Charles Darwin was a noble and humble man. He recognized that his greatest contribution to science could still be just a mere fantasy. In his book On the Origin of Species he acknowledged that the lack of evidence for transitional fossils was "the most obvious and gravest objection which can be urged against my theory". This is the true sign of a scientist; one that formulates an idea and then seeks to be proven wrong.
Here's just 3 examples of the many species that existed that show a clear trend in the evolution of species. These examples illustrate how species had characteristics 'borrowed' from what we nowadays recognize as two clearly different species.
Previously interpreted as the world's oldest spider, Attercopus fimbriunguis belongs to an extinct order of arachnids named Uraraneida, thought to be close to the origins of spiders. Attercopus can be envisaged as a spider-like animal able to produce silk, but which lacked true spinnerets and retained a segmented abdomen bearing a flagellum-like tail resembling that of a whip scorpion.[1]
The shape of the skull and the fact that the feet face forward rather than outward indicate that Pederpes was well adapted to land life. It is currently the earliest known fully terrestrial animal, although the structure of the ear shows that its hearing was still much more functional underwater than on land, and may have spent much of its time in the water and could have hunted there.[2]
Gerobatrachus, also referred to as a frogamander, is an extinct genus of amphibamid temnospondyl that lived in the Permian period, approximately 290 million years ago, in the area that is now Baylor County, Texas. The animal has been interpreted as a concrete example for the hypothesis offered by many cladistic analyses that frogs and salamanders had a common ancestor, and that they are only distantly related to the third extant order of amphibians, the caecilians. Gerobatrachus has been considered to be the closest relative of Batrachia, the clade that includes modern amphibians.
Gerobatrachus combines features found later in frogs, such as a large space for a tympanic ear— an "ear drum"— and two ankle bones that are fused together, a typical salamander trait. Its backbone and teeth show features common to both frogs and salamanders, with a wide, lightly built skull similar to that of a frog.[3]
[1]http://en.wikipedia.org/wiki/Attercopus
[2]http://en.wikipedia.org/wiki/Pederpes
[3]http://en.wikipedia.org/wiki/Gerobatrachus
Here's just 3 examples of the many species that existed that show a clear trend in the evolution of species. These examples illustrate how species had characteristics 'borrowed' from what we nowadays recognize as two clearly different species.
Attercopus fimbriunguis
![[Image: tumblr_ly6ahnZoxc1qgxyxw.jpg]](https://images.weserv.nl/?url=media.tumblr.com%2Ftumblr_ly6ahnZoxc1qgxyxw.jpg)
![[Image: tumblr_ly6ahnZoxc1qgxyxw.jpg]](https://images.weserv.nl/?url=media.tumblr.com%2Ftumblr_ly6ahnZoxc1qgxyxw.jpg)
Previously interpreted as the world's oldest spider, Attercopus fimbriunguis belongs to an extinct order of arachnids named Uraraneida, thought to be close to the origins of spiders. Attercopus can be envisaged as a spider-like animal able to produce silk, but which lacked true spinnerets and retained a segmented abdomen bearing a flagellum-like tail resembling that of a whip scorpion.[1]
Pederpes
![[Image: Pederpes-m.jpg]](https://images.weserv.nl/?url=planetearth.nerc.ac.uk%2Fimages%2Fuploaded%2Fmedium%2FPederpes-m.jpg)
![[Image: 100815.JPG]](https://images.weserv.nl/?url=www.huntsearch.gla.ac.uk%2Fgeoimages%2F100815.JPG)
![[Image: Pederpes-m.jpg]](https://images.weserv.nl/?url=planetearth.nerc.ac.uk%2Fimages%2Fuploaded%2Fmedium%2FPederpes-m.jpg)
The shape of the skull and the fact that the feet face forward rather than outward indicate that Pederpes was well adapted to land life. It is currently the earliest known fully terrestrial animal, although the structure of the ear shows that its hearing was still much more functional underwater than on land, and may have spent much of its time in the water and could have hunted there.[2]
Gerobatrachus
![[Image: 250px-Gerobatrachus_NT.jpg]](https://images.weserv.nl/?url=upload.wikimedia.org%2Fwikipedia%2Fcommons%2Fthumb%2Fe%2Fed%2FGerobatrachus_NT.jpg%2F250px-Gerobatrachus_NT.jpg)
![[Image: Gerobatrachus.jpg]](https://images.weserv.nl/?url=www.fossilscience.com%2FImages%2FGerobatrachus.jpg)
![[Image: 250px-Gerobatrachus_NT.jpg]](https://images.weserv.nl/?url=upload.wikimedia.org%2Fwikipedia%2Fcommons%2Fthumb%2Fe%2Fed%2FGerobatrachus_NT.jpg%2F250px-Gerobatrachus_NT.jpg)
![[Image: Gerobatrachus.jpg]](https://images.weserv.nl/?url=www.fossilscience.com%2FImages%2FGerobatrachus.jpg)
Gerobatrachus, also referred to as a frogamander, is an extinct genus of amphibamid temnospondyl that lived in the Permian period, approximately 290 million years ago, in the area that is now Baylor County, Texas. The animal has been interpreted as a concrete example for the hypothesis offered by many cladistic analyses that frogs and salamanders had a common ancestor, and that they are only distantly related to the third extant order of amphibians, the caecilians. Gerobatrachus has been considered to be the closest relative of Batrachia, the clade that includes modern amphibians.
Gerobatrachus combines features found later in frogs, such as a large space for a tympanic ear— an "ear drum"— and two ankle bones that are fused together, a typical salamander trait. Its backbone and teeth show features common to both frogs and salamanders, with a wide, lightly built skull similar to that of a frog.[3]
So far, our geological records have provided evidence for the theory of evolution, hence why the theory hasn't altered to provide a better understanding.
[1]http://en.wikipedia.org/wiki/Attercopus
[2]http://en.wikipedia.org/wiki/Pederpes
[3]http://en.wikipedia.org/wiki/Gerobatrachus
"It is the mark of an educated mind to be able to entertain a thought without accepting it" ~ Aristotle