1. Comment #396744 by vega on July 15, 2009 at 12:23 pm

So images such as this are contributing to the misunderstanding? Any new image ideas?



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2. Comment #396745 by Ignorant Amos on July 15, 2009 at 12:23 pm

another excellent piece

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3. Comment #396753 by Steve Zara on July 15, 2009 at 12:43 pm

That was excellent. I loved the mention of humans as just another African Ape, which, of course, we are.

I think the "why are there still chimpanzees" question has another meaning than the assumption that we evolved from chimps. I think that other meaning is "why are there still apes which are different from us, and apparently more primitive - why didn't all of our ancestors take the evolutionary path to humanity?"

I think the answer to this question can be shown by talking about human migrations. There are still Europeans even though some sailed across the Atlantic to the Americas. Circumstances aren't the same for all members of a population, so not all head in the same direction. Not that Europeans are more primitive, of course...

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4. Comment #396757 by hinterstella on July 15, 2009 at 12:47 pm

I agree we should let go of the antiquated evolution "icon." I for one would like to see more "Tree of Life" examples. I have to say the "Why are there still chimps?" question is by far the most common misconception. Great job on the recent videos!

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5. Comment #396758 by ods15 on July 15, 2009 at 12:50 pm

@vega

I saw a t shirt with that picture, with the last guy turning around, yelling,

STOP FOLLOWING ME!!

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6. Comment #396759 by blitz442 on July 15, 2009 at 12:50 pm

3. Comment #396753 by Steve Zara

I often thought that the splintering of the English language is a good analogy for this. The American, Canadien, Australian, and New Zealand dialects all "evolved" from British English, yet we still have British English.

Also useful for explaining different rates of change in populations, and to clearly explain how dumb statements like "show me a half crocodile half duck" really are (it would be like asking for a half American half New Zealand dialect).

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7. Comment #396760 by robotaholic on July 15, 2009 at 12:52 pm

Yes, and this was excellent and very needed and it was produced with such clarity- Thanks so much!

But-

Why do humans look so different than the rest of the African Apes? Is it just that my pattern recognition virtual machines in my brain are biased to discriminate my own species better- or can you see as it appears to me- that humans are fundamentally different than the rest?

Why are we so different? (if you agree that we are) It surely is weird-

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8. Comment #396761 by Steve Zara on July 15, 2009 at 12:54 pm

Comment #396759 by blitz442

Yes. Language evolution is a very good analogy, I think.

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9. Comment #396762 by phatbat on July 15, 2009 at 1:04 pm

3. Comment #396753 by Steve Zara

Good point Steve.

I am also thinking that maybe this could be a good example as to why beings like us are not inevitable. It could so easily have just been apes like chimps all the way through.

Up till now anyway. The future is a different matter.

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10. Comment #396763 by mordacious1 on July 15, 2009 at 1:05 pm

Another great video.

I like that the museums that have replicated this display are in Kansas, Texas, Oklahoma, Michigan and Minnesota...along with Nebraska. Strategic positioning I must say. Time to get one up in Alaska (or do they not have museums there).

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11. Comment #396764 by hybridization on July 15, 2009 at 1:05 pm

robotaholic: Have you ever seen a baby chimp or bonobo? The similarity to a baby human is striking; the shape of the skull is most noticeable. If you compare them side by side, baby apes (of any species) actually look more like each other than their adult counterparts.

Additionally, I've found that the more you look at them, the more you learn about them, the more skeletons you see, the fewer differences you see. Check out this photo: http://www.dlwaldron.com/bonobot.jpg.

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12. Comment #396766 by hybridization on July 15, 2009 at 1:06 pm

Ooops, link doesn't work. Here's the original page, with many more photos: http://www.dlwaldron.com/bonobos.html

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13. Comment #396767 by PoliticallyConcerned on July 15, 2009 at 1:08 pm

I am very much enjoying these RDF TV segments - very entertaining and great for understanding and helping others to understand.

