WHEEEEE ! Whale Evolution: Different Lines of Evidence by Larry Flammer - ENSI webmaster http://www.indiana.edu/~ensiweb/home.html http://www.indiana.edu/~ensiweb/lessons/whale.ev.html (Becoming Whales: Discovery of Whale Fossils) http://www.indiana.edu/~ensiweb/lessons/wh.a%26d.les.html (Whale Ankles and DNA) WHEEEEE !

What are we Doing Today? Whale fossil hunt Whale ankle comparisons Whale DNA comparisons WHALE EVOLUTION

Becoming Whales

Diversity of Whales Today Mysticetes (baleen whales):

Diversity of Whales Today Odontocetes (toothed whales):

But Where Did They Come From? ONE OF DARWIN’S IDEAS… … I can see no difficulty in a race of bears being rendered, by natural selection, more and more aquatic in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale. Charles Darwin, The Origin of Species, 1859 (first edition), Chapter 6: Difficulties on Theory Darwin was wrong about the BEAR (he removed this idea in later editions), but spot-on with the process – NATURAL SELECTION.

Here’s a Peek into the Past… So, Where DID Whales Come From? Here’s a Peek into the Past…

Moving in… Notice that the earliest MAMMALS… were TERRESTRIAL - with LEGS !

But WHALES SWIM; they DON’T WALK ON LAND ! So - Where DID Whales Come From? What would the earliest whales look like?

The Earliest MODERN WHALES… NOW Only go back to about 23 mya… the beginning of the MIOCENE… 5 mya MIOCENE 23 mya Great swimmers… but NO WALKING LEGS ! 65mya

HOWEVER ! from the EOCENE ! We DO have some whale-like fossils, with strange teeth, NOW 5 mya MIOCENE 23 mya from the EOCENE ! 65mya

But… Where’s the Eocene? NOW NOW Miocene: Earliest modern whales 23 mya 34 mya EOCENE 55 mya 4.5bya 65mya

OK! So, where shall we look for Eocene Fossils? 38 Mountains of Pakistan The Tethys Sea 55 India Moved North… …Squished into Asia…

Where shall we look? Pakistan Lots of exposed marine Eocene rocks in the Pakistan mountains

Let’s Hunt Whale Fossils… Work in pairs Open Your Eocene Timeline Remove whale strips from plastic bag Listen for descriptions and timing Place whale strip on timeline Wait for next “discovery”

Eocene Epoch Timeline

Early Whale Teeth in Dorudon ~ 36 mya 1936

Eocene Epoch Timeline Dorudon 36 mya (39-36 my) 1936

Early Whale Teeth… in a 4-legged mammal? a Mesonychid - called Pachyaena ~ 55 mya … with tiny hooves!

Eocene Epoch Timeline Dorudon 36 mya (39-36 my) 1936 Pachyaena 55 mya (58-34 mya) 1955

Early Whale Teeth …and hooves, too! In Pakistan… ~50 mya WITH LEGS ! Pakicetus - an early whale ~50 mya 1983 - Gingerich - Pakistan

Eocene Epoch Timeline Dorudon 36 mya (39-36 my) 1936 Pakicetus 50 mya (1983 - Pakistan) Pachyaena 55 mya (58-34 mya) 1955

Early whale teeth in… Basilosaurus ~37mya and LEGS, too… 1990 Gingerich - Egypt

Eocene Epoch Timeline Dorudon 36 mya (39-36 my) 1936 Basilosaurus 37 mya (39-36 mya) 1990 Pakicetus 50 mya (1983 - Pakistan) Pachyaena 55 mya (58-34 mya) 1955

Early Whale Teeth ~46 mya Rodhocetus - an early whale And tiny hooves, too ! ~46 mya early 1994 - Gingerich - Pakistan

Eocene Epoch Timeline Dorudon 36 mya (39-36 my) 1936 Basilosaurus 37 mya (39-36 mya) 1990 Rodhocetus 46 mya (early 1994 - Pakistan) Pakicetus 50 mya (1983 - Pakistan) Pachyaena 55 mya (58-34 mya) 1955

Eocene Epoch Timeline Transitional form? Predict What? (draw) Where? Dorudon 36 mya (39-36 my) 1936 Basilosaurus 37 mya (39-36 mya) 1990 Rodhocetus 46 mya (early 1994 - Pakistan) Transitional form? Predict What? (draw) Where? Pakicetus 50 mya (1983 - Pakistan) Pachyaena 55 mya (58-34 mya) 1955

Early Whale Teeth… in Pakistan With tiny hooves, too ! Ambulocetus - the “walking whale” ~48 mya late 1994 Thewissen

Eocene Epoch Timeline Dorudon 36 mya (39-36 my) 1936 Basilosaurus 37 mya (39-36 mya) 1990 Rodhocetus 46 mya (early 1994 - Pakistan) Ambulocetus 48 mya (late 1994 - Pakistan) Pakicetus 50 mya (1983 - Pakistan) Pachyaena 55 mya (58-34 mya) 1955

Ambulocetus Carl Buell

Whale Phylogeny, 1994 Hans Thewissen

But Mesonychids are EXTINCT! SO, Who are the Closest Living Relatives of Whales? Maybe Hooved Mammals?: = Ungulates: Two Orders: 33-38: Hooved animals and ANKLE evidence Perissodactyls (odd-toed) Artiodactyls (even-toed)

Perissodactyls Odd-Toed Ungulates Rhinos & Tapirs Horses & Zebras

Artiodactyls Even-Toed Ungulates

Leg Anatomy… Heel Bone Ankle Bone

Ungulate Foot Bones… FOSSIL HORSE FOSSIL PIG Heel Bone Ankle Bone

Whale Ankles? Compare ankle bones… Pig Pakicetus Mesonychid two small ridges Mesonychid Prim. Artiodactyl Prim.Perissodactyl Ankles Compared (with arrows showing…) one big ridge

Whale Phylogeny, 2001 Philip Gingerich Early whale ankles indicate close relationship with artiodactyls (even-toed ungulates) Mesonychid ankles indicate they are closer to perissodactyls (odd-toed ungulates)

But WHICH Artiodactyls? Will DNA Tell Us? 40-48: DNA analysis indicates hippos are the most closely related living animals to whales. Let’s Compare DNA…

DNA Analysis Compare segments of beta-casein gene

DNA Analysis Compare segments of beta-casein gene

DNA Differences

DNA Differences

DNA Differences Fewer than five differences… 2 porpoise & sperm whale 3 porpoise & right whale 3 sperm whale & right whale 3 sperm whale & hippo 3 porpoise & hippo 3 right whale & hippo 3 giraffe & deer 3 giraffe & cow 4 cow & deer

DNA Differences Seven differences… 7 pigs and peccaries DNA Differences Remaining species… Higher numbers - more distantly related

Phylogenetic Tree - WHALES Based on DNA Differences

Provisional Phylogeny - Cetartiodactyls

Whale Evolution Recap Fossil teeth link whales to the 4-legged mesonychids of the Paleo-Eocene Tiny hooves on mesonychids and early whale toes tie whales to the ungulates Ankle bones of early whales point to artiodactyl ungulates as the closest relatives of whales

Whale Evolution Recap DNA confirms the artiodactyl connection and points to hippos as the closest cousins of whales Consilience: these multiple independent lines of evidence strengthen, narrow and confirm the hypothesized close relationship between whales and artiodactyls

Whale’s Closest Cousin: Hippos

If possible, play a little humpback whale “music” here!

FAREWHALE!

Have a Whale of a Time! FINI