Final Exam Flashcards
(37 cards)
What is life history?
The pattern of investment an organisms makes in growth and reproduction.
Life history traits include…
-age of first reproduction
-number of offspring produced
-size of offspring produced
-life span
What determines an organisms fitness?
The number of offspring it produces-and the number that survives to maturity, over the organisms ENTIRE lifetime.
Sexual selection is much weaker in populations that,
In species where both the male and female cooperate in caring for young. The OSR would be much less male biased because males spend the same amount of time with young as the females do, so they aren’t going to recycle any faster than females do.
Male-biased OSR results in what?
Strong sexual selection on males
Operational Sex Ratio (OSR):
Ratio of male to female individuals who are available to reproduce at any given time.
Trade-offs between reproduction and survival/growth arise when,
investment in one trait results in lower investment of another trait
Why are females more likely to provide parental care?
Males have less investment, males have uncertain paternity,
How could an organism regulate the number of offspring to maximize fitness?
miscarriage and cannibalism
Why are sex ratios often balanced?
Bc of frequency-dependent selection. Production of each sex is favored when rare and rare sex has more mating opportunities
Trivers-Willard Hypothesis
Predicts greater investment in male offspring by parents when conditions are good and greater investment in female offspring by parents when conditions are poor
Parental Conflict
occurs when parents have an evolutionary conflict of interest over the optimal strategy for parental care
What’s beneficial to mom is often…
not most beneficial for offspring
Parent-offspring conflict
Occurs when parents benefit from withholding parental care or resources from some offspring (for example, a current brood) and invest in other offspring (for example, a later brood). Conflict arises because the deprived offspring would benefit more if they received the withheld care or resources.
Offspring-offspring conflict
(sibling rivalry) occurs when siblings compete for parental care or limited resources.
Parent-of-origin effect
describes an effect on the phenotype of an offspring caused by an allele inherited from a particular parent.
Genomic Imprinting
occurs when genes inherited from one or the other parent are silenced due to methylation. Imprinting can result in offspring who express either the maternal or paternal copy of the gene, but not both.
Senescence
refers to the deterioration in the biological functions of an organism as it ages
Mother Hypothesis
risk of reproduction at older age selects for reduced fertility (investment in current offspring)
Grandmother Hypothesis
loss of fertility associated with shift in investment to grandchildren
Hominids
members of the clade that includes humans as well as all species more closely related to humans than chimpanzees. Humans are the only surviving member of the hominin clade.
Homo Naledi
Discovered in 2013 in a cave called Rising Star. Had legs adapted for upright standing and toes and arches that allowed it to walk in a humanlike way. However, had a tiny brain and fingers adapted for climbing trees. Determined to be 236,000 and 335,000 years ago. Homo sapiens, evolved around then, so we could have lived side by side with them.
Why did Linnaeus put humans in the order primates?
Because humans shared a number of anatomical similarities to primates, including their forward facing eyes and thumbs for gripping things.
The primate clade originated at the end of what period?
Cretaceous