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14. Comment #396768 by blitz442 on July 15, 2009 at 1:09 pm

8. Comment #396761 by Steve Zara

Do you know of any other short, sharp explanations or analogies to clear up misunderstandings on evolution. Also what do you think are the greatest misunderstandings.
For me, it was the role of chance, common ancestry, and why some (maybe most) species seem to change very little over time.

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15. Comment #396771 by phasmagigas on July 15, 2009 at 1:18 pm

robotaholic

Why do humans look so different than the rest of the African Apes£ Is it just that my pattern recognition virtual machines in my brain are biased to discriminate my own species better- or can you see as it appears to me- that humans are fundamentally different than the rest£

ive often thought along similar lines.

im sure we are bias towards our own species as being unique, our facial recognition ability is seeminly less accomplished outside of ones own race (however that works) and so it must be especially weak at seeing the differences between other similar species. To our eyes chimps and gorillas may seem more alike than a chimp to a human but pehaps that is not the case at all if one were to compare measurements.

I suspect however that humans have evolved further from the ancestral state than chimps/gorillas have, our bipedalism, rather skinny frame which seems rather weakly muscled (if untrained)compared to chimps/gorillas our strange looking face and big head, our baldness, we could possibly be hideous to a chimp.

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16. Comment #396772 by Steve Zara on July 15, 2009 at 1:20 pm

Comment #396768 by blitz442

One thing does come to mind.

The "crocoduck" objection to evolution is like denying that there was a past migration across the Atlantic because there aren't people now sitting on an island somewhere South of Greenland called Atlantis.

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17. Comment #396776 by phasmagigas on July 15, 2009 at 1:28 pm

steve

The "crocoduck" objection to evolution is like denying that there was a past migration across the Atlantic because there aren't people now sitting on an island somewhere South of Greenland called Atlantis

what amazes me is the fact that some people will hear about the crocoduck (or lack of)and be uttely unable to see their preposterous position, its like creationists ALLOW themselves to be stupid in public to further their religious ideas.

Evolution seems to make the religious layperson feel they are an expert in biology, when in reality they are demonstrating exactly what they dont know but fail to see the weakness of their position.

strange.

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18. Comment #396777 by BeyondBelief on July 15, 2009 at 1:29 pm

RE: 14: The most common misunderstandings?

1. Evolution is a process that happens to an individual line of inheritance... when in fact, evolutionary pressures affect populations.

Take height as an example. In the human population there a range of heights. The entire population is trending taller. However, if there were some pressure applied that made it advantageous to be short, tall individuals wouldn't start birthing "evolved" short kids. The tall folk would die off, moving the bell-curve toward shortness as those who can survive in the new environment reproduce and survive more.

2. Evolution has intent... or rather, that individuals recognize an evolutionary pressure and start intentionally evolving traits to deal with it. This is mostly a problem of semantics in the popular media. The example that sticks in my mind was the discussion on this site about fish that survived in cloudy, muddy ponds suddenly having to deal with clear water. The author wrote in a way that sounded like the fish got together and took a vote on how they were going to survive in the new conditions, and then just went out and evolved themselves some new traits.

3. Evolution is "predictive" or directed toward a goal.

4. That evolution "ends." Seen recently in all the questions about whether or not humans have stopped evolving. This falls in with "Has science discovered everything there is to know?"

Both questions betray a lack of understanding of science and evolution.

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19. Comment #396778 by cmgrote on July 15, 2009 at 1:31 pm

I liked the clarity of the message in the clip as well, and I do understand that we're targeting a very short and straightforward explanation.

However, in the interest of constructive criticism, this could look very similar to pointing at a book and using that as the explanation (e.g. pointing at a picture and using that as the explanation). The clip doesn't really give a scientific explanation for the common ancestry -- just a picture of a hierarchy and assertions about the past (no?)

Personally I'd be excited if there were some links to "more information" / "deeper explanation" so that once the short clip gets people's attention, they can then watch a longer clip which gives a more in-depth explanation of the underlying reasoning for the common ancestry. For instance, I find myself asking "Interesting: how do we know there was a common ancestor so many years ago?" But I don't know where to go from here to easily find an answer... (And this linking to successive detail could naturally carry on several levels, likely ultimately ending up at some references to books / scientific journals, depending on just how deep people want to go...)

