I believe in evolution and my boyfriend does not, he pointed out that there is a gap somewhere before the dinosaurs. Basically traditionally it is believed all life began as very small organisms that evolved into plants and living creatures, then there were dinosaurs, then they died and then there were animals which theory leads us to believe in the whole common ancestor between monkeys and humans that has now gone extinct (no humans did not evolve from monkeys, that’s not what the theory says). Now anyway my question is, in this timeline… there is super small organisms first then all of a sudden there are huge incredibly large dinosaurs but no evidence of creatures at an inbetween size?? how to you go from super small to super large? it doesn’t make sense to me but i’d sure like to have an answer.
Hi fireangel. Where are you (or your boyfriend) getting the idea that there weren’t any small-sized precursors to the dinosaurs? Sure there were. AFAIK, dinosaurs evolved from much smaller reptiles: they didn’t just pop into being with no plausible line of descent. Yes, they grew and radiated rather rapidly (rapidly on evolutionary time scales, at least), but there was no sudden jump “from super small to super large”.
There’s one heck of a lot of life forms between single celled life and dinosaurs. There’s a whole slew of ocean-based life moving through type of arthropods and fish and leading to small land-based life forms and theraspids and such.
Oh, thank god. When I saw ‘guest’ and I saw the thread title, I thought it was going to be another drive by “Evolution is just yur opinion, dood, and is totally illogical” thread. On top of the rapid degeneration of this thread, it would have been too much for my weak constitution to withstand.
Is that a small enough dinosaur ancestor for you?
Size is a fairly trivial attribute. You would do better arguing based on “complexity” or some other fuzzy concept. That way, if anyone shows you smaller critters that lived earlier than the big ones, your “size-ism” can be damaged, but if you argue based on “complexity” you can always redefine what you mean by it…
Did anybody else end up reading that to the tune of “The Twelve Days of Christmas”?
And a par-tri-idge in a pear treeeeee! (Actually, it appears that both partridges and pear trees belong farther back in the list, dunnit? About 150 Mya.)
I think where your boyfriend is getting confused is because of the scales of time we are talking about here. I saw a show on Discovery about time a few weeks ago that really puts things into perspective. If you measure time as a rough distance, then picture this: If the entire time from the earths formation until today is the distance from San Francisco to New York city, then all of recorded time would only be about the size of a small table located right at the end of New York City. If we got back to the earliest ancestors of man you are probably talking about less than the space of a house…with that table of human history at the end of the house. Dinosaurs died out somewhere when you are first entering the state of New York…and complex life really began sometime when you entered Ohio (IIRC from the show).
The scales of time we are talking about here are something that few people can really grasp intellectually. I thought this show (not sure how accurate it is but probably roughly correct) was one of the best demonstrations in terms people could really grasp that I’ve seen.
-XT
p.s. Anything wrong about my little demonstration is probably from me not the show…I’m doing it from memory.
It always strikes me as kind of strange when someone states “I believe in evolution.” For me, it’s like someone saying “I believe in math.”
Your bf is perhaps talking about the Cambrian Explosion?
I liked the example I heard recently; we are closer in time to Triceratops (65 million years ago) than Triceratops are to Diplodocus (150 million years ago).
Good point. One doesn’t ‘believe’ in evolution. One accepts it as best describing the facts.
Don’t get me *started *on math!
It always strikes me as kind of strange when someone claims that something is someone else’s “belief”, then explains it in such a way as though they believe it themselves.
:dubious:
I’ll have to tell my daughter that she must stop pretending that her triceratops and her diplodocus are playing with each other. This appalling anachronism must end!
(looking around the room, glaring)
Welcome, xxfireangel13xx! “Evolution” is not a belief system, like a religion, but I assume you understand that and mean that you believe that evolution is the best way we’ve found to explain why organisms today are different from organisms in the past. But some of our friends here are a bit literal-minded and lacking in people skills. You know–nerds. 
Others are wiseasses. Feel free to mentally knock them upside the head, though if you wish to do it verbally we have a separate forum for that. One that I don’t recommend polite young ladies like you to enter. :eek:
Humans, chimps, monkeys, lemurs, etc. are all primates. Just like mice and rats and beavers are all rodents. If you trace back all the living primates to their common ancestor, you’ll find that ancestor lived before the extinction of the dinosaurs. Same for the common ancestor of all living rodents. There are thousands and thousands of species, some of which are thriving (and often branching out into new forms) and some of which are going extinct. It’s not just some linear process where one thing leads to the next thing then the next thing, etc. There were gigantic fish in the oceans before there were gigantic dinosaurs roaming the earth.
