The problem of defining species

[shunyadragon]

The debate between scientist and fundamentalist creationists often revolves around the concept of species, and whether there is evidence of one species evolving to another species, or 'kinds' evolving into 'kinds.' Fifty years ago the evidence was indeed a bit sparse. All the known fossils of the primate ancestors could fit into a cardboard box, now they can fill a museum. We had only a few fossils of feathered dinosaurs, now we have thousands. The finds of new fossil and species(?) of dinosaurs in the past ten years or so has been even more impressive. The following article tells an interesting story. There are of course still gaps and unresolved questions, but the recent finds are extremely impressive.

From: New dinosaurs are being discovered in record numbers, and it’s changing everything we thought we knew
“It’s a nice little paper that shows that in the last 20 years, the number of dinosaur genera named, as well as the number of specimens of those genera, has increased greatly,” Jonathan P. Tennant, co-author of the work, explains. “This has profound impacts on our understanding of dinosaur diversity, especially as these discoveries are unevenly spread over time and space. There are still huge gaps in our knowledge of the fossil record, and areas in space and geological time where the rapid pace of discovery is changing much of what we thought we knew about dinosaurs.”

https://i1.wp.com/fossilsand****.com/wp-content/uploads/2018/02/Fig.-2-Genera-plot-through-time.png

You don’t have to look far to find examples of how an increase in dinosaur discoveries has shifted our knowledge. A few decades ago, the idea that some land-dwelling dinosaur species were covered in feathers was laughable at best. Crafty hunters like the velociraptors in Jurassic Park are depicted as leathery beasts, but we now know that the creatures were largely covered in plumage. Likewise, the mighty Tyrannosaurus rex was long thought to be the ultimate predator, but more recent discoveries have suggested it may have also been a scavenger, feasting on already-dead carcasses rather than hunting for a fresh feast when it was hungry.

There’s no telling what discoveries lie under the next rock, but scientists are painting a prehistoric picture faster and with more detail than ever before, and it’s quite exciting."

This thread will discuss how these discoveries and other discoveries have challenged out previous efforts to define species.

The fossils and genetic evidence collected over recent years has revealed the difficulty of drawing lines between species in human evolution, horses, various dinosaurs, and others which I will address.

In part I propose that evolution over time is more a continuum change and adaptation, and not the evolution of one species into another.

 

[Skwim]

In part I propose that evolution over time is more a continuum change and adaptation, and not the evolution of one species into another.

In that most creationists believe the evolution of a species operates in a comic book fashion:

I think this could be very helpful. Not that it's going to affect their big picture---it won't---but for those who are awake it may help them better understand how evolution progresses.

.

 

[Truly Enlightened]

The debate between scientist and fundamentalist creationists often revolves around the concept of species, and whether there is evidence of one species evolving to another species, or 'kinds' evolving into 'kinds.' Fifty years ago the evidence was indeed a bit sparse. All the known fossils of the primate ancestors could fit into a cardboard box, now they can fill a museum. We had only a few fossils of feathered dinosaurs, now we have thousands. The finds of new fossil and species(?) of dinosaurs in the past ten years or so has been even more impressive. The following article tells an interesting story. There are of course still gaps and unresolved questions, but the recent finds are extremely impressive.

From: New dinosaurs are being discovered in record numbers, and it’s changing everything we thought we knew
“It’s a nice little paper that shows that in the last 20 years, the number of dinosaur genera named, as well as the number of specimens of those genera, has increased greatly,” Jonathan P. Tennant, co-author of the work, explains. “This has profound impacts on our understanding of dinosaur diversity, especially as these discoveries are unevenly spread over time and space. There are still huge gaps in our knowledge of the fossil record, and areas in space and geological time where the rapid pace of discovery is changing much of what we thought we knew about dinosaurs.”

You don’t have to look far to find examples of how an increase in dinosaur discoveries has shifted our knowledge. A few decades ago, the idea that some land-dwelling dinosaur species were covered in feathers was laughable at best. Crafty hunters like the velociraptors in Jurassic Park are depicted as leathery beasts, but we now know that the creatures were largely covered in plumage. Likewise, the mighty Tyrannosaurus rex was long thought to be the ultimate predator, but more recent discoveries have suggested it may have also been a scavenger, feasting on already-dead carcasses rather than hunting for a fresh feast when it was hungry.

There’s no telling what discoveries lie under the next rock, but scientists are painting a prehistoric picture faster and with more detail than ever before, and it’s quite exciting."

