Monday, June 22, 2009

Side-by-side Model of Selection Proper and Improper

Often when debating people who do not accept evolution, it is clear that they don't accept it because they don't understand it. The version of evolution they carry in their head is so warped and absurd, I'd reject it too. Typical are comments like this from Raymond at #67:

"The question, then, is if a new species were to result from some arbitrary genetic mutation, with what does that new species procreate? Even if the assumption is that a new species does not appear suddenly in one individual but rather evolves over a long period of time, problems remain. At some point the first of the new species which could not interbreed with its forebears most have appeared so with what did it then procreate? Also, if it happened over a long enough period of time for evolution to have worked its slow magic, then why do we not see more evidence of it in the fossil record?"

Raymond is working from a common misperception, that of the "hopeful monster", a creature that mutates so far from his parents that he cannot breed with them or any other members of his former species. This is the fiction of many a science fiction story (eg X-Men), big on shock and gore value, small on science. It is represented on the right in the exhibit below. The way speciation actually works is shown on the left:

As we can see, there is no point where the group on the left cannot breed with the previous generation, because the change from one generation to the next is very small. It is only the accumulation of many such changes over time that eventually produces a new species. One wonders how many people would still reject evolution if they actually had an accurate picture of what it is.

Hat Tip: PZ Myers


parakeet said...

I wiki'ed on "Hopeful Monster" because I wasn't sure if I understood the term correctly. There, I found the following surprising statement by Stephen J. Gould: "As a Darwinian, I wish to defend Goldschmidt's postulate that macroevolution is not simply microevolution extrapolated." I can't tell for sure if that's a position that contradicts "there is no difference between macro and micro evolution except degree."

On a different note, I decided on a whim to google on "evolutionists who became creationists" to see if any "experts" went that route. I found these two sites:


Though many of them are/were PhDs, I don't know anything about them to state an opinion about their knowledge of evolution. The lists aren't long.

ScienceAvenger said...

History suggests it is wise to view quotes from scientists that appear to support creationist arguments with great skepticism, given the predilection creationists have for plucking phrases out of context and presenting them as meaning the opposite of what they originally were written to mean. If the quote contains an ellipses, the odds of it being so approaches 100%.

Gould was no friend to the creationists, not while he was alive to defend himself anyway.

The Phds of science-deniers are usually not in the relevant field being denied. Indeed, that is one of the hallmarks of crankery. It makes no difference how you slice the data, if an authoritarian argument is to be made, the creationists lose 100:1, at least.

parakeet said...

This post might engender a different one about how science defines "species." The ability to mate and reproduce is often the key indicator of a specie, but this often breaks down. Even a sheep and a goat are known to have offspring, if rarely. "Species" is tricky to define, indeed.

Sharon E. Dreyer said...

Since Darwin's theory is just that, "a theory," it's a shame that so many people are so very completely brain-washed and believe that it is "gospel." As a theory, it has always amazed me that evolution, creationism, and the other theories or theologies aren't all taught in our school systems. Some scientists are so arrogant! An open mind that is rational is a wonderful thing!

ScienceAvenger said...


Yes, "species" is something of a nebulous term at the intersections, but since evolutionary theory doesn't depend on there being a crisp division, it's really just an academic debate.


The brainwashing is that which is done to persuade people that scientific theories are "just theories" (they aren't), that scientists take it as gospel (they don't, thus all the research), that evolution is a theology (it isn't, no gods, no magic, no heaven), or that scientists are arrogant to acknowledge these things. A mind that denies them is so open it is empty.

Troublesome Frog said...

Sometimes, all you can do is quote Bobby Henderson:

I think we can all look forward to the time when these three theories are given equal time in our science classrooms across the country, and eventually the world; One third time for Intelligent Design, one third time for Flying Spaghetti Monsterism, and one third time for logical conjecture based on overwhelming observable evidence.

alex said...

This is not a comment on "hopeful monsters," but a difficulty about something I've thought about. In the long line of minute changes taking place within organisms, does that mean that the method of birth changed gradually, too? The reason I ask is because an animal can give birth via an egg or not, inside or outside the body. It has a binary feel to it without much seeming room for gradations. It's as if somewhere along the line, an animal was born via one method and had to have a child born via a different method. Sounds crazy, but the alternative doesn't seem so plausible either.

ScienceAvenger said...

Alex, your argument is a perfect example of what is commonly called "The argument from personal incredulity". It amounts to "I, personally, don't see how this could be true, therefore it isn't". Scientific value = 0. Reality is not limited by our imaginations.

Now sure, scientists should and do ask such questions. That's what forms the basis of research - going to look for the answers (you know, the work the IDers expect everyone else to do for them). Laypeople who ask such questions, on the other hand, are rarely really interested in the answers, given how easily some of the are to be found in 10 minutes with google.

As it happens your example spawns one such scenario immediately in my imagination. Being born internally inside the body with ever decreasing egg thickness to zero and hence nonexistence. But worse than that, if you look at a shell as just a part of the body being born, it doesn't seem to have any more of a binary problem than anything else we are born with.

alex said...

"Alex, your argument is a perfect example of what is commonly called "The argument from personal incredulity"."
No SA, it was a thought -- inviting an explanation -- not an argument.

I'm a layperson who is VERY interested in these answers. I appreciate your attempt in the 3rd paragraph.