This is not the same logic. There is NO barrier to how soon or late tetrapods can appear.
The whole point of my Dinosaurs vs. Large Mammals scenario is that Dinosaurs PREVENTED the emergence of large mammals. And that’s why the bones of both can never be in the same matrix.
There no food-chain barriers to the emergence of Tetrapods.
DCS, you don’t really seem to have your heart in arriving at scientific comprehension - - you appear to be here for the simple motivation of scoring debating points…
I would not expect it to be true 100% of the time. Sometimes it would be more than 4my, sometimes less. That’s why I used the word “typically” in my post.
I will give one example: horses and donkeys can interbreed to produce mules, but mules are not successful. (They are useful and viable, but that’s not the biological definition of successful.) They diverged from a common ancestor 4mya.
Note that the ability to produce offspring and the ability to produce successful offspring are not the same thing.
I’m trying to follow - If one species branches into four separate species via evolution and over the ten millennia, three of the species die off, isn’t it true the extinction of three species has occurred? When we start talking about marsupials vs. placentals we aren’t talking about species. And when we are talking about an ancient ancestor species and a modern species, we aren’t necessarily talking about the same species, right?
so there is no barrier to how soon or late whale can appear. the same logic. and therfore your claim : “we NEVER find marine dinosaur fossils in the same layers as we find whale fossil” doesnt hold water.
While technically this is true … I think virtually all geneticists would agree that there is AT LEAST a “species” distinction between Marsupials and Placentals. I picked this most dramatic of distinctions to make the discussion simpler… not to attempt to say a marsupial “x” and a placental “x” are just 2 species from the same genus. Placentals and Marsupials are WIDELY separated on the tree of life!
I agree with you completely that the odds of an ancestor creature and a modern look-alike being “the same species” are pretty low! As one person has already said, assuming you could use a time machine to mate a modern animal with one from a few million years ago, the odds are pretty high that there would be no offspring, or that the offspring would be sterile (like mules).
So you accept the standard definition of the species boundary and Dr. Hone’s rough approximation of the average duration of a species.
The point about what constitutes a “kind” doesn’t add any useful information to the discussion of how many species have ever lived.
Thus it looks like Dr. Hone’s math holds up, extant species are less than 1% of the species have ever lived…and we can end this thread and move onto something more important.
maybe its my english. but where did you get this from?
no. he doesnt gave any scientific evidence for this claim. the main problem with this calculation is that he consider a species that dissapear in the record as species that extinct. when in reality it may evolve into another species. or the species population just get to small to leave a fossils.
so he cant prove that 99% of the species get are extinct.
You can’t have a big whale until you have a big mammal. So the SOONEST you can have a whale is when there aren’t any dinosaurs around to eat up any mammal that gets too big to hide well.
So… YOUR comprehension of how extinction affects evolution is clearly in question.
Since the early Tetrapods were most likely the TOP of the food chain (rather than the bottom), the “whale” logic does NOT apply to them.
Carnivore mammals during the age of dinosaurs were small enough to hide. Whether it’s a mouse, shrew or a hypothetical “saber-toothed mouse” … mammals arrived after reptiles had gained global dominance. There was no way for a mammal population to develop into large sized creatures if their size made them more noticeable to the alpha predators of the dinosaur world.
Small mammals entering the ocean are just as likely to get eaten by fish as by small mammals contending on land with dinosaurs.
There is a reason why the common ancestor of all whales was a relatively good sized mammal.
ONE] Hmmm… if there is a shrew-like mammal that eats worms… is that a carnivore or a herbivore?
TWO] Assuming you are reporting this information on the “raccoon size” accurately, it doesn’t really change the discussion. A raccoon is MUCH bigger than the usual mammals during the Age of the Dinosaur. Mammals in that time were mouse-like and shrew-like… and/or lived underground.
When I say “small” … I mean REALLY small. DCS, you should read more science on evolution.