I'll be the first to admit: I don't fully understand the science involved in determining common ancestry. I can guess: skeletal commonalities, genetic similarities, etc, but I wouldn't have the information to back it up and make a seamless logical deduction. Would be great if I could trace to that kind of reference material, though, straight from these clips =)

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20. Comment #396779 by HarlanEllisonFan on July 15, 2009 at 1:34 pm

I think these creationists actually think that individual chimps TURNED INTO humans within their own lifetimes!

I love these clips, but wouldn't mind if they were just a bit longer...

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21. Comment #396782 by blitz442 on July 15, 2009 at 1:37 pm

16. Comment #396772 by Steve Zara

Not bad

The development of the automobile might be a useful one for many reasons. Appx 100 years ago we had an unoccupied niche (fast and mobile mechanical vehicles that were not trains), which, after some key, stepwise modifications to an existing carriage, elicited some rapid change and diversification. Although cars of today are far superior to those of the 1930s, many of the key features still remain (internal combustion engine, four wheels usually, rubber tires, etc). Also, the sophisticated level of today's cars makes for very high barriers to entry (useful for explaining why you don't see fish evolving into amphibians today, it would be like a Model-T trying to compete with a Honda Accord).

The analogy is not super-tight but I think useful nonetheless.

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22. Comment #396784 by phasmagigas on July 15, 2009 at 1:42 pm

cmgrote

I'll be the first to admit: I don't fully understand the science involved in determining common ancestry. I can guess: skeletal commonalities, genetic similarities, etc, but I wouldn't have the information to back it up and make a seamless logical deduction. Would be great if I could trace to that kind of reference material, though, straight from these clips =)

thats a fair point you make.

what most people have to assume is that the corroboration of evidence and its expert evaluation have to be trusted at somepoint to be reasonable. creatonists work on the assumption that the experts are liars/evil atheists, whatever. the paper trail you mention is of course available in books, then research publications etc.

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23. Comment #396785 by phasmagigas on July 15, 2009 at 1:46 pm

blitz442

(useful for explaining why you don't see fish evolving into amphibians today, it would be like a Model-T trying to compete with a Honda Accord).

there are still living forms that are potentially teetering on the edge of a new mode of life who currently are succcessful in their 'transitional' existence, eg mudskipper fish, aquatic spiders who still need a diving bell, gliding mammals, seals etc.

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24. Comment #396787 by blitz442 on July 15, 2009 at 1:50 pm

18. Comment #396777 by BeyondBelief

Yes, very good points on how evolution is not goal-directed.

Apparently Collins and even Ken Miller labor under this misconception - it seems they have to in order to reconcile their faith with evolution. I guess this is the real crossroads point; when Dawkins, Coyne, etc saw this for the first time that really pushed them into atheism, while Miller, Collins apparently rationalized it away.

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25. Comment #396789 by Squigit on July 15, 2009 at 1:52 pm

I rather like this one: it's quick and to the point. Sure, we could go into all the genetics of common ancestry (ok, I can't) but I think that would just confuse the audience that needs to be targeted. The evolution of humans is a bit more "in your face" as far as appearances go...it's very, very easy to see the physical similarites between chimps and humans, etc...it's not easy to convince someone of evolution using extinct species--like the one using the whale-- because a number of creationists don't accept fossil evidence to begin with (or even that fossils exist--it's a conspiracy, remember?). With using living species as examples, people can easily see those similarities and they just *have* to wonder why those similarities even exist.

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26. Comment #396790 by Squigit on July 15, 2009 at 1:54 pm

21. Comment #396782 by blitz442

I find that the car evolution analogy doesn't work because: "see! people made the cars evolve so god made us evolve!"

No kidding, heard it before.

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27. Comment #396791 by blitz442 on July 15, 2009 at 2:01 pm

23. Comment #396785 by phasmagigas

Yes... poised to take over those modes if they where to become unoccupied again.

