Why evolution is true

[Spud]

Spud seems to take the view that we see with our eyes. If he had any understanding of neuroscience he would know that the eye is is the receptor of light-based information and that the processing of visual information takes place in - among other locations - the visual cortex in the occipital lobe of the brain.

The brain is our organ of vision, it perceives and creates our understanding of the world. Our eyes are merely cameras.

I do know a bit about the optic nerve and visual cortex. Are you saying they are poorly designed too?

How does it support that view?

By showing that flight didn't gradually evolve, as also in bats and birds. Wings appear suddenly, fully capable of flight.

[Maeght]

I would imagine primitive insect wings would be hard to spot in a fossil but that's just off the top of my head with nomparticular knowledge. I do know however that the fossil record does show a gradual evolution of feathers and wings so think you extrapolation from insects to all flighing creatures is incorrect.

[Spud]

so think you extrapolation from insects to all flighing creatures is incorrect.

Not what I said.
Flying insects first appear with fully formed wings.
Flying bats first appear with fully formed wings.
Flying birds first appear with fully formed wings.

[Maeght]

Not what I said.
Flying insects first appear with fully formed wings.
Flying bats first appear with fully formed wings.
Flying birds first appear with fully formed wings.

You said wings appear suddenly, fully capable of flight. This is true in someway in that something cannot be described as a wing unless it lets you fly, but the fossil record for birds shows an evolution of pre wings (if you like) which could not sustain flight. Feathered dinosaurs which couldn't fly evolving into birds which can.

[Sebastian Toe]

Not what I said.
Flying insects first appear with fully formed wings.
Flying bats first appear with fully formed wings.
Flying birds first appear with fully formed wings.

Are non flying birds related to flying ones?

[Spud]

You said wings appear suddenly, fully capable of flight.

When I said that, I was thinking that archaeopteryx, which could fly (although may have had to jump off something high to get airborne) dates to 150 million years old: older than a lot of the flightless feathered theropods it is thought to have evolved from. So in that sense, bird flight appears quite suddenly. The pre-wings you mention are interesting, as their feathers could not provide lift, however the same is true of ostrich feathers. Ostriches use their wings as stabilizers when they run. Maybe the flightless winged theropods did also?

This is true in someway in that something cannot be described as a wing unless it lets you fly, but the fossil record for birds shows an evolution of pre wings (if you like) which could not sustain flight. Feathered dinosaurs which couldn't fly evolving into birds which can.

[Spud]

Are non flying birds related to flying ones?

Ostriches and emus etc seem to have descended from even bigger flightless birds, so probably not, in their case.

[Spud]

Note that the two earliest flying insect fossils are of a mayfly and a giant dragonfly.
The earliest known bat fossil was fully capable of flight.

[SteveH]

When I said that, I was thinking that archaeopteryx, which could fly (although may have had to jump off something high to get airborne) dates to 150 million years old: older than a lot of the flightless feathered theropods it is thought to have evolved from. So in that sense, bird flight appears quite suddenly. The pre-wings you mention are interesting, as their feathers could not provide lift, however the same is true of ostrich feathers. Ostriches use their wings as stabilizers when they run. Maybe the flightless winged theropods did also?

It's not certain that archaeopteryx could fly; it may only have been able to glide.

[Maeght]

Note that the two earliest flying insect fossils are of a mayfly and a giant dragonfly.
The earliest known bat fossil was fully capable of flight.

If an earlier ancestor of the earliest bats couldn't fly would it be considered a bat? If it didn't show wings etc suitable for flight would it be a bat?

[SteveH]

If an earlier ancestor of the earliest bats couldn't fly would it be considered a bat? If it didn't show wings etc suitable for flight would it be a bat?

Quite. Fundies often use artificial human classifications to make this sort of claim. They say, for example, that archaeopteryx was a true, fully-developed bird, because we classify it as a bird, despite the fact that it had teeth, claws on its wings, and a bony tail. It is obviously transitional, but because biologists don't have a category called "dinobird", it gets lumped in with true, fully-evolved, later birds.
https://en.wikipedia.org/wiki/Evolution_of_birds

[Spud]

It's not certain that archaeopteryx could fly; it may only have been able to glide.

Recent research shows it had wing bones with a structure more similar to pheasants than to theropods, suggesting it did flap in some way:
https://www.nature.com/articles/s41467-018-03296-8

It also had a feather structure similar to modern birds, with interlocking barbules that strengthen them:
https://phys.org/news/2012-01-winged-dinosaur-archaeopteryx-flight.html

There are other fossils which show that flight was advanced by 130 mya: Archaeornithura meemannae, and Iberomesornis, 125 mya.

I have looked for an ancestor of Archaeopteryx, which is older than the Chinese feathered Sinornithosaurus, microraptor etc, but haven't found a clear transitional between it and the dinosaurs. Maybe you know?

If an earlier ancestor of the earliest bats couldn't fly would it be considered a bat? If it didn't show wings etc suitable for flight would it be a bat?