This thread will discuss how these discoveries and other discoveries have challenged out previous efforts to define species.

The fossils and genetic evidence collected over recent years has revealed the difficulty of drawing lines between species in human evolution, horses, various dinosaurs, and others which I will address.

In part I propose that evolution over time is more a continuum change and adaptation, and not the evolution of one species into another.

Then you would be proposing half-truths. Speciation is when the continuum of changes and adaptive traits among members of the same species, over thousands of generations, become so genetically different, that a new species will emerge. This new species can't mate with members of his original species to produce a viable offspring. There are many factors that contribute to the changes that lead to speciation, not simply the environment or the organism's ability to adapt. Don

 

[Subduction Zone]

Then you would be proposing half-truths. Speciation is when the continuum of changes and adaptive traits among members of the same species, over thousands of generations, become so genetically different, that a new species will emerge. This new species can't mate with members of his original species to produce a viable offspring. There are many factors that contribute to the changes that lead to speciation, not simply the environment or the organism's ability to adapt. Don

Perhaps a qualifier should be added to your definition. There are examples of clearly different species interbreeding in captivity. In the wild such offspring would probably die out. But in the protected environment of a zoo or even personal ownership the offspring can get the care needed to grow to adulthood. Such matings are thought to be immoral due to the high rate of failure and the gentically troubled offspring created. A clear example are Tigons and Ligers. Tiger and lion hybrids. You can read why it is a practice that is more than frowned upon here:

Liger Facts | Big Cat Rescue

 

[Sapiens]

Then you would be proposing half-truths. Speciation is when the continuum of changes and adaptive traits among members of the same species, over thousands of generations, become so genetically different, that a new species will emerge. This new species can't mate with members of his original species to produce a viable offspring. There are many factors that contribute to the changes that lead to speciation, not simply the environment or the organism's ability to adapt. Don

Your critique founders on the reef of ring species.

 

[Hockeycowboy]

The debate between scientist and fundamentalist creationists often revolves around the concept of species, and whether there is evidence of one species evolving to another species, or 'kinds' evolving into 'kinds.' Fifty years ago the evidence was indeed a bit sparse. All the known fossils of the primate ancestors could fit into a cardboard box, now they can fill a museum. We had only a few fossils of feathered dinosaurs, now we have thousands. The finds of new fossil and species(?) of dinosaurs in the past ten years or so has been even more impressive. The following article tells an interesting story. There are of course still gaps and unresolved questions, but the recent finds are extremely impressive.

From: New dinosaurs are being discovered in record numbers, and it’s changing everything we thought we knew
“It’s a nice little paper that shows that in the last 20 years, the number of dinosaur genera named, as well as the number of specimens of those genera, has increased greatly,” Jonathan P. Tennant, co-author of the work, explains. “This has profound impacts on our understanding of dinosaur diversity, especially as these discoveries are unevenly spread over time and space. There are still huge gaps in our knowledge of the fossil record, and areas in space and geological time where the rapid pace of discovery is changing much of what we thought we knew about dinosaurs.”

You don’t have to look far to find examples of how an increase in dinosaur discoveries has shifted our knowledge. A few decades ago, the idea that some land-dwelling dinosaur species were covered in feathers was laughable at best. Crafty hunters like the velociraptors in Jurassic Park are depicted as leathery beasts, but we now know that the creatures were largely covered in plumage. Likewise, the mighty Tyrannosaurus rex was long thought to be the ultimate predator, but more recent discoveries have suggested it may have also been a scavenger, feasting on already-dead carcasses rather than hunting for a fresh feast when it was hungry.

There’s no telling what discoveries lie under the next rock, but scientists are painting a prehistoric picture faster and with more detail than ever before, and it’s quite exciting."

This thread will discuss how these discoveries and other discoveries have challenged out previous efforts to define species.

The fossils and genetic evidence collected over recent years has revealed the difficulty of drawing lines between species in human evolution, horses, various dinosaurs, and others which I will address.

In part I propose that evolution over time is more a continuum change and adaptation, and not the evolution of one species into another.

Question: how did velociraptors preen their feathers?