One thing I would like to throw out there. How would you quickly dispose of this query:

"I could see a fly evolving into another type of fly, but I could never see a fly evolving into a man, or even another insect like a preying mantis. You say that there were enough mutations and increases in genetic information to get us from a single-celled organism to everything thing alive today, but maintain that there is no way for a modern fly to ever evolve into a reptile. How can these two things be true at the same time."

My first objection would be to the concept of "types", but how would you deal with the limits on variation that seem to be "built in" to modern forms£


Edit: changed spider to preying mantis

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28. Comment #396792 by blitz442 on July 15, 2009 at 2:05 pm

26. Comment #396790 by Squigit

Did you slap that person£

I guess I would simply ask why God did not skip the Model T and go straight to the Ferrari.

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29. Comment #396794 by ShannonMarie on July 15, 2009 at 2:16 pm

The inane question that Richard addresses so patiently is just another example of human solipsism. Why should chimps or other African apes evolve into humans when there is no particular selection pressure requiring them to do any such thing? As Michel Foucault points out,

"From the moment philosophy became anthropology, and man sought to recognize himself in a natural plenitude, the animal lost its power of negativity, in order to become, between the determinism of nature and the reason of man, the positive form of an evolution."

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30. Comment #396796 by The-bleeding-obvious on July 15, 2009 at 2:18 pm

RD is quite right cos ive just watched star trek, the one were the crew evolve rather rapidly in reverse!

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31. Comment #396798 by phasmagigas on July 15, 2009 at 2:20 pm

blitz442

One thing I would like to throw out there. How would you quickly dispose of this query:

"I could see a fly evolving into another type of fly, but I could never see a fly evolving into a man, or even another insect like a spider. You say that there were enough mutations and increases in genetic information to get us from a single-celled organism to everything thing alive today, but maintain that there is no way for a modern fly to ever evolve into a reptile. How can these two things be true at the same time."

My first objection would be to the concept of "types", but how would you deal with the limits on variation that seem to be "built in" to modern forms£

firstly that query smells of 'ive read this on a creationist website so it must be valid right£'

The whole thing is mainly an argument from personal incredulity "i cant imagine there for nobody can"

the problem with this query is that teh person accept a fly evolving into another fly but cannot see it evolving into a man, well fistly evo theory doesnt specifically say that humans evolved from flies or vice versa, sure things have evolved into orgs vastly different from their ancestors but this person is asking for something that almost DOESNT happen in evolution, they are asking for one very ancient specific basic body plan, in this case an insect to evolve into a man, thats just not going to happen, the common ancestors to flies and man was probably something little more than a tiny flatworm like animal that then split into several main branches. likewise an insect would never evolve into a spider, their body plans are very different.(ah, i saw your edit, spider goes!!)

a single celled organism or very simple metazoan by comparision has the potential to evolve in many ways as the restrictive body plans havent (yet) been imposed (evolved), so that can potentially form very different future body plans as different as worm, scoropions, sea urchins and monkeys. Thats what happened here in the past, your idea of 'built in' was correct, the genes are already there in hindsite and cant be readily undone to form whatever one can imagine.

even the example of fly to mantis is redundant, teh common ancestor to flies and mantids was probably some rather bland thing that looked a bit like a crawling beetle larvae, that would have evolved seperately into the unique body plans possessed by the flies and by he mantids along with their relatives (mantids are allied to cockroaches for eg) once thos especialised body plans are establisjhed they can only add or subtrace incrementally as evolution suggests.

food for thought, the mantis flies, related to lacewings (not true flies)show great convergent evolution and have a very mantis like appearence, of course deep down it is more like a lacewing than a mantis but very cool anyway. the irony is that many mantis flies seem to mimic wasps!

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32. Comment #396801 by mordacious1 on July 15, 2009 at 2:27 pm

27. Comment #396791 by blitz442

It is "praying mantis", as much as we atheists might want to change the name.:)

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33. Comment #396805 by blitz442 on July 15, 2009 at 2:32 pm

31. Comment #396798 by phasmagigas on July 15, 2009 at 2:20 pm

firstly that query smells of 'ive read this on a creationist website so it must be valid right£'

I made it up, it reflects a common question (although I could have easily lifted something similar from a creationist website - that wasn't the point).