Why did you totally ignore what gbrooks just told you?
@dcscccc, I often wonder if language obstacles are preventing you from understanding what you are being told. Is this why so many of your recent posts don’t seem to follow in a logical way?
I’m not criticizing you. I’m simply acknowledging that much of the talking past one another in this thread may be due to language comprehension issues. I think you are an intelligent person. I also think it is commendable that you are working on your English language skills by means of forum participation. Yet it is becoming evident that you are dealing with more than just the scientific concepts.
Here’s a tip which has greatly helped some of my international students:
For a given scientific concept, first look up the term in the Simple English Wikipedia:
Once you are comfortable with the material there, look up the same term or topic in the regular standard Wikipedia in English:
This can be a tedious process and no doubt frustrating at times. But I’ve had several students tell me that they were surprised how many words they thought they understood but actually didn’t. And this kind of deliberate process may have been the only way for them to systematically identify those comprehension issues.
I admire your tenacity and willingness to debate and a non-native language. And if you invested even just a small percentage of your posting time and energy in the process I just described, I think you would find it both educational and ENCOURAGING. It is the kind of practice in the language which would also help you develop an intuitive grasp of whether to use strong or weak verb tense paradigms, for example. (As a linguist, I can’t help but notice how you mix them. That’s a very common phenomenon for those learning the language—and even native speakers of English sometimes get confused on that. It’s another reminder of the waves of invasion of England which complicated the language.)
Perhaps others here have additional types of practical advice for you. We probably have other non-native speakers here who went through similar hurdles and could provide specific help adapted to your particular native language background.
I thank you for the reference to the Repenomamus ! Yes, I agree that this is an unusually large mammal for the Age of Dinosaurs. Not surprisingly, it appears to be a carnivore, and not subsisting by chewing plants while basking in sunshine in wide open fields.
There are two known representative species, and it looks like they had a limited range and a limited time span of success: from 125 Million to 123.2 Million Years Ago. While they are definitely larger than mice and shrews … they are still very small compared to Elephants, Giraffes and Rhinoceri.
If they had survived longer, maybe they would have been the common ancestors of whales.
DCS, remember what we are disputing. You wanted to know why I say we would never find large mammals living with dinosaurs… because their size would attract the notice of dinosaurs and they would become lunch.
Your finding the Repenomamus doesn’t change this general point. All it does is shift the boundary line a little bit as to what would be the largest limit of a mammal during the Age of Dinosaurs. But I’m not trying to argue what the limit is. I chose the phrase “large mammals” in order to avoid this kind of quibbling.
NOW … if you can find something the size of an ELEPHANT that successfully survived for millions of years during the Age of the Dinosaurs … that would be worth talking about!
“A raccoon is MUCH bigger than the usual mammals during the Age of the Dinosaur. Mammals in that time were mouse-like and shrew-like… and/or lived underground.”-
so its change everything. i prove that there is no problem for evolution if we will find a large mammal (by your own definition of “big”) with dino.
not at all. even if we will find such a mammal evolution can explain it without any problem.
so bottom line- we see that a big mammal (again- by your own definition) could be find with dino without nay problem for evolution. and therefore evolution isnt a scientific theory.
I have repeatedly used much larger mammals as my test cases: Elephants, Giraffe and even “Rhinocerus’s” .
l have conceded that the mammalian predator you found is larger than I thought was likely … but it doesn’t change my original scenario. At no point has my “test case” relied on mammals that were only a meter long.
You are just trying to play “gotcha”, DCS.
As it turns out … that larger predator has the bone structure of a marsupial… PROVING it’s ancient location on the tree of life.
If you find LARGE mammals… do I need to switch to the word GIANT mammals to avoid confusion?.. are placentals (Elephants, Giraffes) … these GIANT placentals could not evolve until dinosaurs are gone.
Your Young Earth Creationism does NOT have an answer for why they don’t appear until AFTER the dinosaurs are gone.