Mammals evolving from birds rather than reptiles.

  • Thread starter Jupiter60
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In summary, this guy thinks that mammals evolved from birds, and that this is a more convergent evolution than the evolution of birds from reptiles.
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  • #2
Jupiter60 said:
Could mammals have actually evolved from birds?
Cynodonts, an ancestor of modern mammals had been living 110 million years before archaeopteryx did.
 
  • #3
Jupiter60 said:
Apparently this guy thinks mammals evolved from birds rather than reptiles.

http://www.evolutionem.co.uk/btm106.html

http://www.evolutionem.co.uk/btm107.html

He points out the similarities between birds and monotremes. What do you think about the idea? Could mammals have actually evolved from birds?
Depends on how far back you go.

This is a picture of everybody's great-great-great- ... -great-great-great grand daddy:

Dimetrodon_grandis.jpg

Dimetrodon was a creature which is grouped into what are known as synapsids, due to the construction of their skulls. Synapsids pre-date reptiles as we know them today, but the synapsid line split into two main groups, one group which evolved into sauropsids, which eventually became modern reptiles and birds, and the other group which led to early mammals and eventually present-day mammals.

https://en.wikipedia.org/wiki/Mammal

I'm not aware of any scientist who advocates credibly that mammals, including monotremes, evolved from birds or their early reptile-like ancestors. From the fossil record, any evolvin' of birds and monotremes appears to have occurred along separate lines in time. The duck bill and the egg-laying of the platypus appear to be an evolutionary coincidence.
 
  • #4
SteamKing said:
The duck bill and the egg-laying of the platypus appear to be an evolutionary coincidence.
I think this is what evolutionists term as convergent evolution.
 
  • #5
blue_leaf77 said:
I think this is what evolutionists term as convergent evolution.
Yeah, that's the ticket.
 
  • #6
SteamKing said:
php?image=https%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2F5%2F5e%2FDimetrodon_grandis.jpg

That actually looks like my great aunt after she quit smoking about 15 years ago :confused:
 
  • #7
DNA evidence refutes the possibility that mammals evolved from birds:
Initially, some gene sequences suggested a close relationship between birds and mammals, although never with strong statistical support (e.g., Bishop & Friday, 1987; Goodman et al., 1987; Hedges et al., 1990). More recently, a study of the molecular evidence for the origin of birds (15 genes; 5280 nucleotides, 1461 amino acids) discovered strong support (100% bootstrap P value, BP) for a close relationship between birds and crocodilians (Hedges, 1994). A smaller data set of 11 transfer RNA genes (686 sites) also resulted in a bird-crocodilian grouping (Kumazawa & Nishida, 1995). A basal position for mammals was supported (99% BP) by analysis of a 3 kilobase portion of the mitochondrial genome containing the two ribosomal RNA genes (Hedges, 1994).
(http://tolweb.org/Amniota/14990)

In other words, if you look at shared gene sequences between birds, mammals, repltiles, and other amniota, it's clear that mammals and all of their relatives fall on one branch and reptiles and birds fall on the other branch:
amniota61.png

These relationships are supported by the synapsids fossils referenced by SteamKing above.

Here's a link to the Hedges 1994 study referenced in the quote that refutes the mammal-bird connection: http://www.pnas.org/content/91/7/2621.long
 
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  • #8
But seriously folks...

SteamKing said:
I'm not aware of any scientist who advocates credibly that mammals, including monotremes, evolved from birds or their early reptile-like ancestors. From the fossil record, any evolvin' of birds and monotremes appears to have occurred along separate lines in time.

Yeah, I'd have to agree with this. At least from the perspective of brain evolution, mammals and birds took two fundamentally different paths in their development of advanced brain structures over their more ancestral forms. The mammalian brain evolved a neocortex out of the dorsal pallium of the amphibian-reptile primordial structure, while the avians developed a hyperstriatum out of the more subcortical dorsal ventricular ridge. These are two distinct paths of evolution.
 
  • #9
blue_leaf77 said:
I think this is what evolutionists term as convergent evolution.

Why would you think this was more convergent versus divergent evolution? The monotremes including the platypus and the echidna are the most primitive of egg laying mammals next to the egg-laying reptiles. Doesn't this make sense that these are species diverging in their evolution from their reptilian ancestors rather than converging from who and what knows where? Where is this converging egg laying behavior and duck-billed phenotypy coming from?
 

1. How do scientists explain the theory of mammals evolving from birds rather than reptiles?

The theory of mammals evolving from birds rather than reptiles is based on the study of fossils, anatomical similarities, and genetic evidence. It suggests that early mammal-like reptiles, called synapsids, evolved into early birds, known as theropod dinosaurs, before diversifying into modern mammals.

2. What is the evidence for mammals evolving from birds rather than reptiles?

The evidence for this theory includes the discovery of transitional fossils, such as Archaeopteryx, which had both reptilian and bird-like features. Additionally, there are many anatomical similarities between birds and mammals, including the structure of their skulls and inner ear bones. Genetic studies have also shown a closer evolutionary relationship between birds and mammals.

3. How does the timeline of mammal evolution support the theory of mammals evolving from birds rather than reptiles?

The timeline of mammal evolution supports this theory as it shows that early mammals and early birds existed during the same time period, with the earliest birds appearing before the first mammals. This suggests that the two groups shared a common ancestor and that birds evolved from reptile-like mammals.

4. What about the fact that birds are warm-blooded and reptiles are cold-blooded?

The difference in body temperature between birds and reptiles does not necessarily disprove the theory of mammals evolving from birds. It is believed that early mammals and early birds both had warm-blooded characteristics, which helped them survive in a changing environment. As they evolved, birds developed more efficient ways to maintain their body temperature, while mammals evolved other traits, such as hair and milk production, for survival.

5. Is the theory of mammals evolving from birds rather than reptiles widely accepted among scientists?

While there is still ongoing research and debate on the exact evolutionary path of mammals and birds, the theory of mammals evolving from birds rather than reptiles is widely accepted among scientists. The evidence from fossils, anatomy, and genetics all support this theory, and it is currently the most widely accepted explanation for the evolution of these two groups.

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