I don't think that bringing up the argument from personal incredulity is all that useful in these situations, as it can easily be turned against you (why can't you imagine a creative God).

Your last paragraph I think is honing in on something, but I think we need to better explain how locking into a body plan limits many further variations. Does it limit the usefulness of those variations if they arise, or their production in the first place. Are there genes that put the breaks on variation£

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34. Comment #396807 by clodhopper on July 15, 2009 at 2:34 pm

These RDtv pieces are great.

Could you please make one that explains why we still have chumps though, I can't figure it out.

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35. Comment #396809 by blitz442 on July 15, 2009 at 2:39 pm

32. Comment #396801 by mordacious1

Damn, I should have just written "beetle".

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36. Comment #396811 by Big City on July 15, 2009 at 2:39 pm

robotaholic

...Why do humans look so different than the rest of the African Apes? ... can you see as it appears to me- that humans are fundamentally different than the rest?...

phasmagigas

...I suspect however that humans have evolved further from the ancestral state than chimps/gorillas have...

If, by 'ancestral state' you mean Africa, I would say you're spot on. Body types vary around the globe, and are correlated to different locations and ethnic groups. It only stands out because they chose a Caucasian to represent humans. Had they chosen a photo of a tribal African, it would not have been so conspicuous, but then placing it under the heading 'African Ape' would have caused its own problems.

Also, I love these videos. Thanks, guys.

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37. Comment #396816 by phasmagigas on July 15, 2009 at 2:50 pm

blitz.

I made it up, it reflects a common question (although I could have easily lifted something similar from a creationist website - that wasn't the point).

i assumed it was from a creationst friend, you are right the actual origin of the question is moot but it is the type of thing a creationst might ask, esp as the question shows clearly that the asker (not you of course!) doesnt stand evolution, which is what most creationist questions actually demonstrate.

I don't think that bringing up the argument from personal incredulity is all that useful in these situations, as it can easily be turned against you (why can't you imagine a creative God).

i'd still use that persoanlly, i would suggest to a creationist that i could quite easily imagine a creative god (i have several hindu god statues on my shelves, not all creative perhaps!)the evidence simply shows that it worked by evolution if true, if creation was instantaneous then there is yet any evidence of that, evolution does not disprove a god/s of course. if the question was sincere however i wouldnt need to use it.

Your last paragraph I think is honing in on something, but I think we need to better explain how locking into a body plan limits many further variations. Does it limit the usefulness of those variations if they arise, or their production in the first place. Are there genes that put the breaks on variation£

this is really the meat of my points, once a body plan is established it is simply more difficult to change it totally although many parasitic species do simplyy themselves to a remarkable level but one assumes that the genes for their more complex ancestors are still there, it would be like trying to alter a line drawing using more lines, you can really only go so far (and heck, did i not try to alter the inked phallus/testis drawn on the back of one of my schoolbooks into something less, well, phallic, a bus perhaps! once can add wheels and windows. you see my point,the single cell or simple metazoan is like a blank sheet ready to be drawn upon. the body plans lock as such by simple fact that they are formed by many, many interacting genes and altering just a few genes wont significanly alter the basic structure. eg insects always have six legs despite their extreme diversity.

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38. Comment #396817 by Steve Zara on July 15, 2009 at 2:51 pm

Comment #396805 by blitz442

Your last paragraph I think is honing in on something, but I think we need to better explain how locking into a body plan limits many further variations. Does it limit the usefulness of those variations if they arise, or their production in the first place.

I think you are looking at this the wrong way. There is no 'locking into a body plan'. There is no special limit on further variations.

The only thing we need to realise is that each organism is part of a very complex and inter-dependent system, both within the organism and externally. Almost always, there is only the possibility for subtle changes to be successful. Very rarely, "macro" mutations, such as polyploidy-the duplication of the genome- will be beneficial, but these are exceptions.

