1 / 21

IV. Life History Evolution Trade-Offs Components of fitness? - probability of survival

Explore the intricate trade-offs between survival and reproduction in organisms. Understand how energy budgets impact growth and the strategies species employ to maximize fitness. Learn about the delicate balance between the number of offspring and their survival rates, and how environmental factors influence life history strategies. Dive into the fascinating dynamics of timing in life history evolution and the impact of human interaction on species' reproductive behaviors. Unveil the complexities of senescence and the evolution of post-reproductive periods in different species. Delve into the diverse life history strategies employed by organisms to adapt to changing environments.

nnoel
Download Presentation

IV. Life History Evolution Trade-Offs Components of fitness? - probability of survival

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. IV. Life History Evolution • Trade-Offs • Components of fitness? • - probability of survival • - number of offspring • - probability that offspring survive

  2. IV. Life History Evolution • Trade-Offs • 2. Relationships with Energy Budgets METABOLISM GROWTH SURVIVAL METABOLISM REPRODUCTION REPRODUCTION

  3. IV. Life History Evolution • Trade-Offs • 3. Trade-offs Between Survival and Reproduction Maximize probability of survival Maximize reproduction GROWTH METABOLISM GROWTH REPRODUCTION METABOLISM REPRODUCTION

  4. IV. Life History Evolution • Trade-Offs • 3. Trade-offs Between Survival and Reproduction Add 2 chicks. Fledge an additional 0.75 chicks, at a cost of 10% decrease in survivorship European Kestrels

  5. IV. Life History Evolution • Trade-Offs • 3. Trade-offs Between Survival and Reproduction Cox, R.M., and R. Calsbeek. 2010. Severe costs of reproduction persist in Anolis lizards despite the evolution of a single-egg clutch. Evolution 64: 1321-1330.

  6. IV. Life History Evolution • Trade-Offs • 3. Trade-offs Between Survival and Reproduction Having a second offspring increases reproductive success by 100%. Moving from 4 offspring to 5 only increases fitness by 25%, but the cost of that 5th offspring is the same as the cost of the second.

  7. IV. Life History Evolution • Trade-Offs • 3. Trade-offs Between Survival and Reproduction • - Suppose the probability of adult survival is low for other reasons? Can wait Can’t wait

  8. IV. Life History Evolution • Trade-Offs • 3. Trade-offs Between Survival and Reproduction • - Suppose the probability of adult survival is low for other reasons? Can vary within a species in different environments: Guppies

  9. IV. Life History Evolution • Trade-Offs • 4. Trade-offs Between # offspring and offspring survival METABOLISM REPRODUCTION REPRODUCTION METABOLISM A few large, high prob of survival Lots of small, low prob of survival

  10. IV. Life History Evolution • Trade-Offs • 4. Trade-offs Between # offspring and offspring survival Decrease size, decrease probability of survival

  11. IV. Life History Evolution • Trade-Offs • 4. Trade-offs Between # offspring and offspring survival – Lack Hypothesis Decrease size through decreased parental care, decrease survival Again, diminishing returns, then net cost

  12. IV. Life History Evolution • Trade-Offs • 4. Trade-offs Between # offspring and offspring survival – Lack Hypothesis Varies within a species under different environmental conditions: Guppies

  13. IV. Life History Evolution • Trade-Offs • Timing • 1. First Age of Reproduction • 2. Parity: How Often to Reproduce • - Semelparous vs. iteroparous Semelparity = once Iteroparity = iterative… many

  14. IV. Life History Evolution • Trade-Offs • Timing • 1. First Age of Reproduction • 2. Parity: How Often to Reproduce • - Semelparous vs. iteroparous Variable environment; “all in” when favorable may not get another chance Benign environment; no need to sacrifice future reproduction.

  15. III. Life History Evolution • Trade-Offs • Timing • 1. First Age of Reproduction • 2. Parity: How Often to Reproduce • 3. Senescence • - Why age? • - Accumulation of mutations • - Cost of DNA repair late in life vs. expending • that energy in reproduction earlier in life. Why do human have a long post-reproductive period? The ‘grandmother effect’ Lahdenpera et al., 2005. Nature. Finland, 1702–1823, (6,002 grandchildren born). Canada, 1850 to 1879 ,(100,074 grandchildren born)

  16. III. Life History Evolution • Trade-Offs • Timing • Life History Strategies

  17. III. Life History Evolution • Trade-Offs • Timing • Life History Strategies

  18. III. Life History Evolution • Trade-Offs • Timing • Life History Strategies • Effects of Humans Tree swallows breed 9 days earlier in North America; salamanders in Britain bred 7 weeks earlier! Correlates with mean temperature.

  19. III. Life History Evolution • Trade-Offs • Timing • Life History Strategies • Effects of Humans Flowerin gof 42 plants in Concord, MA, is an average of 7 days earlier than when recorded by Thoreau in 1852, and mean temp is 2.4oC higher (~ 4oF).

  20. III. Life History Evolution • Trade-Offs • Timing • Life History Strategies • Effects of Humans

  21. Selection for earlier age of maturity, too.

More Related