The Big Picture
In this post on the subject of whales, I want to try and summarise my thoughts on whales and give a creationist view that is consistent with the evidence of design.
The fossil “archaeocetes” are presented as one of best examples of an evolutionary transition. In this case from fully terrestrial to fully marine creatures. It is believed that the ancestor of whales was some sort of artiodactyl (even toes hoofed animals like pig, deer and hippo). Hippos are aquatic artiodactyls. Currently evolutionists consider that Indohyus, was an aquatic artiodactyl which was closely related to the ancestor of whales. However, it is important to emphasise that there is no series of transitional fossils. The only feature which links Indohyus to whales is a part of the ear which is called the involucrum, which is thicker than in other animals. This is possibly related to underwater hearing. There were other extinct creatures with an involucrum (for example Pakicetus, Ambulocetus and Maiacetus). It is this feature which evolutionists point to when they claim that they are ancestors of whales.
Another part of the evolutionary account is the fact that fossils like Pakicetus, Ambulocetus and Maiacetus have ankle bones with a double pulley astragalus (ankle bone). This is a feature of artiodactyls. Therefore, these extinct creatures are considered to be artiodactyls. In addition, they are considered to be whales because of the involucrum.
Dorudon is also considered to be closely related to the ancestor of whales. This creature lived in the sea and had very small legs with the double pulley astragalus. This and other features of the skeleton and teeth are seen as evidence that creatures like Pakicetus, Ambulocetus and Maiacetus were ancestors of Dorudon.
It is clear that there was a group of extinct creatures which were paddle swimmers; Ambulocetus is a good example. These creatures appear to have been amphibious and would also have been able to walk on land. However, Pakicetus is considered by many to have been fully terrestrial. Although one expert of whale evolution (Philip Gingerich) considers that this reconstruction is erroneous because it is based on bones of a terrestrial creature that have been incorrectly referred to Pakicetus. According to Gingerich, Pakicetus was very similar to Ambulocetus.
If Pakicetus was indeed more similar to these amphibious creatures, then its status as a morphological intermediate, linking land animals to the paddle swimming creatures, is less obvious.
There appears to have been three different kinds of extinct creatures which had an involucrum. Terrestrial creatures like Indohyus, the amphibious paddle swimmers, like Ambulocetus (and also, according to Gingerich, Pakicetus) and fully marine creatures like Dorudon.
I believe that the morphological differences between these groups are considerable and there is no series of transitional fossils and therefore they are not an example of an evolutionary transition. There is an especially large gap, between extant whales and Dorudon, without any transitional fossils.
The extant whales are optimally designed for life in the sea and show many unique features which allow them to live in the oceans of this world. For most of these there are no credible evolutionary pathways.
These include:
• Streamlined shape
• Lack of hair
• Blubber (for insulation)
• Tail fluke (plus muscles and bones) for propulsion
• Flippers for directional control
• Heat exchanger circulatory system for the male testis and the female uterus
• Blowhole (with specialised muscles and nerves)
• Respiratory system designed for deep diving (oxygen storage, lung collapse, slow heart rate)
• Salt elimination system
• Underwater birth and suckling
In addition to many shared featured, echolocation and teeth are key features of the odontocetes and baleen is a defining feature of the mysticetes.
As creationist I think it is reasonable to consider that the fossils evidence is consistent with the concept of distinct basic types or created kinds specifically designed for life in different environments.
As a working hypothesis I would like to suggest the following:
The creatures which are presented as members of a fossil series showing the evolution of whales are in fact members of three basic types of creatures:
• Terrestrial creatures, with an involucrum (e.g. Indohyus)
• Amphibious paddle swimmers, with an involucrum and double pulley astragalus (e.g. Pakicetus, Ambulocetus, Maiacetus, Protocetus, and similar creatures).
• Toothed marine creatures with small legs that possibly functioned as claspers during mating (e.g. Dorudon and Basilosaurus)
Each of these extinct basic types is defined by a unique set of features and were designed for a specific life-style; terrestrial, amphibious and marine.
Today there are only two (possibly more) basic types of extant whales; the mysticetes (baleen whales) and odontocetes (toothed whales).