MarkT said:
How do you explain 30 families of frog then? Why aren't they considered species ie. they come out of a single gene pool.
Because there are 3,438
species of frogs. The 30 families group similar species together. Any yes they all came from an original ancestor with one gene pool. But today there are 3,438 different frog gene pools.
I'll bet you can tell they are frogs just by looking at them. So in my opinion, they belong to one family.
Would you call
this a frog?
All frogs do share common characteristics. That is what makes them frogs. But they are larger than one family. There are about 30 families altogether in the order Anura, or Salientia.
What you're saying about humans is not a fact.
Anyone can see humans are not apes. Apes belong to the monkey kind. That is apparent.
Aron-Ra has covered this.
The difference between apes and humans is far greater in my view. What you call non essential or minor are evidence they don't all come from the same gene pool.
Those are evidence they no longer share the same gene pool. But their ancestor did.
How you classify them is an entirely different matter. It's an arbitrary thing. Artificial.
Biological taxonomy is not arbitrary. It used to be. Prior to the work of Linnaeus, every botanist and zoologist devised his own classification system. The point of the Linnaean system was to be truly systematic in classification. And the cladistic system used today aims to classify species according to their relationships.
I can sort books, for example, by the author, title, subject, etc.
But we can't sort animals that way. If you use morphologic characteristics, you get only one possible classification system. You don't get one for teeth, a different one for noses and a different one again for eyes.
All of the characteristics lead to the same classification.
Furthermore, when you add in genetic information, you still get the same classification.
That's rather like finding not only that you get the same classification of books whether you sort by title, author or publisher, but you
still get the same classification if you sort by the font used.
A nested hierarchy is a very special kind of classification. Most things cannot be classified in a nested hierarchy to begin with. And to get the same nested hierarchy from a totally different system of classification (genes instead of morphology) is quite astounding.
See. You can call them families because frogs speciate at a faster rate but the definition of family has now changed.
It's now a step in the hierarchy of the system of classifying things that is being used.
So these examples are "families" because they contain species.
However, my definition of family remains "the gene pool" the animal comes from.
I don't know of any evidence that frogs speciate at a faster rate. Of course families are groups of species. All taxonomic terms above species refer to groups of species. But that also means they originally derived from a "common gene pool" ----the gene pool of their common ancestor.
Well you're using the scientific terms that came out of the system you're using. Again, it's a matter of different rates of speciation which is confusing the picture.
I would suspect mammals are more complicated. Therefore I would not use "kind" to refer to mammals.
Speciation rates tend to vary more with environmental conditions than with type of animal. Mammals speciated very rapidly in the early Cenozoic, but not so rapidly before or after. As for mammals being more complicated than frogs, you are only guessing. You need to actually study the animals before you can make that conclusion. The scientific terms you object to are based on detailed study.
For example, here are a description of one of those frog families: the dendrobatids (Dendrobatidae)
Many dendrobatids are brightly colored (and presumably poisonous to some degree). However, there are many dull-colored species in the genus Colostethus, mostly brownish, that do not appear to be poisonous. Indians of the Emberá Chocó in Colombia rub their blowgun darts onto the backs of Phyllobates terribilis to load the darts with poison (Myers et al., 1978).
The reproductive behaviors are diverse. In all species of dendrobatids for which data are known, the tadpoles are carried on the back of the adult. In some species it is the male; in others it is the female that carries the tadpoles. Generally the tadpoles are transported to a body of water, usually a stream, but also small ponds, the water-filled axils of bromeliads or some other small container, in the case of some Dendrobates. The female will transport one tadpole at a time in this way, and there is only one tadpole per crevice. These tiny hiding places offer little in the way of food resources to the developing larva, and the female has evolved the remarkable behavior of depositing unfertilized eggs in the axil to feed the developing tadpole. The normal beaks and denticles that are found in most tadpoles are reduced or lost in these bromeliad-developers.
Have you ever studied tadpole beaks? Can you tell by looking which frogs are poisonous and which not?
It's also a matter of interpretation.
Classification is a matter of observation. That is why creationists of the 18th and 19th century were able to classify plants and animals based on morphology, yet still come up with the same hierarchy as 21st century taxonomists get basing their classification on DNA sequences (which implies common ancestry).
So it does come down to what we think.
It comes down to what we have studied. Otherwise what we think has no foundation in reality. You can dream up whatever ideas you want, but it's nothing but imagination if it doesn't accord with actual observation.
No. What I meant was, if I wanted to know what science said, I wouldn't be arguing here. I would be reading books and journals etc.
The reason we're here is to discuss this reality, what science says, to see if there is any truth in it.
You are contradicting yourself. You cannot discuss what science says or pass any judgement on whether it is true unless you do read those books and journals. You have to know what science says, and what nature says, in order to judge the truth of scientific statements.
You have to defend your belief.
No you don't. You can believe whatever you please.
But when you say your belief is a true reflection of reality, then you have to defend that statement.
I don't have to have the answers. My argument is not that I have the answers. My argument is that science doesn't have the answers. Science has not proven descent by modification.
You can't argue that science doesn't know the answers when you haven't even checked them out.
No. Not the way I'm using it. A kind would include several, maybe many families. When I use the word, I'm guessing, because I don't have a clear definition of "kind".
Then why use the word at all?
Like I said, there are many ways to sort things. Like how living creatures move, what they eat, whether they walk on all fours or not, whether they have wings etc.
So would bats, birds and insects all be one kind because they all have wings? Or would swallows and ostriches be different kinds because one flies and one doesn't. Would penguins, whales and salmon all be one kind because they all swim?
You have to do some thinking about which characteristics are meaningful for classification purposes and which are not.
So sorting by morpholgy is only one way.
But the things you mentioned above---what they eat, how they move, are not morphological characteristics. Nor is morphology the only possible basis of classification. So is physiology, and so is gene sequencing.
But the way of classifying things should not be informing you. A classification system can not by definition tell us how things are related.
The Linnaean system doesn't because it wasn't designed too. But the cladistic system is based on relationships.
This system you're using isn't balanced. It's not being truthful.
That's an unsupported assumption on your part. You don't know the system, so you can't say it is unbalanced or untruthful until you take time to study it.
As I said, mammals are less likely to speciate, with the exception of birds, I guess, because they can range further, than frogs and insects.
Scroll down to
the geographic distribution of frogs.
As for insects, there are 750,000 species which represents 75% of
all animal species. And there are very few places where you do not find insects.
Therefore you can't see the hierarchy that probably exists as you can with frogs and insects. Mammals have fewer offspring, take longer to breed, have fewer places to hide unless they live in a jungle.
What makes you think that? Mammals are also grouped in orders: Rodents, Ungulates, Carnivores, Bats, Primates, etc. and each of these are divided into families, genera and species just like frogs and insects are. Yes, there are fewer of them, but the same hierarchy applies.
So the family is the original parent population that species come from.
For example, all descendants of
this parent population belong to the same family?