In the world of science evidence is of primary importance. When Einstein first proposed the concept of gravity bending space and the effect it should have on light itself, it took experimentation and the acquisition of evidence to convince a number of physicists of his day. And rightly so. Evidence is key.
The same critical thinking skills are required in the field of evolution. Fossil evidence is difficult to find simply due to the fact that we expect to find petrified remains of biological tissue embedded in the lithosphere. Yes the lithosphere seems stable enough throughout a human lifespan but archeologists search for fossils that are hundreds of millions of years old. The lithosphere is not as stable over this period of time.
Yet we do find some amazing fossils that support current evolutionary thought. Although many a creationist will claim there are no transitional fossils [a lie perpetuated via lack of investigation] science has unearthed a great number of these transitional fossils. An easy to find list exists at wikipedia.
Just recently a new discovery has been unearthed in Pakistan. The fossil contains the remains of two organisms, one reportedly male the other a pregnant female, showing the transition from land based mammal to water based mammal. They have short limbs showing these organisms spent time on land but also in aquatic environments. They are an ancestor of the modern whale.
The entire scientific report, with diagrams and photographs are available through PLOSone. PLOSone is an open source, free scientific journal that has greatly increased its impact factor in the sciences over the last year.
If you are a biology teacher this is a great chance to show your students a ‘real’ report of a significant find.