So, in each generation, there can only be subtle changes in genotype. To change a 'body plan' in such a way that the resulting organism can survive would take major and co-ordinated changes in genes. And genes don't co-ordinate their mutations!

The idea of body plans is unhelpful. The idea of specific constraints is unhelpful. There is only the principle that evolution can almost always happen through very subtle explorations (please excuse the language of intention) of what is possible.

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39. Comment #396818 by Akaei on July 15, 2009 at 2:54 pm

(I am speculating here. Citations to complementary/detracting facts or studies would be welcome.)

It is within the realm of possibility that a that an evolutionary ancestor could remain as well as evolved descendant species. The evolutionary ancestors to the iguanas of the Galapogos probably exist largely unchanged from time of divergence.

In the case of humans the amount of time and evolutionary pressures would make that possibility extremely unlikely.

We could redraw the tree Richard is showing to to show one straight line from the common ancestor of the great apes to any one of the current descendant species (pick one) with branches going off the "main line" to the other species. I like that the tree design doesn't suggest one evolutionary course is more important than another.

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40. Comment #396820 by phasmagigas on July 15, 2009 at 2:56 pm

big city

If, by 'ancestral state' you mean Africa, I would say you're spot on. Body types vary around the globe, and are correlated to different locations and ethnic groups. It only stands out because they chose a Caucasian to represent humans. Had they chosen a photo of a tribal African, it would not have been so conspicuous, but then placing it under the heading 'African Ape' would have caused its own problems.

yp, my definition of ancestral state would be that which the common ancestor of chimps, humand and gorillas had, i suspect it was (to our eyes) rather small chimp/gorilla like and not human like, humans body shape has arguably changed in more radical ways since then than the other 2 extant lines.

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41. Comment #396822 by Bernard Hurley on July 15, 2009 at 2:59 pm

One thing I would like to throw out there. How would you quickly dispose of this query:

"I could see a fly evolving into another type of fly, but I could never see a fly evolving into a man, or even another insect like a spider. You say that there were enough mutations and increases in genetic information to get us from a single-celled organism to everything thing alive today, but maintain that there is no way for a modern fly to ever evolve into a reptile. How can these two things be true at the same time."

My first objection would be to the concept of "types", but how would you deal with the limits on variation that seem to be "built in" to modern forms

There are no "built in" limits to variation. It is true that a fly cannot evolve into a reptile, but this is because of the way zoologists define reptiles - anything that evolved from a fly would be in the "wrong part" of the tree of life to be classified as a reptile. However given the right environment and enough time a fly might evolve into something that, to the naive observer, was indistinguishable from a reptile in the same way that to, a naive observer, a whale is indistinguishable from a fish.

Suppose that after a neuclear holocaust the only living things on earth were bacteria, plants and cockroaches. There would be a lot of "niches" to be filled and it is quite conceivable that, given enough time, the cockroaches would evolve to fill in those niches. It is quite conceivable that reptile-like creatures would evolve, but, of course, they would not actually be reptiles.

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42. Comment #396824 by phasmagigas on July 15, 2009 at 3:02 pm

steve

There is no 'locking into a body plan'

a body plan of course isnt locked as you say but once its there I suspect that selection pressure works on changing it in (usually) subtle ways and any genetic changes that drastically altered the plan would be detrimental, i suppose the body plan stays put for a while by necessity.

eg an insects leg length may be increased somewhat by mutation, but mutations that have the insect develop an extra thorax segmnent with legs and a thrid wing pair would likely be selected against. potentially of course it could lead to a lineage with 4 pair legs and 3 pairs of wings!

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43. Comment #396825 by Steve Zara on July 15, 2009 at 3:02 pm

Comment #396822 by Bernard Hurley

Suppose that after a neuclear holocaust

I really enjoyed this series:
http://www.thefutureiswild.com/
It speculating about how life may evolve assuming humans left the planet, after having pretty much wrecked the place.

I love the idea of desert snails, fish replacing birds, and potential squid civilizations...

