Longevity

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Longevity Lecture 8 Thursday, November 1, 2001

• Life Span
• Conceptual issues
• Evolution of longevity in flowers
• Life span in animals
• Co-evolution of longevity and sociality

Start with brief review of elderly in nature
lecture
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Mean71 Range43-94 A-range 78 B-range
63-77 C-range 50-62
Statistics of 1st Midterm HDE/ENT 117
Score ()
Rank of Test-takers
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Instructor Prof. James R. Carey Office 67
Briggs Hall Email jrcarey_at_ucdavis.edu Phone
752-6217 Office Hours Monday 10-11a
Wk Day Date Themes Topic(s) 1 1 Tue Oct.
2 Overview of concepts and course 2 Thur Oct. 4
Life Table Life tables I basic concepts and
techniques 2 2 Tue Oct. 9 Life tables II sex
differences cause of death 3 Thur Oct.
11 Mortality Mortality models and
concepts 3 4 Tue Oct. 16 Model systems Fruit
fly/insect models 5 Thu Oct. 18 Aging Senescence
origins theories of aging 4 6 Tue Oct.
23 Synopsis and overview of aging 7 Thu Oct.
25 1st Midterm 5 8 Tue Oct. 30 Natural- Populatio
n biology of the elderly 9 Thu Nov.
1 history Record life spans primate
patterns 6 10 Tue Nov. 6 Evolution of
longevity 11 Thu Nov. 8 Genetics of longevity
7 12 Tue Nov. 13 Biodemo- General biodemographic
principles 13 Thu Nov. 15 graphy Theory of
longevity extension 8 14 Tue Nov. 20 2nd
Midterm 15 Thu Nov. 22 THANKSGIVING HOLIDAY
9 16 Tue Nov. 27 Human Mortality trends in
oldest-old 17 Thu Nov. 29 longevity Centenarians
and supercentenarians 10 18 Tue Dec.
4 Successful aging longevity determinants 19 Th
u Dec. 6 The future of human life span
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Life-history Traits Associated with Extended
Longevity in Social Animals

• Long gestation or developmental period
• Small number of offspring per pregnancy
• Long interbirth intervals
• Long period of offspring development
• Intense parenting/brood care
• Strong social bonds
• Protracted learning period
• Home base, nest or territory as locus
• Monogamy/pair bonding
• Enhanced sibling relations

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The Life Span Concept Fundamental Considerations
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Life Span Conceptual Issues
1. Life duration (broader concept than life span)
2. Individual (discrete functional entity)
3. Genesis (conception fetal stage birth
adulthood)
4. State of existence (normal arrested
metabolism)
5. Time of existence (normal plus period of
arrest)
6. Extinction (death fission fusion)
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The Life Span Concept Examples Where the Lines
are Blurred
1. Amoeba forming macro organism
2. Hydra replacing all of cells every 10 days
3. Flatworm split into separate parts
4. Embryos dividing to form clones (e.g.
identical twins)
5. Chimeras formed when embryos fuse
MAIN POINT issues concerning level of
individualismbirth and death processes, and the
disappearance oforiginal individuals invalidate
the classic definition of life spanfor many
organisms and/or for certain situations with
humans
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Quantum Nature of Death
Coma Breath stoppage Heart stoppage
Brain death Cessation of growth/metabolism
Tissue degradation Loss of DNA
integrity
How can a person be deader than dead?
Death of immediate family members, extended
familymembers, whole clan, whole race, all of
humans, all of life.
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Related Concepts

• Mortaldestined to die
• Immortalliving forever
• Eternallife after death
• Infinityendlessness
• Determinatefixed growth or age
• Indeterminateopen-ended growth or life span

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Life Span and Age

• Two Types of Ages
• Chronological
• Physiological

• Two Types of Chronological Ages
• Postnatal agefrom birth
• Total agefrom conception

