1 / 9

Evolution of Aging

Evolution of Aging. Katy Nicholson and Coco Shea. Why do organisms age?. Decline in individual’s fertility and probability of survival. Lose ability to completely repair mutations in cells and tissue (lack of energy). Definition of Aging (Senescence).

pauling
Download Presentation

Evolution of Aging

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. Evolution of Aging Katy Nicholson and Coco Shea

  2. Why do organisms age?

  3. Decline in individual’s fertility and probability • of survival • Lose ability to completely repair mutations in • cells and tissue (lack of energy) Definition of Aging (Senescence) • Decline in individual’s fertility and probability • of survival • Lose ability to completely repair mutations in • cells and tissue (lack of energy) • Decline in individual’s fertility and probability • of survival • Decline in individual’s fertility and probability • of survival

  4. Populations lack the genetic variation necessary to respond to selection against aging • Telomeres are shortened every time a cell divides (Harley et al. 1990) Rate of Living Theory • Populations lack the genetic variation necessary to respond to selection against aging • Populations lack the genetic variation necessary to respond to selection against aging • Telomeres are shortened every time a cell divides (Harley et al. 1990)

  5. Accumulation of deleterious mutations after reproductive age • Accumulation of deleterious mutations after reproductive age • Less selective pressure on deleterious mutations after reproductive age • Less selective pressure on deleterious mutations after reproductive age • Neutral alleles can drift to fixation Evolutionary Theory of Aging • Accumulation of deleterious mutations after reproductive age • Accumulation of deleterious mutations after reproductive age • Less selective pressure on deleterious mutations after reproductive age • Neutral alleles can drift to fixation

  6. Evolution of Shorter Life Span: Accumulation of Deleterious Mutations Fig. 12.11Houseflies - Reed and Bryant (2000)

  7. Reproduce Early or Reproduce Longer? • Antagonistic Pleiotropy Hypothesis – Mutation • allocates energy to early reproduction or late death Energy Trade-Offs • Reproduce Early or Reproduce Longer? • Reproduce Early or Reproduce Longer? • Antagonistic Pleiotropy Hypothesis – Mutation • allocates energy to early reproduction or late death

  8. Antagonistic Pleiotropy Hypothesis • eg. Nematode: Caenorhabditis elgans (Walker et al. 2000) • eg. Nematode: Caenorhabditis elgans (Walker et al. 2000) Fig. 12.12

  9. Aging is accumulation of deleterious • mutations • Allocate energy to reproducing early or to • repairing cells later Conclusion • Aging is accumulation of deleterious • mutations • Aging is accumulation of deleterious • mutations • Allocate energy to reproducing early or to • repairing cells later

More Related