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44. Comment #396826 by phasmagigas on July 15, 2009 at 3:04 pm

bernard hurley

There are no "built in" limits to variation. It is true that a fly cannot evolve into a reptile, but this is because of the way zoologists define reptiles - anything that evolved from a fly would be in the "wrong part" of the tree of life to be classified as a reptile. However given the right environment and enough time a fly might evolve into something that, to the naive observer, was indistinguishable from a reptile in the same way that to, a naive observer, a whale is indistinguishable from a fish.

this 'cladistic' basis of the query is something i didnt mention, i think blitz actually hooked onto this idea when he mentioned 'types'.

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45. Comment #396827 by brunette on July 15, 2009 at 3:05 pm

It'a remarcable that we humans are closer to chimps thant chimps are to gorilas.

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46. Comment #396828 by blitz442 on July 15, 2009 at 3:07 pm

37. Comment #396816 by phasmagigas on July 15, 2009 at 2:50 pm

you see my point,the single cell or simple metazoan is like a blank sheet ready to be drawn upon. the body plans lock as such by simple fact that they are formed by many, many interacting genes and altering just a few genes wont significanly alter the basic structure. eg insects always have six legs despite their extreme diversity.

I see that, this addresses whether the variation would be useful (as you say it would be hard to divert an insect body plan to a reptilian one as it would take many, many variations that would probably not be useful in intermediate stages).

Presumably we have single-celled organisms living now that have variations that may lead to multicelled organisms, but they cannot because the intermediate stages would not be useful (although for a different reason, due to competition from well-established multicelled organisms)

However, can you go one step further and say that such variation does not even arise now in the case of our insect example, even if it did way, way back in some distant common ancestor£

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47. Comment #396829 by Steve Zara on July 15, 2009 at 3:12 pm

Comment #396822 by Bernard Hurley

However given the right environment and enough time a fly might evolve into something that, to the naive observer, was indistinguishable from a reptile in the same way that to, a naive observer, a whale is indistinguishable from a fish.

A very useful point. It has been suggested by some theist biologists (such as Simon Conway Morris) that some patterns in evolution are inevitable. It could be that God designed things so that some kind of 'human' turned up, even if was, say, reptile rather than mammal.

PZ Myers posted an excellent rebuttal to this. Let's look at things that swim fast in the sea. Isn't it amazing that sea mammals such as dolphins and sea fish such as sharks look so much alike? Surely evolution inevitably drives things towards the fish shape? But then, there is the squid...

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48. Comment #396830 by lvpl78 on July 15, 2009 at 3:13 pm

It always makes me laugh when Hitchens refers to himself as a poorly evolved mammal.

For me, I think once people have a real grasp of the time periods involved, everything else falls into place more easily. The analogy of continents drifting apart at the rate finger nails grow is a favourite of mine. Another is if the length of your arm represented a time line of the age of the earth, one swipe of a nail file on the middle finger would wipe out the age of mankind. I love all that stuff, and it's really helpful.

Good video Josh!

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49. Comment #396832 by blitz442 on July 15, 2009 at 3:19 pm

44. Comment #396826 by phasmagigas

this 'cladistic' basis of the query is something i didnt mention, i think blitz actually hooked onto this idea when he mentioned 'types'.

Right, there are no "types", only populations of unique individuals.


Bernard

Suppose that after a neuclear holocaust the only living things on earth were bacteria, plants and cockroaches. There would be a lot of "niches" to be filled and it is quite conceivable that, given enough time, the cockroaches would evolve to fill in those niches. It is quite conceivable that reptile-like creatures would evolve, but, of course, they would not actually be reptiles.

I'm not sure I agree. To get anything near "reptile-like", insects would have to undergo massive changes. Losing that exoskeleton would be crucial to obtaining any type of size - this would be a lot of reenginering. We would need to plausibly show how the intermediate stages from exoskeleton to no exoskeleton would be viable. And again, we are assuming that some insects are even currently cranking out enough variation to get this started.

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50. Comment #396833 by AdamMil on July 15, 2009 at 3:21 pm

And even if we were descended from chimpanzees, that wouldn't require chimpanzees to go extinct.

It'd be nice if he explained the general concept.

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