expect that there would be mammals like whales and dolphins that live entirely in the water and have to surface to breathe.
I have proof for evolution right here:
http://anexerciseinfutility.blogspot.com/2007/06/proof-of-evolution.html
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