Updated: Sep 5
Modern whales and dolphins are mammals (giving their young milk) and mammals are four limbed (tetrapods) and usually terrestrial (land dwelling).
"The “problem”, of course, is that modern whales are emphatically not terrestrial, nor do they have four limbs–they have two front flippers and a tail, with no hind limbs in sight. Yet they are mammals, which forces evolution’s hand as it were. Evolution thus is dragged, under protest, to the prediction that modern whales, as mammals, are descended, with modification, from ancestral terrestrial, tetrapod ancestors...
And yet, these difficulties are the stuff of science. If indeed our “educated guess” of terrestrial, tetrapod ancestry for whales is correct, the evidence will show that these transitions, challenging though they may seem,
did indeed occur on the road to becoming “truly cetacean.”
~ Venema, Dennis. Whale Evolution:
theory, predication and converging lines of evidence. 2017. Biologos
Part 1: Living (Extant) Whales
Part 2: Whale Fossils (Extinct Whales)
Part 3: DNA and Whale Evolution
What About Objections?
Most objections seem to fall into just a few categories. Many unfortunately contain so many errors and misunderstandings about evolution and biology that it would be very difficult to begin to address the writings without attempting to correct all the misunderstandings first. Many quotes against whale evolution used are decades old and disproven or taken out of context.
Most in my experience will basically list all the adaptations and appeal to the reader with, “how could all this have happened” without addressing the evidence we DO have. Mechanisms of “how” are important but can’t negate the evidence of “what” we have. In addition, we do know in many cases how it happened by studying their genomes. Please be sure to see the "How vs. What" blog. See some of the applicable articles in the References section below.
The evidence for whale evolution is truly overwhelming as is the various scientific fields that all contribute to this huge body of supporting evidence: 1. Paleontological evidence
2. Morphological evidence
3. Molecular biological evidence
4. Vestigial evidence
5. Embryological evidence
6. Geochemical evidence
7. Paleoenvironmental evidence
8. Paleobiogeographic evidence
9. Chronological evidence
For a detailed discussion regarding the evidence from the above scientific fields, see: https://ncse.ngo/origin-whales-and-power-independent-evidence. See other sources in the References section also.
To dismiss the mountain peaks of whale evidence amounts to dismissing a mountain range of robust and sound evidence. To deny whale evolution from what has been scientifically discovered is now perverse.
An analogy is someone traveling to their vacation home only to find it completely destroyed. Pieces in front of them are on the ground, or more accurately what remains in this example. But what if we don’t know or are unsure how it was destroyed? Fire, hurricane, earthquake, tornado, angry neighbor, or gas leak? The fact of the event is independent of the “how” or mechanism. Would we really deny the fact of the home destruction until we knew exactly how it occurred, to our satisfaction, while dismissing the input from experts and the observations before our very eyes? So it is with whale evolution. We know it occurred because of the overwhelming evidence. It’s a great example of evolution and indeed “macroevolution”. One does not need to “be there”. One does not need to have every step worked out. Our courts certainly operate on the “what” even if the “how” is incomplete or even unknown. See “The Teacher’s Pet” case. When it comes to evolution we even have an idea of the hows.
Why would a deer like creature venture into the water? https://bigthink.com/surprising-science/ancient-deer-like-creatures-returned-to-the-ocean-to-become-whales-paleontologists-say/
I assert that the evidence for whale evolution is so broad and numerous that any person not committed to a previous position against it would agree that whales evolved as science has discovered. The evidence comes from at least three broad areas. Other evidence such as continental drift and the late Tethys Sea that was present at the time all impact on why whale evolution occurred when it did; it’s an amazing true story that brings in many areas of science and history all to a single conclusion. Objections rarely if ever address the copious evidence but instead attempt to throw doubt by appealing to intuition and mechanisms as the sole arbitrators regarding whale origins.
From: Ancient Archeology Secret
What is the Evidence for Evolution?
Prothero, Donald. 2017. Evolution: what the fossils say and why it matters. 2nd ed. Columbia University Press.
When Whales Walked. PBS Eons
The Evolution of Whales
Whale Evolution: Theory, Prediction and Converging Lines of Evidence
The Origin of Whales and The Power of Independent Evidence
The Evolution of Whales From Land to Sea
How Whale Genes Evolved to Produce Huge Sized Whale bodies
How Whales Evolved From Land to Water, Gene by Gene [85 pseudogenes]
How Paleontologists Pieced Together the Strange Story of Whale Evolution
The Origin and Early Evolution of Whales: Macroevolution Documented on the Indian Subcontinent. 2009. Bajpai, S., JGM Thewissen, and A.. Sahni. J. Biosci. 34(5). Indian Academy of Sciences. 678-686.
Ancient Whales Were the Biggest and Smallest of Their Kind to Ever Roam the Oceans. New discoveries show how whale diversity exploded after the dinosaurs disappeared. 2023. The Smithsonian.