BIS2C: Lecture 33: Vertebrates

1. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Lecture 33:
Deuterostomes III:
Chordates II
BIS 002C
Biodiversity & the Tree of Life
Spring 2016
Prof. Jonathan Eisen
1

2. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Where we are going and where we have been…
2
•Previous lecture:
•32: Deuterostomes II: Chordates
•Current Lecture:
•33: Deuterostomes III: Chordates II
•Next Lecture:
•34: Fungi

3. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
SmartSite issues?
How are the problems with SmartSite
affecting you?
A. Causing me lots of trouble
B. Causing me some trouble
C. Causing me no trouble
D. Good riddance
E. Both A and D
3

4. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
BIS2C Final Exam Section B
4
Date & Time: Saturday, June 4, 1:00 PM – 3:00
PM
Please arrive early and bring:
1. Photo ID
2. Pen
3. #2 pencil
LAST NAMES EXAM LOCATION
A - J
1100 SOCIAL
SCIENCES
K - R 1003 GEIDT
S - Z 176 Everson

5. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Lab Practical: May 31-June 2
Do NOT enter until instructed by your TA
**Please show up 10 minutes in advance of your exam**
The start time of your exam depends on where you usually attend lab. Most of you will be starting at
your regular lab time, but see below for the ‘halfway’ start times.
Regular lab location Exam is in Exam starts at
3079 SLB 3079 SLB usual start time
3085 SLB 3085 SLB usual start time
3088 SLB 3079 SLB halfway through period
3090 SLB 3085 SLB halfway through period
Regardless of when your exam will begin, do not be late as there is no way for you to make up the
questions that you missed.
The times listed below are ONLY for the 3088 & 3090 SLB students with halfway start times:
Usual lab time Lab practical starts at
7:30am 8:55am
9:00am 10:25am
11:00am 12:25pm
1:10pm 2:35pm
2:30pm 3:55pm
5:10pm 6:35pm
6:10pm 7:35pm
5

6. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Eisen Office Hours
Friday 3:00 - 5:00
6

7. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Other Things
• Study Guides will be posted over the next
few days
• Final is 2/3 about animals, 1/3 about rest of
course
• Review sessions to be scheduled
7

8. Vertebrate Origins
!8Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Ciliated
larvae
AmbulacrariansChordates
Common
ancestor
(bilaterally
symmetrical,
pharyngeal
slits
present)
Echinoderms
Hemichordates
Lancelets
Tunicates
Vertebrates
Radial symmetry as adults,
calcified internal plates,
loss of pharyngeal slits
Vertebral column, anterior skull,
large brain, ventral heart
Notochord,
dorsal hollow
nerve cord,
post-anal tail
Focus on Vertebrates

9. Phylogeny of the Living Vertebrates
!9Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Amniotes
Lampreys
Hagfishes
Lungfishes
Amphibians
Chondrichthyans
Ray-finned fishes
Coelacanths

10. Focus on Two Key Things
!10Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Amniotes
Lampreys
Hagfishes
Lungfishes
Amphibians
Chondrichthyans
Ray-finned fishes
Coelacanths
Getting to Humans

11. In-Text Art, Ch. 33, p. 693 (1)

12. In-Text Art, Ch. 33, p. 707
!12Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Amniote
ancestor
Crocodilians
REPTILES
Tuataras
Squamates
Turtles
Theropods,
including birds
Mammals
MAMMALS

13. In-Text Art, Ch. 33, p. 696
!13Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Reptiles
Eutherians
Marsupials
Prototherians

14. Figure 33.28 Major Groups of Eutherians Diversified as the Continents Drifted Apart
!14Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Million years ago
Africa
Africa
Africa
Africa
Africa
South
America
SE Asia
SE Asia
Proto-Europe
Proto-Europe
Proto-Europe
Laurasia
Laurasia
Laurasia
Laurasia
Laurasia
Laurasia
Madagascar, Africa
Africa
Africa
Africa, Asia
Africa, Middle East
North, South America
SE Asia
SE Asia
Tropics of Africa,
Americas, Asia
North America,
Eurasia
Worldwide
Worldwide except
Australasia
Worldwide except
Australasia
Africa, southern Asia
Worldwide except
Australasia
Worldwide except
Australasia
Worldwide
Current native
distribution
Earliest
FossilsGroup
African
insectivores
Long-nosed
insectivores
Aardvarks
Elephants
Hyraxes
Armadillos
Colugos
(“flying lemurs”)
Tree shrews
Primates
Rabbits
and pikas
Rodents
Shrews, moles,
and relatives
Bats
Pangolins
Odd-toed hoofed
mammals
Even-toed hoofed
mammals

15. Figure 33.30 Phylogeny of the Primates
!15Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Pleistocene
Gibbons
Orangutans
African apes
and humans
Miocene
Oligocene
Eocene
Paleocene
Pliocene
Lemurs
Prosimians
Mid-to-late
Cretaceous
Anthropoids
Lorises
Tarsiers
New World
monkeys
Old World
monkeys