 

[Skwim]

Then you would be proposing half-truths. Speciation is when the continuum of changes and adaptive traits among members of the same species, over thousands of generations, become so genetically different, that a new species will emerge. This new species can't mate with members of his original species to produce a viable offspring. There are many factors that contribute to the changes that lead to speciation, not simply the environment or the organism's ability to adapt. Don

Well, sometimes they actually can. The coyote, Canis latrans, is a descendant of the wolf, Canis lupus, and both have mated to produce considerable populations of fertile wolf-coyote hybrids. Fertile hybrid offspring can even occur among animals so distantly related they belong to different genera. A prime example is the beefalo or cattalo, animals resulting from the mating of domestic cattle, Bos taurus, and the American bison, Bison bison.

.

 

[Truly Enlightened]

Thank you all, I stand corrected. Nature like myself, is not without exceptions. Don

 

[Subduction Zone]

The so called "species problem" is due to the fact that life is the product of evolution. If life was the product of "created kinds" then we would see a clear line between groups. Instead we see all sorts of exceptions of kinds as have been mentioned.l

The problem for creationists is that by the concept of "kind" man is the same kind as other apes. They can't have it both ways, but they try. Oh my do they try.

 

[shunyadragon]

Then you would be proposing half-truths. Speciation is when the continuum of changes and adaptive traits among members of the same species, over thousands of generations, become so genetically different, that a new species will emerge. This new species can't mate with members of his original species to produce a viable offspring. There are many factors that contribute to the changes that lead to speciation, not simply the environment or the organism's ability to adapt. Don

The discussion at this point is incomplete, and as far as the factors go that contribute to evolution the only other significant factors is the relationship with the biological community around the species which would part of the environment. The factors of the genetic ability to adapt is important, like the necessity of genetic diversity in populations

The emergent of a new species I do not consider an endpoint, but part of the continuum of change over time. Considering the existence today and in the increasing fossil evidence of sub-species, varieties and closely related species, the definition of what is a specific species becomes problematic. You may be able to look at the population at any one point in time as today or the fossil record and maybe define a species, but with time these lines become blurred. The vast amount of fossils discovered n the past ten years or so is beginning to reveal the problem for dinosaurs.

Actually closely related species are often capable of breeding, but usually do not because of environmental, isolation, and different evolved habits of the species.

 

[shunyadragon]

Question: how did velociraptors preen their feathers?

Much the same way birds do.

 

[Hockeycowboy]

Much the same way birds do.

Without beaks? How does that work?

 

[Subduction Zone]

Without beaks? How does that work?

What makes you think that they did not have beaks? Besides the teeth do you notice any significant difference between this velociraptor skull:

And this duck skull:

 

[Skwim]

Question: how did velociraptors preen their feathers?

Why do you assume they did? Just because birds do it doesn't mean velociraptors necessarily did.

.

 

[Hockeycowboy]

Why do you assume they did? Just because birds do it doesn't mean velociraptors necessarily did.

.

Feathers need constant care, without beaks it would be near impossible.....

 

[sayak83]

Feathers need constant care, without beaks it would be near impossible.....

Provide evidence. Show a study that says velociraptor's toothed jaws can't be used to preen the feathers it had.

 

[Skwim]

Feathers need constant care, without beaks it would be near impossible.....

Ah, and the feathers on a 75 to 71 million year old dinosaur were necessarily like today's bird feathers and needed such constant care because _________________________________________________________ . Thing is, you can't presume such things had to be true. On needs very good evidence to before making such assumptions. Perhaps in their evolutionary infancy feathers were quite unlike the feathers of today; feathers that didn't require any preening whatsoever.

.

 

[Hockeycowboy]

you can't presume such things had to be true. On needs very good evidence to before making such assumptions. Perhaps in their evolutionary infancy feathers were quite unlike the feathers of today; feathers that didn't require any preening whatsoever.

"I can't presume..... One needs very good evidence before making such assumptions" You are accusing me of this?

All the assumptions lie with you guys. I just question such low standards of evidence.

 

[Altfish]

I don't think Evolution has a problem defining species because if the boundaries between species are a bit fuzzy then evolution explains why that is.
Creation on the other hand....

 

[ADigitalArtist]

Birds appear in fossil records of the Cretaceous, at least 115 years ago. These supposed ancestors had to be older than what you've stated.

Velociraptors weren't the ancestors of birds. They're closely related via the common ancestor in eumaniraptora of the paraves line.
http://www.geol.umd.edu/~tholtz/G104/104Eumaniraptora.jpg

But there are several extinct avian dinosaurs with feathers that also had teeth. Including pelagornis.

Sorry if those image are big. Just had to share this goofy monster sea bird.
Anyway. Teeth don't stop preening, even with sea birds where feather care is even more important.