Life started out as single celled organisms maybe 4B years ago (that’s billion). The first land vertebrates didn’t show up until about 500M years ago. Still, they had a long, long time to evolve into gigantic dinosaurs. The first dinosaur appeared about 230M years ago and might have looked something like the Eoraptor. An animal like that can easily evolve into a giant in just a few million years. I say “just a few million years”, but that’s a pretty long time even though it represents only a fraction of the time that land vertebrates have existed. As a reference, our species has only be around for about 200,000 years (.2M years) and you only have to go back about 5-6M years to find the common ancestor of humans and chimps.
The answer is “there were lots of intermediate critters between the super small guys and the huge guys”. Let’s just talk about dinosaurs themselves for a bit.
Dinosaurs are traditionally broken into two major groups: Ornithischians (the “Bird-hipped” dinosaurs) and Saurischians (“lizard-hipped” dinosaurs).
Within Ornithischia, there are 3 major groups: the Thyreophorans (which include big guys like Stegosaurus and Ankylosaurus; the Ornithopods, which contains the Hadrosaurs (“duck-blled” dinosaurs); and the Marginocephalians, which include the horned ceratopsians (like Triceratops) and the “bone-headed” Pachycephalosaurs (like Pachycephalosaurus)
Now, each of those groups produced some pretty big critters. But early, on, those groups consisted of much smaller critters. One of the earliest Thyreophorans, for example, was Scutellosaurus, which was only about 4 feet long. Yet its descendants would be critters like Stegosaurus - which grew to around 30 feet long and 14 feet high (including plates)! One of the earliest Ornithopods was Othnielosaurus, which was only 6-7 feet long and weighed only about 20 pounds or so. Yet its descendants include Parasaurolophus, whose skull alone is 6-7 feet long, and the whole animal weighed almost 3 tons! And, of course, the earliest Marginocephalians began small, too: Psittacosaurus was an early member of the Ceratopsians - it was only about 6.5 feet long and weighed a bit over 40 lbs - which would later yield monsters such as Triceratops, which weighed in at over 10 tons, and whose skull alone was larger than Psittacosaurus!
On the other side of the dinosaur tree, we have the Saurischians, which would eventually give rise to some of the most well known dinosaurs, including the large Brachiosaurus and Tyrannosaurus.
Within the Saurischians, then, we have two major groups: the Sauropods and the Theropods. The sauropods were all the long-necked giants like “Brontosaurus” (more correctly known as Apatosaurus), while the Theropods were all the two-legged “meat eaters”. Theropods also gave rise to birds, indicating that they weren’t all giants!
Early sauropods were pretty big, but nowhere close to the size they would eventually achieve. Thecodontosaurus is an example of an early ancestor of the giant sauropods, measuring a mere 4 feet long and about 25 pounds, while the much-later Paralatitan weighs in at a massive 80 tons and is over 100 feet long!
As you might guess by now, Theropods also had humble beginnings: Eoraptor, which John Mace mentioned above, is one of the earliest dinosaurs and the oldest known theropod. And one of the smallest that wasn’t a bird! One of the largest of the theropod dinsoaurs was Tyrannosaurus, which was also one of the last of the dinosaurs before they died out.
There are, of course, many intermediate dinosaurs between the small “first” guys and the much larger ones that came after. But the gist is that dinosaurs started small, and only got larger over time. By the time they died out, the largest ones were the largest animals ever to walk the Earth!
This is, incidently, the story with most major groups: they almost always start out small and grow to large sizes later in their evolution.
Kind of a tangent, but maybe not. What does your boyfriend believe? - the answer to this will make a big difference as to how the topic can (if at all) be meaningfully discussed with him.
I’ve only met one person who flat out didn’t accept evolution, but wasn’t a creationist of any particularly identifiable kind - my previous (now retired) boss - he argued the origin and diversity of life to be an unsolved mystery, and would come out with such gems as “If sharks evolved, why isn’t everything a shark?” (I tried to explain about different niches, but it didn’t go in) and “If evolution is true, how could something as ridiculously unsuited for survival as the giraffe come to exist?” (I pointed out that if the giraffe was unsuited for survival, there simply wouldn’t be any giraffes).
I hear the alternate “If people evolved from primates why do primates still exist?”, which, in one instance, prompted me to diagram an admittedly crude cladogram while attempting to explain branching that resulted in a vacuous stare of incredulity from my acquiantance.
When presented with this argument I’ve said ‘You’re wrong. Man didn’t evolve from apes. Man and apes evolved from the same ancestor.’ Anything after that is just reinforcing the idea that they have it wrong.
Yeah, this is important. I’ve never met a person who both proclaimed that they did not believe in evolution and was actually willing to rationally discuss it. Challenging a belief like this might be a good way to get dumped if your bf is not the listening type.