16. Figure 33.34 A Phylogenetic Tree of Hominins
!16Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Ardipithecine
ancestors
Paranthropus boisei
Homo sapiens
(now worldwide)
Million years ago
Australopithecus
afarensis (Lucy)
Australopithecus
africanus
Paranthropus
aethiopicus Paranthropus robustus
Homo floresiensis
(extinct 17,000 years ago)
Homo erectus
(extinct 250,000 years ago)
Homo ergaster
Homo neanderthalensis
(extinct 28,000 years ago)
Homo habilis
Africa only
Expansion out of Africa

17. Vertebrate Evolution
!17Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
How Do People Figure This All Out?

18. Get Samples of Diverse Organisms
!18Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016

19. Gather Lots of Data
!19Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016

20. Including Fossils
!20Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016

21. Infer a Phylogenetic Tree
!21Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016

22. Phylogeny of the Living Vertebrates
!22Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Amniotes
Lampreys
Hagfishes
Lungfishes
Amphibians
Chondrichthyans
Ray-finned fishes
Coelacanths

23. Major Innovations in Vertebrate Evolution
!23Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Bony skeleton, swim
bladder/lung
Jawless
fishes
Lobe-limbed
vertebrates
Amniotes
Gnatho-
stomes
(”jaw
mouths”)
Terrestrial limbs
and digits
Lobe fins
Lampreys
Internal nares
Vertebrae
Jaws, teeth,
paired fins
Hagfishes
Amniote
egg
Lungfishes
Amphibians
Chondrichthyans
Ray-finned fishes
Coelacanths
How Did People Figure This All Out?

24. Comparative Biology
!24Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Post
anal tail
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Vertebrae
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Jaws
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Lobe
Fins/
Limbs
No
No
No
No
Yes
Yes
Yes
Yes
Terrestrial
Limbs
No
No
No
No
No
No
Yes
Yes
Other
Amniotes
Lampreys
Hagfishes
Lungfishes
Amphibians
Chondrichthyans
Ray-finned fishes
Coelacanths

25. Overlay Onto Tree
!25Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Post
anal tail
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Vertebrae
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Jaws
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Lobe
Fins/
Limbs
No
No
No
No
Yes
Yes
Yes
Yes
Terrestrial
Limbs
No
No
No
No
No
No
Yes
Yes
Amniotes
Lampreys
Hagfishes
Lungfishes
Amphibians
Chondrichthyans
Ray-finned fishes
Coelacanths

26. Infer Likely Ancestral and Derived Traitss
!26Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Post
anal tail
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Vertebrae
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Jaws
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Lobe
Fins/
Limbs
No
No
No
No
Yes
Yes
Yes
Yes
Terrestrial
Limbs
No
No
No
No
No
No
Yes
Yes
Amniotes
Lampreys
Hagfishes
Lungfishes
Amphibians
Chondrichthyans
Ray-finned fishes
Coelacanths

27. Major Innovations in Vertebrate Evolution
!27Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Bony skeleton, swim
bladder/lung
Jawless
fishes
Lobe-limbed
vertebrates
Amniotes
Gnatho-
stomes
(”jaw
mouths”)
Terrestrial limbs
and digits
Lobe fins
Lampreys
Internal nares
Vertebrae
Jaws, teeth,
paired fins
Hagfishes
Amniote
egg
Lungfishes
Amphibians
Chondrichthyans
Ray-finned fishes
Coelacanths

28. The Vertebrate Body Plan (not in all …)
!28Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Anterior skull
enclosing a large brain
A jointed, dorsal
vertebral column
replaces the
notochord during early
development.
Internal Organs
suspended in a
coelom
Well-developed
circulatory
system driven by
a ventral heart
Rigid Internal Skeleton

29. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Vertebrate Evolution
• The structural features can support large,
active animals.
• Internal skeleton supports an extensive
muscular system that gets oxygen from the
circulatory system and is controlled by the
nervous system.
• These features allowed vertebrates to
diversify widely.
29

30. Photo 33.105 Family Balaenopteridae: fin whale (Balaenoptera physalus); Baja California, Mexico.
!30Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016

31. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Sister group for all other vertebrates
31
Hagfish

32. Photo 33.18 Pacific hagfish (Eptatretus stouti).

33. You’ve Been Slimed

34. !34Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Anterior skull
enclosing a large brain
A jointed, dorsal
vertebral column
replaces the
notochord during early
development.
Internal Organs
suspended in a
coelom
Rigid Internal Skeleton
Well-developed
circulatory
system driven by
a ventral heart
The Vertebrate Body Plan

35. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 35
Lampreys

36. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Lampreys
36
• Complete cranium and cartilaginous vertebrae.
• Complete metamorphosis from filter-feeding larvae
(ammocoetes), which are similar to lancelets.
• No bone, no jaws, but cartilaginous vertebrae are present
• Sucker- like mouth with rasping teeth
• Many species are ectoparasites of fish

37. Photo 33.17 Anadromous lamprey (Petromyzon marinus); Rhode Island.

38. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 38
Vertebrae Evolution
Lampreys have cartilaginous vertebrae so infer that
vertebrae evolved here.

39. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Gnathostomes - Jaw Mouths
39
• Jaws evolved from gill arches late in the Ordovician.
• Name from Greek gnathos (jaw) & stoma (mouth)

40. Figure 33.12 Jaws and Teeth Increased Feeding Efficiency
!40Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016

41. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
33.3 What New Features Evolved in the Chordates?
• Jaws improved feeding efficiency and prey
capture.
• Jawed fishes diversified rapidly and
became dominant.
• Teeth made feeding even more efficient.
Chewing aids chemical digestion and
improves extraction of nutrients from food.
41

42. Sling Jawed Wrasse
• Previous lecture:
! Bis2B
!
!42Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016

43. Chondrichthyans (sharks, rays, skates, chimaeras):
!43Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
• Skeletons of cartilage
• Flexible, leathery skin
• Sharks swim using lateral undulations of the body.
• Skates and rays swim by flapping enlarged pectoral fins.

44. Chondrichthyans
!44Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016

45. Megalodon
!45Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
• One of the largest vertebrate predators, 50-60ft
• Largest known tooth ~8 inches
• Extinct about 1.5 million years ago
• Likely fed on whales and other large prey

46. Great White Shark
!46Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
• Up to 20ft and 5,000 lbs; apex predator
• Feeds on marine mammals, fish, and seabirds
• Likely a close relative of Megalodon
• Global distribution; migratory behavior (12,000 miles/ 9 months)
Farallon Islands

47. Bones
!47Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
• One lineage of gnathostomes gave rise to the bony vertebrates with
internal skeletons of calcified, rigid bone.
• Some early bony fishes had gas-filled sacs that supplemented the gills
in gas exchange.

48. Ray Finned Fishes
!48Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
• In ray-finned fishes, the sacs developed into swim bladders, organs of
buoyancy.
• Allows fish to maintain position at specific depths.

49. !49Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016

50. Ray Finned Fish- Actinopterygii
• Largest group of bony fish; 30,000 described species
• Both freshwater and marine, diverse feeding habits
!50Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016

51. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Big Change Coming - Invasion of Land
51
• What features contributed to the invasion of and diversification on
land?

52. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Where Else Have We Discussed Invasion of Land
Which of the following is NOT considered to
be a critical adaptation for the invasion of the
land by eukaryotes?
A. Pigments
B. Mutualistic associations with fungi
C. Hardened cuticle
D. Waxy cuticle
E. Jaws
52

53. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Where Else Have We Discussed Invasion of Land
Which of the following is NOT considered to
be a critical adaptation for the invasion of the
land by eukaryotes?
A. Pigments
B. Mutualistic associations with fungi
C. Hardened cuticle
D. Waxy cuticle
E. Jaws
53

54. Land Plants …
!54Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Plantae
Retention of egg in the parental organism;
plasmodesmata; similarities in mitosis and
cytokinesis
Chloroplasts
primary endo-
symbiosis)
Chlorophyll b;
starch storage
Protected embryo; cuticle;
multicellular sporophyte;
gametangia; thick-walled spores
Branched apical growth
Land plants
(embryophytes)
Stoneworts
(“green algae”)
Coleochaetophytes
(“green algae”)
Other “green algae”
Chlorophytes (most “green algae”)
Red algae
Glaucophytes
Green plants
Streptophytes

55. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Arthropods
55

56. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Arthropod Key Feature: Exoskeleton
• Exoskeleton is a thickened
cuticle
• Restricts movement and gas
exchange
• Requires ecdysis
• Muscles attached to inside
• Provides support for walking
on land, prevents drying,
and provides some
protection from predators.
• Aquatic arthropods were
thus excellent candidates to
invade land.
56

57. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Big Change Coming - Invasion of Land
57
• What features contributed to the invasion of and diversification on
land?

58. Lungs / Swim Bladder
!58Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
• Lung-like sacs likely evolved much before vertebrates invaded the land
• Supplemented gills when in shallow water / water low in O2
• Evolved into swim bladders in many ray-finned fish

59. Lobe Fins
!59Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
• Bony fish that lack bony spines (rays) as part of their fins
• The more muscular fins are joined to the body by a single large bone
• Changes in the structure of fins allowed some fish to support
themselves in shallow water and later move onto land.

60. Coelacanths
!60Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016

61. Coelocanths
• Thought to have become extinct 65 mya, but living ones
were found off South Africa in 1938.
• They have a cartilaginous skeleton that is a derived feature.
!61
Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016

62. More Fully Developed Lungs
!62Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
• Elaboration on the lung like sacs into lungs

63. More Fully Developed Lungs
!63Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016

64. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 64

65. Tetrapods
!65Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
• Limbs capable of movement on land evolved from the short, muscular
fins of aquatic ancestors.
• The four resulting limbs give the tetrapods their name.

68. Fossils Also Important
!68Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
http://www.hhmi.org/biointeractive/great-transitions-interactive

69. Tetrapod Limbs Are Modified Fins
!69Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016

70. Amphibians
!70Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016

71. Amphibians
!71Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
~7,000 species
Confined to moist habitats: lose water easily
through the skin, and eggs dry out if exposed to
air.

72. Amniotes
!72Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
Amniotes have several features that contribute to their success on dry land.