Genetics shows that microevolution is true but it is hard for us to appreciate the whole picture because of our fraction of time spent on this planet in relation to the time needed for large macroevolution changes. Sure we can look at speciation in the lab with bacteria and such but people want to see larger animals, mammals, and humans to be convinced. So, do we have evidence for macroevolution? You betcha! Museums around the world are filled with thousands upon thousand of fossils showing transitional changes. Here is a select few examples showing some of the transitions we understand deeply, including the transition from water to land and from reptiles to mammals.
One of the key points to remember about fossils is that you can make predictions of where in the strata layer you can find a species. For the most part you find oldest layers being at the bottom and younger layers being at the top. And again as a point, no species has ever been found in the wrong strata layer. One way to completely debunk evolution is to find a species in the wrong order. Dawkins says the creationists should be out frantically digging up fossils to find one out of place if they want to hold to their creation and flood myth.
One of the reasons people have a hard time accepting evolution is the transition of species from water onto land. It is now well documented and understood as we now have a good amount of fossils showing the transition. In 2004, Neil Shubin made the critical discovery of the Tiktaalik, being the main transition species between water and land. Shubin was able to make predictions of what strata layer he might find this transitional species based on what layers more fish like species and more tetrapod like species lay in. And anybody could have guessed it, right smack dab in the middle! Tiktaalik's fins had more shoulder, elbow, wrist like features suggesting that it was able to lift it self up out of the water like a push-up. So here is our current understanding of great transition from water to land:
Next up we have the transitional fossils that fill in the gaps between reptiles and mammals. This fossil sequence shows how the reptilian jaw developed into the mammalian ear. Additional evidence has even shown that the same embryonic structures in the reptile also develop into the ear of mammals:
A bit of odd evolutionary history is that modern dolphins porpoises, and whales evolved from land mammals. Another clue was looking at the
swimming biomechanics compared to other fish. Most fish have a side to side swimming stroke where as most land animals like otters that enter the water have an up and down swimming stroke. It goes to show that dolphins,
porpoises, and whales have an up and down swimming stroke. Even further evidence is the
vestigial hind limbs in whales. They still have the genetic code to build hind limbs but the gene is switched off early on leaving small femur like bones that can be seen on any whale fossil.