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The Life Span of Flowers
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Evolution of Flowers
1. Earliest seed plants were gymnosperms (e.g.
conifers)that use wind pollination (i.e.
shotgun approach)
2. Reproductive efficiency increased if could
find way to haveanimal transfer pollen from male
to female plant(i.e. rifle approach)
3. Stage was set 150 mya when beetles began
feeding onprotein-rich pollen from male plants
and sugar-rich cones of female plants
4. Two conditions necessary i)enough pollen and
sugar avail-able so that makes worthwhile for
insects to visit andii)the location and
richness of these food sourcesmust be advertised
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Length of Time Flower Stays Open
1. The probability and number of times it will be
visited
2. The total number of flowers open at any one
time on a plant

• The flowers must be physiologically maintained,
  and long-lived flowers may represent a major
  drain on the water and energy balance of the
  plant

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Factors Determining Flower Longevity
1. Habitat (e.g. temperate vs tropical forest vs
plains)
2. Within and among plant families (e.g.
Rosaseae Geraniaceae)
3. Breeding system (inbreeding outbreeding)
4. Male and female flowers (pistellate vs
staminate)
5. Phenological patterns (i.e. big bang
cornucopia steady state)
6. Pollinator class (e.g. bees flies beetles
hummingbirds)
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Variation in Flower Longevity Due To
1. Genetic factors based on level of outcrossing
2. Physiological factors based on need to reduce
water loss andmetabolic cost
3. Strategic factors based on abundance of
pollinators
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Animal Life Spans
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Vertebrate Life Spans (n2570)
1 5 10 15
Elephants (80) Whale (96) Horse (62) Humans (122)
Whales/dolphins
Odd-toed ungulates
Seals
Primates
Carnivores
Mammals
Bats
Marsupials
Rabbits
Rodents
Insectivores
Ostriches
1 5 10 15 20
Parrots (73) Hornbill (70)
Albatross
Seabirds
Birds
Pelicans
Waterfowl
Order/ Family
Falcons
Gulls
Owls
Pigeons
Perching birds
Fowl
Herps
Swifts
Crocodiles
1 5
Tortoise (153) Tuatara (77)
Frogs
Lizards
Sturgeons (152) Rock bass (75) Whale shark
(70)
1 5 10
Eels
Rockfish
Carp
Salmon
Fish
Shad
Seahorses
0
10
20
30
40
50
60
60
Life Span (years)
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Relationship of Flight Capability and Longevity
1. Birdsnest replaces womb from mammals
nest failure high
2. Batsflight, particularly quick darting
flight for foraging for insects in the air, is
incompatible with gestating multiple fetuses
for large litters most bats have single young
3. Thus need reproductive redundancy in time.
For birds is due to high nest failure rate
for bats because cannot gestate multiple
young simultaneously
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Life Spans of Social Insects
Months
Years
Decades
Weeks
paper wasp workers hornet queens
Wasps
Bees
bumble bees stingless bees honeybee queens
ant workers
ant queens
Ants
termite workers
termite queens
Termites
Workers
Queens
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Co-evolution of Longevity and Sociality
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Evolution of Eusociality in Wasps
host
wasp egg or larva
(f)
(a)
(e)
(b)
(c)
(d)
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Evolution of Sociality and Extended Longevity in
Wasps

• I. Emergence of Nest as Locus
• Prey paralyzed
• Prey stung, dragged to hole
• Prey placed in nest
• Nest made first, several prey added
• Same as 4 but more prey added after egg laid
• II. Emergence of Parental Care
• 6. Same as 5 except progressive provisioning
• 7. Egg laid in empty cell
• 8. Food macerated and fed directly to larvae
• 9. Life of female prolonged to overlap
  offspring
• 10. Trophallaxis female feed offspring other
  than their own
• III. Emergence of Queen Concept
• 11. Egg laying by single female
• 12. Worker caste defined
• 13. Worker caste morphologically distinct

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Strategic Factors Favoring the Evolution of
Extended Longevity
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Term Papers