Hi Peg, thanks.
the bible isnt a scientific book so its doesnt go into great detail and the only distinction that it does make is that some, lets say cats, were 'domestic cat kinds' and others 'wild cat kinds'.
Agreed, however this strikes me as more of an argument for kind = sort = type = group, with no specific meaning other than saying there are different types of animals.
from the first wildcat kinds, come all the variety of wildcat kinds and vice versa.
Is this specific in the bible? Or are we talking interpretation again? Either way we still have clades of animals descendant from parent populations.
how does this idea fit with Darwins theory of the origin of species?
Have you read Origin of Species? It is available on-line at
http://darwin-online.org.uk/content/frameset?itemID=F373&...they have each edition on-line, so you can look at the differences.
Darwin talked about descent of species from common ancestors, and this is what clades document. The theory is that new daughter species are the result of descent with modification from parent species due to natural selection occurring in different ecologies, and resulting in reproductive isolation. Again, this has been observed to occur: new species have been observed to develop in this manner.
...how does this idea fit in with clades?
The idea of clades is that all descendants of a parent species are members of the same clade.
|
|
^ a
/ \
/ \
/ ^ b
c ^ / \
/ \ / \
/ | | ^ d
e ^ | | / \
/ \ | | / ^ f
/ \ | | | / \
This is all one clade -- all lineages at the bottom are descendant from the parent population (a) at the top. It also has two clades that are sub-categories of the main clade, one to the right side and one to the left side: each lineage at the bottom right are descendant from the right branch (b) at the top, and each lineage at the bottom left are descendant from the left branch (c) at the top. You also have sub-clades (d), (e) and (f), and all of these clades form a nested hierarchy of descent from common ancestors.
earlier someone commented that birds are decendents of dinosaurs ...
That is what the evidence shows.
I think creationists have a problem with the evolutionary view that all the clades orginally decended from some other clade.
And evolutionary biologists would have trouble with that view as well. The evolutionary view is that sub-category clades are descendant from a parent population that forms an overall parent clade that includes all the descendants from the parent populations. The process of forming branches by speciation and subsequent sub-category clades by further branching via descent and speciation, in an on-going process.
Darwin said he did not view each species as a special creation but as decendents from just a few species.
Darwin hypothesized that all clades could be related by parent populations. The question is not what the theory says, but what the evidence shows: if the evidence shows nested hierarchies of descent from parent populations, then this conforms to the concept of descent from common ancestors, and the formation of clades, with sub-clades and parent clades.
I see you mention dinosaurs and birds, yet that kind of contradicts your explaination of the clades...this is what i dont understand. Scientists have learned that animals reproduce after their clades, and these clades produce variety (speciation?) and they can only breed with each other etc etc
Clades can be classified from taking a specific parent population and then following the evidence to all the extinct and living descendant branches, but they can also be found by looking up to parent populations to see what previous species the specific population has descended from. See the diagram above again: clades are nested inside clades, with each clade being defined by a specific parent population, where subsequent descendants are members of that clade. Draw a horizontal line through the diagram at any level, and each of the populations at that line only breed with members of their breeding population. We see this today, where the current horizontal line is today.
but its still accepted that a clade will eventually become something completely different, such as a dinosaur to a bird
Again, this is a matter of what the evidence shows, and whether that evidence conforms to the concept of clades or contradicts it. When we talk about the future there is no indication of what will occur, no need for "completely different" change to occur, but also no impediment to contining change. When we talk about the past, the question is what the evidence actually shows. When I was in high school, birds were not considered\thought to be descendant from dinosaurs, but recent fossil evidence shows a clear pattern of descent from specific parent populations that were descended from dinosaurs.
The problem you have is not what the theory of evolution says, rather it is what the evidence says.
Enjoy.