Question about mammals

[Yoozer_Naym]

I've noticed lately how out of all the classes of the animal kingdom, that mammals appear to be the most diverse in anatomy and physiology. I find this particularly interesting since there are very few mammal species. Even more interesting to me is that mammals not only make up such a small group, but we have only been on this earth such a short time compared to most other animal groups such as insects, amphibians, reptiles, etc. But as many kinds of insects there are, they all seem to have more in common anatomically to one another than the few mammal species do. Take, for example a mouse, a lion, an elephant, a bat, a whale, a giraffe , and a human. Now look at how drastically different all those animals look from each other. Yet if you go back in time to before the dinosaurs went extinct just 65 mya, the common ancestor for humans and elephants (to my knowledge)looked like some rodent. Now you can go back hundreds of millions of years and find that a lot of groups of reptiles such as crocodilians and turtles which are still around today, were pretty much the same. Same goes for fish and arthropod groups(by groups I mean classes,orders,families, genera,etc). So what I would like to know is how have mammals, who are so young and so low in numbers have diversified so much so quickly? Is there something about mammals that are unique, or is there something I'm missing? By the way, if anything I said here is incorrect, please feel free to set me straight. Thanks.

[Kyrisch]

The same diversity exists in the insect world, if not more. Mammalian diversity is not as unique as you perceive it to be.

[jonathangiraldo]

Yoozer_Naym,

 

The evolutionary individual physical characteristics of mammals you perceive to be unique, are really subtle and superficial. All mammal have the same number of organs whose function is extremely identical, the same number of extremities that evolved slightly differently accoring to the species' needs (as in the elongated neck of giraffes which is no different than that of a human, except for the self replication and prolongated extention of the already present vertebrates, as in the segmented body of the trilobite). Other striking features such as size can be nullified based on the fact that evolution claims that change in size can easily be achievable depending on the adaptability of organism in need, as in the case of the endricothere. Genetically a mouse shares 90% of its genes with humans. While mammals have pretty much the same organs and fuctions for extremities, respiratory systems, etc the same cannot be said of insects, some have as many as 100 legs while others don't even have legs. The distribution of energy and nutrients varies so much from one species of insect to another that we could easily divide all these into unique groups. Differences from lizard to lizard both genetically and anatomically are much larger than that of one mammal with another one (don't forget that birds have recently been included with this family). I dare say that the almost identical functioning of the mammal's physionomy makes it one if not the least diversed of all groups (even a whale has more in common with humans than a millipede with a ladybug).

[blazarwolf]

I've noticed lately how out of all the classes of the animal kingdom, that mammals appear to be the most diverse in anatomy and physiology.

 

Perhaps what you meant is a higher propensity to diversify across same numbers of generations? Perhaps due to higher brain structures allowing new niches to be exploited, and increasingly dynamic enviorment since KT requiring new niches to be exploited.

 

I find this particularly interesting since there are very few mammal species. Even more interesting to me is that mammals not only make up such a small group, but we have only been on this earth such a short time compared to most other animal groups such as insects, amphibians, reptiles, etc.

 

They are called lower animals for a reason, the latter two really are better adapted for an archeo enviorment

 

But as many kinds of insects there are, they all seem to have more in common anatomically to one another than the few mammal species do. Take, for example a mouse, a lion, an elephant, a bat, a whale, a giraffe , and a human. Now look at how drastically different all those animals look from each other.

 

Yeh, someone already pointed it out... Think body plan not size or looks. Why is a cetaceans tail fin horizontal and not vertical like fish? Insects are the most diverse as to body plans... This can be attributed to there fast turnover (generations)

 

Yet if you go back in time to before the dinosaurs went extinct just 65 mya, the common ancestor for humans and elephants (to my knowledge)looked like some rodent. Now you can go back hundreds of millions of years and find that a lot of groups of reptiles such as crocodilians and turtles which are still around today, were pretty much the same.

 

Crocadiles Specifically and turtles somewhat... Fill a very narrow niche and have gotten quite good at it.. Take them away and they are very unfit.

 

Same goes for fish and arthropod groups(by groups I mean classes,orders,families, genera,etc).

