A common argument that I hear put fourth by creationists is that organisms only give after their own kind? But what exactly are these kinds that they refer to? It can't be species because there are many observed instances of speciation, so what other definitions of kinds are there? There are various clades of organisms but each level of taxonomy that exists is pretty much arbitrarily defined. One thinf that I hear creationists say is that we see dogs giving rise to new varieties of dogs but they're all still dogs, we don't see them giving rise to cats. But cats (felidae) and dogs (canidae) are independantly derrived lineages on opposing branches of carnivora, so a dog evolving into a cat would actually violate one of the most basic rules of evolution: The law of monophyly. This law states that every living species of organism is still a modified version of what it evolved from. Every descendant of the common ancestor of the dogs will still remain a dog just like every descendant of the common ancestor of cats will still be a cat and the further you look back in time at any clade of organisms the more they will resemble the common ancestor. Even though dogs and cats are independantly derrived lineages, both belong to the larger collective known as carnivora and the more basal the member of the dog and cat families are, the more they will resemble each other. Here's a wolf
And here's a leopard
They may not look much alike each other, but if we look at the most basal Canid, the grey fox
And a more basal cat like the wildcat
You can see some resemblance albeit not as much as they do either the wolf or leopard. And if we look at the most basal caniform the right tailed "cat" which is actually a raccoon.
And the most basal of the cat branch the genet
You can see that they bare some resemblance to the fox and the cat but have a greater resemblance to each other because they most closely resemble the ancestor of dogs and cats.
Most Helpful Girl
Okay, people that usually say things like that aren't typically very educated so like a giant man in the sky pointing his finger and making things so makes sense to them. No use trying to use reason with such types. They have none.0
Most Helpful Guy
The problem is that creationists don't understand the spans of time needed for evolution to create a new species. While it is true that each species only gives birth to their own species the small changes over millions of years can result in a very different species than what they started with. Even though every ancestor gave birth to a child of their own species. The ancestor of millions of years ago, would no longer be seen as the same species as its current descendant.
There is no clear line we can draw between one species and a member of a different species. This is a gradual change over an an incredible amount of time. This is what creationists that don't fully understand evolution, have such a hard time accepting.1