New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here

Life Histories and Aging

by: Jesse McDonald

Life Histories and Aging Biology 286

Marketplace > Purdue University > Biology > Biology 286 > Life Histories and Aging
Jesse McDonald

Preview These Notes for FREE

Get a free preview of these Notes, just enter your email below.

Unlock Preview
Unlock Preview

Preview these materials now for free

Why put in your email? Get access to more of this material and other relevant free materials for your school

View Preview

About this Document

Covers some properties of aging and reproductoin
Introduction to Ecology and Evolution
Dr. Josh Springer
Class Notes
Ecology, aging, reproduction, Biology
25 ?




Popular in Introduction to Ecology and Evolution

Popular in Biology

This 3 page Class Notes was uploaded by Jesse McDonald on Sunday February 14, 2016. The Class Notes belongs to Biology 286 at Purdue University taught by Dr. Josh Springer in Spring 2016. Since its upload, it has received 21 views. For similar materials see Introduction to Ecology and Evolution in Biology at Purdue University.


Reviews for Life Histories and Aging


Report this Material


What is Karma?


Karma is the currency of StudySoup.

You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 02/14/16
Aging and Life Histories    Life is energy­intensive.     Two Hypotheses for Aging:  1. Rate of living hypothesis:  a. aging is caused by an accumulation of cell damage  i. Cell and tissue damage are caused by metabolism  ii. Selection has maximized organisms’ abilities to resist and repair damage  2. Evolutionary Hypothesis  a. Aging is caused by failure to repair damage in exchange for enhanced  reproductive success.  i. Repair damage is caused by:  1. Deleterious mutations   2. Trade­offs in repair vs. reproduction   b. Antagonistic pleiotropy ­​when one gene controls for more than one trait where at  least one of these traits is beneficial to the organism's fitness and at least one is  detrimental to the organism's fitness.    Rate of Living Hypothesis:  1. Cell and tissue damage are caused by metabolism  ● Extent of aging will correlate with metabolic rate.  ○ Organisms with a slower metabolic rate will age slower  ○ Organisms with a faster metabolic rate will age faster  2. Selection has maximized organisms’ abilities to resist and repair damage  ● Artificial selection should be able to extend longevity   ● Experiment: select for late reproduction by gathering eggs from old adults  ● Result: average lifespan increases from 35 to 60 days    ● Telomeres and Telomerase:  ○ Telomeres shorten with age  ○ Telomerase can restore shortened telomeres  ○ In humans, telomerase is expressed only in select cells types.   ○ The relationship between telomere length and longevity is not straightforward.    Evolutionary Hypothesis:  1. Aging is caused by a failure to repair damage in exchange for enhanced reproductive  success.   ● Mutation accumulation ­ by the time these accumulated mutations cause a  problem, the organism has already reproduced, passing on the mutations.  ○ There is insufficient selective pressure to weed out a mutation/allele that  causes late­in­life problems.   ○ Senescence ­ aging; deterioration of bodily processes with age   2. Antagonistic pleiotropy ­ mutations that give fitness benefits early in life but fitness costs  late in life are, on balance, evolutionarily advantageous.   ● Antagonistic = in opposition  ● Pleiotropy = a gene that influences more than one trait  ● Antagonistic pleiotropy ­ the allele confers both a benefit and a cost    Ecological Mortality Affects the Evolution of aging;  ● Ecological mortality = mortality due to predation, disease, accidents; mortality due to  factors outside of the organism  ● The evolutionary mechanisms that lead to senescence will be less effective in  populations with lower ecological mortality.   ○ Prediction: populations with lower ecological mortality will evolve delayed  senescence.  ● 1st year mortality is usually very high!  ● The 2 phenomena will be less effective in populations with lower ecological mortality  rates:  1. Late­acting mutations ­ organisms that live longer will live long enough to  experience the deleterious effects from the late­acting mutations, so selection  can act on these mutations.   2. Antagonistic pleiotropy ­ organisms live longer so they will live long enough to  experience the early­in­life benefits, AND the late­in­life costs. So selection acts  against mutations/alleles with late­in­life costs, and favors mutations/alleles  withOUT late­in­life costs.     Offspring Production:  ● Evolution balances investment in a number of offspring.  ● Reproduction is a cost but the benefit is passing on one’s genes.   ● The smaller the clutch size, the larger the proportion of surviving offspring.    Offspring Size:  ● A finite amount of energy can be invested in reproduction.  ● Offspring need to be large enough to survive but not so large as to [further] diminish  parental fitness.   ● There are trade­offs between size and number of offspring.  ● An individual offspring must reach a certain size to survive.  ● Increases in parental fitness gained via reproduction depend on the number of surviving  offspring.     Male and Female have conflicts of interest:  ● Mothers has an equal stake in each offspring.  ● An individual father has a stake ​nly his ow​offspring.   ● Social monogamy can be advantageous ­ these conflicts are minimized.   ○ Conflicts are minimized because both parents are equally invested in all offspring  ○ There are 2 hypotheses for the evolution of social monogamy in mammals:  ■ Male protection  ■ Paternal care and minimizing male infanticide     The life histories we observe are the natural product of many tradeoffs that maximize lifetime  reproductive success.  


Buy Material

Are you sure you want to buy this material for

25 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

Why people love StudySoup

Steve Martinelli UC Los Angeles

"There's no way I would have passed my Organic Chemistry class this semester without the notes and study guides I got from StudySoup."

Allison Fischer University of Alabama

"I signed up to be an Elite Notetaker with 2 of my sorority sisters this semester. We just posted our notes weekly and were each making over $600 per month. I LOVE StudySoup!"

Steve Martinelli UC Los Angeles

"There's no way I would have passed my Organic Chemistry class this semester without the notes and study guides I got from StudySoup."

Parker Thompson 500 Startups

"It's a great way for students to improve their educational experience and it seemed like a product that everybody wants, so all the people participating are winning."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.