What inferences can we make by looking at these two specimins?

[Sherlock Holmes]

For example, what might their nearest common ancestor look like? might their DNA be similar? if we found these only as fossils, what might we infer?

 

[alang1216]

For example, what might their nearest common ancestor look like? might their DNA be similar? if we found these only as fossils, what might we infer?

View attachment 1002279

Not an anatomist but I'll play:

• carnivore
• swift
• mammalian (probably)

The nearest common ancestor likely looked very similar.

 

[sealybobo]

For example, what might their nearest common ancestor look like? might their DNA be similar? if we found these only as fossils, what might we infer?

View attachment 1002279

Dog

 

[Muhammed]

For example, what might their nearest common ancestor look like? might their DNA be similar? if we found these only as fossils, what might we infer?

View attachment 1002279

They look like wolves to me. Or maybe the one on the right is a wolf and the one on the left is a domesticated dog.

 

[Grumblenuts]

dingo
coyote
I win. Now what do we do? Game over, man. Game over!

 

[ReinyDays]

Look at how the femurs attach to the pelvis ... the left is mammalian and the right is definitely reptilian ... so the common ancestor would be the Amniotes ≈ 300,000,000 years ago ... the DNA would be an almost exact duplicate, there's not that much variety in the tetrapod lineage ... and what would I think if I found these fossils? ...

[ka'ching] ...

I'd immediately start counting chickens before they hatch ... that's just how rare fossil Amniotes are ...

Amniote - Wikipedia

en.wikipedia.org

 

[Sherlock Holmes]

I'm still waiting for our erudite knowall Fort Fun Indiana to venture an opinion, why is he so afraid I wonder.

 

[scruffy]

I'm still waiting for our erudite knowall Fort Fun Indiana to venture an opinion, why is he so afraid I wonder.

Troll. ^^^

 

[Sherlock Holmes]

The point being made by this thread is to show that appearances are sometimes deceptive, one image is a coyote (a mammal) and the other a thylacine (a marsupial).

Skeletal similarities though - in the absence of further information - would mislead an evolutionist because morphological similarity is often used to infer genetic similarity and hence relatedness.

We can see many examples of this kind of reasoning in the fossil record, the assumption that X and Y LOOK closely related and therefore ARE closely related, but as you can see here, this can very easily be a huge error of judgement.

The fossil record is (like all evidence) interpreted and we have no idea just how correctly it's been interpreted so far.

 

[Grumblenuts]

one image is a coyote (a mammal) and the other a thylacine (a marsupial).

Source? You don't actually believe anyone, well, other than ding, is apt to just take your word it?

 

[Fort Fun Indiana]

Is anyone here a paleontologist or biologist?

Then I would say nobody here can make a single useful inference, which is of cource why you posted it here.

 

[ReinyDays]

The point being made by this thread is to show that appearances are sometimes deceptive, one image is a coyote (a mammal) and the other a thylacine (a marsupial).

Skeletal similarities though - in the absence of further information - would mislead an evolutionist because morphological similarity is often used to infer genetic similarity and hence relatedness.

We can see many examples of this kind of reasoning in the fossil record, the assumption that X and Y LOOK closely related and therefore ARE closely related, but as you can see here, this can very easily be a huge error of judgement.

The fossil record is (like all evidence) interpreted and we have no idea just how correctly it's been interpreted so far.

Marsupials are Mammals ... what you mean is one is from the Carnivoramorpha clade and the other from the Marsupialia clade ... fooled me ... looks like bird hips to uneducated construction laborers ... go dig your own ditches if you don't like it ...

Much of what we know about marsupials comes from Steve Irwin, the funny guy on TV, he also was a dedicated naturalist and basically founded the science of Marsupial Zoology ... or so I'm told ...

 

[Sherlock Holmes]

Marsupials are Mammals ... what you mean is one is from the Carnivoramorpha clade and the other from the Marsupialia clade ... fooled me ... looks like bird hips to uneducated construction laborers ... go dig your own ditches if you don't like it ...

Much of what we know about marsupials comes from Steve Irwin, the funny guy on TV, he also was a dedicated naturalist and basically founded the science of Marsupial Zoology ... or so I'm told ...

Well said, my apologies, indeed a marsupial is a mammal - my mistake!

 

[ReinyDays]

Well said, my apologies, indeed a marsupial is a mammal - my mistake!

But still a good thread ... these lineages are quite distant ... it's a successful layout, first we're up out of the water and away from sharks, talk about important survival techniques ...

I'm going to guess the hip rotation was needed for bearing larger young ... marsupial fetuses have to crawl into their mother's pouch to get at the teats ... for protection ... so smaller exit-size allows for more primordial hip structures, carnivores and us rodents needed a different set up ... if you believe in evolution ...

 

[Fort Fun Indiana]

This is a nice example of convergent evolution.

Their last common ancestor was in the Jurrasic.

 

[Sherlock Holmes]

This is a nice example of convergent evolution.

Their last common ancestor was in the Jurrasic.

But one could never assert that if all we had were fossils, the assumption would be (because it always is) that they were closely related and divergent.

 

[Fort Fun Indiana]

But one could never assert that if all we had were fossils, the assumption would be (because it always is) that they were closely related and divergent.

I can't make heads or tails of this comment. Could you rephrase?

 

[Fort Fun Indiana]

But one could never assert that if all we had were fossils, the assumption would be (because it always is) that they were closely related and divergent.

Not so. We are very good at physiology. The differences in the marsupial skeleton would be noticed. It would be obvious that it was not like other canids.

This is how we have discovered other instances of convergent evolution in the fossil record among exitinct species.

 

[dblack]

Here's one I find interesting: The ancestors of modern whales ---

 

[progressive hunter]

Look at how the femurs attach to the pelvis ... the left is mammalian and the right is definitely reptilian ... so the common ancestor would be the Amniotes ≈ 300,000,000 years ago ... the DNA would be an almost exact duplicate, there's not that much variety in the tetrapod lineage ... and what would I think if I found these fossils? ...

[ka'ching] ...

I'd immediately start counting chickens before they hatch ... that's just how rare fossil Amniotes are ...

Amniote - Wikipedia

en.wikipedia.org

when you say common ancestor do you mean it gave birth to two different types of animals,, one a mammal and the other a reptile??