New Species

[adherent]

How different does an organism have to be to be classified as a new organism? Like, on the evolutionary charts, they only name the "major" organisms, but leave the ones along the way unnamed. Like for instance, on this chart I am looking at right now in my biology book, on the bottom fo the tree is the Remote Common Ancestor (early vertebrate). A "branch" is drawn up to the right Recent Common Ancestor (armidillo-like mammal). It branches there once again now into 2 branches. One leads to the Glyptodont. The other one to the Armidillo. Now in this section of the chart alone, only 4 organisms are named, but shouldn't there be millions of forms named instead. Or are the ones along the branches ignored because they are half-half or is it REALLY because evolution is wrong?

[Corvus]

Or are the ones along the branches ignored because they are half-half or is it REALLY because evolution is wrong?

Half-half? Hah. Okay, the problem has to do with categorisation. Think about history. We organise history into periods where certain features are dominant. The bronze age turned into the iron age, but that doesn't mean there were various bronze alloys that attempted to match the strength of steel. But we don't mention them simply because it isn't important.

This is a poor example, but what I am trying to explain is, there is no such thing as a stage in evolution until a scientist defines it in order to make it easier to study. So, when examining fossils, certain characteristics are taken note of, and then the fossil is placed in an approximate genus. We could give every individual fossil a slight name based on its every minute difference. But why would we?

Another example is if you mapped your entire family tree, stretching back to the "apes", not based on sons and daughters, but based on common features. Would you write each name in the family tree, or would you make it easier by grouping together the people with the same features, even if the features might be more pronounced in some than others?

[adherent]

Um... you still haven't answered how different does an organism have to be to be classified in a new group or new species. How dominant does a feature have to be anyways? Taking humans for example, on average, people used to be taller than they are now (on average); so are we a different species now than in the, say past 300 years?
Oh yeah, I thought all the people in ones family is included in a family tree?

[adherent]

And about the scientist grouping together similar organisms into a group for easier studying: What does it matter if it is easier to study or not? they should do their duty as scientists to group up organisms into the same species based on science which I think is not really clearly defined as they leave all the transitional forms in relative anonymity.

justice for the transitional forms:)

[adherent]

Shild:
You see, two groups of organisms are considered two different species if they cannot/do not mate to produce fertile offspring.

As you can see above, Shild defines two separate species if they cannot mate. But then, how do we classify the different species of humans if we didn't mate them. It is then when scientists classify based on the organisms features. But why should they classify the extinct any different than the living.

[Corvus]

Um... you still haven't answered how different does an organism have to be to be classified in a new group or new species. How dominant does a feature have to be anyways? Taking humans for example, on average, people used to be taller than they are now (on average); so are we a different species now than in the, say past 300 years?

There are over 5 different definitions of what constitutes a species.
I strongly suggest you read this:

http://www.talkorigins.org/faqs/faq-speciation.html

Oh yeah, I thought all the people in ones family is included in a family tree?

I said "If we created a family tree based on characteristics".

[adherent]

5! that is a lot of different definitions of species. Who gets to decide then about classifying new species or does every scientist go on one of the 5 definitions? I recently emailed a professor (he got his Ph.D. at harvard) and he defined a species is something that can not breed fertile offspring with another species, thus we can discern between two species. My other question was how would we know if humans right now could not successfully mate with humans 5000 years ago? And once more: How dominant does a feature have to be?

[Corvus]

5! that is a lot of different definitions of species. Who gets to decide then about classifying new species or does every scientist go on one of the 5 definitions? I recently emailed a professor (he got his Ph.D. at harvard) and he defined a species is something that can not breed fertile offspring with another species, thus we can discern between two species. My other question was how would we know if humans right now could not successfully mate with humans 5000 years ago? And once more: How dominant does a feature have to be?

Did you ask him how we define species that are no longer living? Also, was his Ph.D in biology, or a field similarly related to evolution?

That particular definition of a species is called the biological species theory, and applies to species still living. There are considerable complications and complaints on this theory, since when you get to creatures that are asexual, confusion arises.

It's generally not accepted as the best way to classify species.

The folk concept is far simpler. You can tell a species apart just by looking at them.

Scientists don't just pick a species definition. Different species definitions suit different purposes. One is more often used for plants, another for animals, another for protozoa, and another for asexual critters. When the species are living, we can class them by behaviour and by compatability. But when the species are fossils, we are forced to use other definitions. Yes, there is expected to be some fuzziness between species. This doesn't constitute "bad science", since the end result is the same, and reveals common descent and slight change over time.

This is also a problem for creationism. When its difficult to decide which species a particular fossil fits into, the ancestor or the descendent, this presents a question to Creationism, which, at the most accepting, only allows micro-evolution.

How this topic has anything to do with the validity of evolution is beyond me. The theory would stil be perfectly tenable if every creature were called a boink. The fact is, we can identify changes over time in related fossils, regardless of what we call them.

[adherent]

the professor was a specialist in evolution, biology, dinosaurs, and everything to do with fossils.
Folk concept is horribly too simple. going by looks is not very good as organisms of the same species can look totally different.
If it doesn't matter what we call them then we might as well say that all organisms on the human evolution tree are in fact just all humans.
Wait, that is pretty bad science if the definition of species applies differently to different organisms. One of the few exceptions should be asexual organisms.

Ill post what the professor dude says when he replies again to me.

[Corvus]

the professor was a specialist in evolution, biology, dinosaurs, and everything to do with fossils.
Folk concept is horribly too simple. going by looks is not very good as organisms of the same species can look totally different.

Do you often confuse apes with humans, adherent? No matter how differently we look, we all have similar characteristics. Bone structures, brow ridges, size, are mostly similar. Mostly being the operative word.

Wait, that is pretty bad science if the definition of species applies differently to different organisms. One of the few exceptions should be asexual organisms.

Why is it bad science? The purpose of science is not to think up names of everything. If we didn't have a language, and only spoke in grunts, the science would be the same. Animals change over time. This is observable without language. Where we set the stages and what we call the stages is irrelevant.

Ill post what the professor dude says when he replies again to me.[/quote]