I guess people would call it something like "protobat"! Not sure what your point is though, as there doesn't seem to be such an ancestor?

[Maeght]

I guess people would call it something like "protobat"! Not sure what your point is though, as there doesn't seem to be such an ancestor?

The point is that a creature will only be referred to as a bat if it shows the characteristics of a bat such as being able to fly. If it doesn't it won't be referred to as a bat, even if it shows proto wings. So saying early bats could fly sort of comes with the definition of a bat.

[SteveH]

Recent research shows it had wing bones with a structure more similar to pheasants than to theropods, suggesting it did flap in some way:
https://www.nature.com/articles/s41467-018-03296-8

It also had a feather structure similar to modern birds, with interlocking barbules that strengthen them:
https://phys.org/news/2012-01-winged-dinosaur-archaeopteryx-flight.html

There are other fossils which show that flight was advanced by 130 mya: Archaeornithura meemannae, and Iberomesornis, 125 mya.

I have looked for an ancestor of Archaeopteryx, which is older than the Chinese feathered Sinornithosaurus, microraptor etc, but haven't found a clear transitional between it and the dinosaurs. Maybe you know?

Archaeopteryx is transitional between birds and dinosaurs! That's why some creationosts once wasted much time and energy trying to dismiss it as a forgery. They seem to have given that up now. Fossilisation is a rare event: the vast majority of creatures leave no trace. It is therefore not surprising that we don't have fossils of every single stage in the transition.

[Spud]

Archaeopteryx is transitional between birds and dinosaurs!.... 

Fossilisation is a rare event: the vast majority of creatures leave no trace. It is therefore not surprising that we don't have fossils of every single stage in the transition.

Archaeopteryx may not be classified as a bird, due to its dinosaur-like traits.

My point is that it could fly. (Several features suggest this, including a humerus bone that was similar in structure to a pheasant's; feathers that were similar to modern flight feathers; a well developed visual cortex and cerebellum, a furcula and a (albeit small) sternum).

There are no intermediates between the down feathers and the flight feathers; between flyers and non-flyers; it's up to each individual if you want to believe they existed, but the evidence suggests that all flying insects, mammals, and birds appear suddenly without intermediates in the record.

(Just to add: the "Coelurosaurs", that is, Velociraptor, Deinonychus, Sinosauropteryx, Sinornithosaurus, Caudopteryx, Microraptor, are all later than Archaeornithura meemannae, a fully capable flier dated at 130.7 my. So they can't be transitionals between non-fliers and fliers.)

[Maeght]

I think the Wikipedia article sums it all up well.

https://en.m.wikipedia.org/wiki/Flying_and_gliding_animals

[Spud]

I think the Wikipedia article sums it all up well.

https://en.m.wikipedia.org/wiki/Flying_and_gliding_animals

And I think I have read enough fiction for at least a week!

[BeRational]

People who deny evolution are in the same league as those that deny the Earth is a sphere.

It's not worth discussing it with them.

This topic is not up for discussion, it is now accepted.

It could be overturned of course, but only with evidence, and not personal incredulity, which is all that's on show.

You find it hard to believe, okay, I sympathise, now what?

[Dicky Underpants]

People who deny evolution are in the same league as those that deny the Earth is a sphere.

It's not worth discussing it with them.

This topic is not up for discussion, it is now accepted.

It could be overturned of course, but only with evidence, and not personal incredulity, which is all that's on show.

You find it hard to believe, okay, I sympathise, now what?

Oh, let's not give up on Spud yet! Since we've been discussing transitional fossils, I'd like to hear his pearls of wisdom about Tiktaalik. It is particularly significant that this fossil was found in the very type of geological strata and global location that one would have expected such a creature to be found, and I think that can't be just coincidence.

[Spud]

I'm just stating facts from the fossil record that I've found by researching online - they are glossed over in Maeght's link. Nobody denies microevolution, it is an interesting subject, as long as the data is interpreted correctly. Macroevolution is indeed accepted by this generation, but maybe a future generation wil think differently?

Oh, let's not give up on Spud yet! Since we've been discussing transitional fossils, I'd like to hear his pearls of wisdom about Tiktaalik. It is particularly significant that this fossil was found in the very type of geological strata and global location that one would have expected such a creature to be found, and I think that can't be just coincidence.

Will get back to you.

[Maeght]

And I think I have read enough fiction for at least a week!

Been on all those creationist websites again have we?

[Spud]

Been on all those creationist websites again have we?

If you have I'm happy for you, hope they helped 

[Maeght]

If you have I'm happy for you, hope they helped 

I take a look occasionally for a laugh.

[SteveH]

And I think I have read enough fiction for at least a week!

Why is it fiction?

[Spud]

Why is it fiction?

Because it claims that creatures have evolved flight (six times in the first paragraph) but the claim is wrong because of missing links (#314). It even states they don't know how any of it happened.