 

In general apperance somewhat true, there are many anatomical differences from the fossil record, and we know almost nothing in terms of physiology.

 

So what I would like to know is how have mammals, who are so young and so low in numbers have diversified so much so quickly?

 

65 my is along time, we kinda had a fresh start, were not young (idiana jones said "it aint the years its the milage")... make a lion t-rex size, which is scarier?

 

Is there something about mammals that are unique, or is there something I'm missing?

 

Theres alot about mammals that is unique, basically things got better, I doubt dinousars had the highly specialized nervous systems birds do, nor alot of other things about them... We are higher animals

[TrickyPeach]

What about reptiles? Dinosaurs, turtles, chameleons, crocodiles, frogs... they seem pretty diverse... it's a matter of perspective.

 

Also you are only looking at things on our scale, go smaller, go microscopic and you'll notice pretty much the most diverse lifeforms on earth can be found in the most diverse environments.

 

The way I see it: From reptiles birds and mammals evolved... nothing has yet to evolve from mammals.

Edited October 2, 2008 by TrickyPeach

[blazarwolf]

What about reptiles? Dinosaurs, turtles, chameleons, crocodiles, frogs... they seem pretty diverse... it's a matter of perspective.

 

Its about about ability to Adapt to new enviorments.

 

Also you are only looking at things on our scale, go smaller, go microscopic and you'll notice pretty much the most diverse lifeforms on earth can be found in the most diverse environments.

 

can be atrributed to turnover rate (generations)

 

The way I see it: From reptiles birds and mammals evolved... nothing has yet to evolve from mammals.

 

Hominoidea could be considerd a new class onto itself... we do many unique things..... ofcourse this includes humans, how does it not constitue new evolution? this can be traced to using sticks to get at termites perhaps? (also ripping off the genitals in combat )

Edited October 2, 2008 by blazarwolf
double word (to)

[TrickyPeach]

can be atrributed to turnover rate (generations)

and the fact they have been around longer!

 

Hominoidea could be considerd a new class onto itself... we do many unique things..... ofcourse this includes humans, how does it not constitue new evolution? this can be traced to using sticks to get at termites perhaps? (also ripping off the genitals in combat )

Yes, humans are special, one of the main reasons is our ability to have causal thought, the ripping off of anything does not make us a class.

We are mammals, check your breasts.

[blazarwolf]

check your breasts.

There too small! and my tounge cant reach there!

[TrickyPeach]

There too small! and my tounge cant reach there!

 

I would offer mine but society would think badly of me.

[npts2020]

Which society?

[TrickyPeach]

Which society?

 

The one in my head, they pressure me to do things I don't always like. They give me migraines...

[blazarwolf]

I would offer mine but society would think badly of me.

 

Sweet! I remember before adolesance, one of those wierd discussions... my mom said something like "girls dont like to have the titties suckled". I went up to the attic, pulled out her own aged book on human sexual expression. Booya! 2-5% become aroused, right there... Booya.

[TrickyPeach]

Sweet! I remember before adolesance, one of those wierd discussions... my mom said something like "girls dont like to have the titties suckled". I went up to the attic, pulled out her own aged book on human sexual expression. Booya! 2-5% become aroused, right there... Booya.

 

 

Girls probably don't, teenagers, probably might and women probably will enjoy it.

 

You do know that I was joking, right?

[blazarwolf]

Girls probably don't, teenagers, probably might and women probably will enjoy it.

 

You do know that I was joking, right?

 

Oh great female intellegence apon the organisation of girls/tennagers/women.... Of course its a joke, flirtings a joke on a internet forum, still a nice one (thats male deduction for you!)

[TrickyPeach]

Oh great female intellegence apon the organisation of girls/tennagers/women.... Of course its a joke, flirtings a joke on a internet forum, still a nice one (thats male deduction for you!)

 

I'm male too.

[blazarwolf]

I'm male too.

 

Oh great, now i feel gay... thats funny...

 

Disclaimer Edit: Becuase its actually funny! being a 22yo virgin with Jewy Asbergers does not make you gay (sry for the preconceptions/implications, it happens alot!, but yes very nice people)

Edited October 6, 2008 by blazarwolf