Are all fossils “transitional”? A test rant.

All over the net I see people trying to defend evolution from the attacks of antievolutionists which is good. However when they do so using false or inaccurate arguments that is not so good. For example one of my pet peeves is a particular argument that I’ve seen commonly used to rebut antievolutionist claims that there is a lack of “transitional” forms in the fossil record which often goes something like this:

“You don’t know what you’re talking about, all fossils are transitional.”

Unfortunately this is simply not true. Not all individuals reproduce; nor do all species give rise to new species. In fact many (if not most) lineages in the history of life have led to dead ends. Think about it, if a fossil represents a species which did not give rise to new species, what is it transitioning to?

Of course part of the problem is the use of term “transitional fossil” since the word transitional implies that there is some certainty about specific lineages which is actually rarely the case in paleontology.

It is better to talk about “intermediate fossils” since this refers to morphological characters (facts) rather than hypothetical lineages.

For example Archaeopteryx is undeniably intermediate in form between dinosaurs and birds being a mixture of both dinosaurian and avian (and some in between) characters, this is a fact. The question as to whether or not the genus Archaeopteryx is itself ancestral to later birds would be a hypothesis which is 1) very difficult to test and 2) not one that all paleontologists who work on dinosaurs/birds necessarily agree upon.

So please, for the sake of my sanity (and for scientific accuracy), spread the word to stop claiming that all fossils are “transitional” and maybe encourage the use of the term “intermediate” instead.

End rant.

5 Responses to Are all fossils “transitional”? A test rant.

  1. [...] I suspect he’ll talk about antievolution stuff quite a bit, which will be good. He already has a good post on transitional fossils. [...]

  2. Dave S. says:

    I sometimes used the two terms interchangeably, always with the proviso that ‘intermediate’ or ‘transitional’ refers to the form, and does not necessarily imply a direct lineal ancestor/descendant relationship. Although I see where that can still be confusing. What do you think of the argument I’ve occasionally heard that ‘intermediate’ is still somewhat deceptive since it can imply that the form is in the middle, when in reality it may be closer to one or the other endpoint, and that yet another word like ‘interposed’ may be more appropriate?

    BTW, good luck on the new blog, and great shirt! Hope your wife is feeling better.

  3. Troy Britain says:

    Dave S.: What do you think of the argument I’ve occasionally heard that ‘intermediate’ is still somewhat deceptive since it can imply that the form is in the middle, when in reality it may be closer to one or the other endpoint, and that yet another word like ‘interposed’ may be more appropriate?

    Whatever is used will probably take some explaining. For example it needs to be pointed out more often that intermediate fossils are not going to be intermediate in all characters, rather they are mixtures of intermediate characters and mosaics of primitive and advanced traits, with characters from both the parent group and the daughter group. Archaeopteryx being a classic example. While it had some intermediate characters it was also a mix of “dinosaurian” characteristics and “avian” characters. Of course the distinction between what constitutes dinosaurian and avian has become more clouded with the introduction of so much new material from China. Oh the horror of having too many intermediate types!

    BTW, good luck on the new blog, and great shirt! Hope your wife is feeling better.

    Thanks and thanks.

  4. Oldfart says:

    While you are at it, explain “primitive” and “advanced” traits. Since it is also often said that later is more advanced than earlier assuming some kind of “direction”.

  5. Hi, I just felt like to write a quick note here to tell you that I really finding your blog,

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Connecting to %s

Follow

Get every new post delivered to your Inbox.