Evolution and Life History Traits in Biology: Lecture 16

Life history traits include an organism’s age at first reproduction, the duration and schedule of reproduction, the number and size of offspring produced, and life span.

Short life, many eggs; Reproduce once in a short life; Long life, fewer offspring; Continually reproduce over a long life.

Life history traits involve trade-offs, as there is a limited amount of energy to invest in survival, maintenance, and reproduction.

<p>Natural selection aims to maximize the number of offspring surviving to maturity.</p> Signup and view all the answers

<p>Data from opossums on Sapelo Island, GA, show that with no predators, island opossums live longer and have fewer offspring.</p> Signup and view all the answers

<p>A potential trade-off for living longer could be having fewer offspring.</p> Signup and view all the answers

<p>Life history strategies are subject to evolution, as they are influenced by environmental factors and reproductive success.</p> Signup and view all the answers

<p>Examples of life history traits include an organism’s age at first reproduction, number of offspring produced, and life span.</p> Signup and view all the answers

<p>Organisms may regulate the sex ratio of offspring to maximize fitness.</p> Signup and view all the answers

<p>Mothers produce females when in poor condition.</p> Signup and view all the answers

<p>Mothers produce males when in good condition.</p> Signup and view all the answers

<p>Organisms may cannibalize eggs or offspring for higher fitness and survival of the remaining offspring.</p> Signup and view all the answers

<p>Females may alter sex ratios of offspring to ultimately enhance fitness and survival in the offspring.</p> Signup and view all the answers

<p>Females of fig wasps and other Hymenoptera can alter sex ratios through haplodiploidy.</p> Signup and view all the answers

<p>Thrips, like fig wasps, are haplodiploid and females can adjust sex ratios using this genetic system.</p> Signup and view all the answers

<p>Organisms regulate the number of offspring to maximize fitness over their lifetime.</p> Signup and view all the answers

<p>Frequency-dependent selection</p> Signup and view all the answers

<p>The rare sex has more mating opportunities.</p> Signup and view all the answers

<p>Gene expression silenced by methylation by one parent.</p> Signup and view all the answers

<p>Both hybrids of horses and donkeys, but different species is the father.</p> Signup and view all the answers

<p>Heritable changes in gene expression, perhaps accrued during the individual’s lifetime due to behavior and environment.</p> Signup and view all the answers

<p>High predation leads to guppies having more offspring, lower weight, and younger reproductive age.</p> Signup and view all the answers

<p>There is a trade-off between reproduction and growth/survival visible during the lifetime of an individual.</p> Signup and view all the answers

<p>Females are more likely than males to provide parental care.</p> Signup and view all the answers

<p>Jacanas.</p> Signup and view all the answers

<p>OSR is the ratio between sexually receptive males and females in a population.</p> Signup and view all the answers

<p>Female-biased.</p> Signup and view all the answers

<p>Mate choice is important for male pipefishes.</p> Signup and view all the answers

<p>Male pipefishes vary in the number of mates compared to females.</p> Signup and view all the answers

<p>Some species switch sex in a “Trivers-Willard-predicted” manner</p> Signup and view all the answers

<p>Cost-benefit analysis</p> Signup and view all the answers

<p>Start as females and switch to males when large</p> Signup and view all the answers

<p>Some species of booklice</p> Signup and view all the answers

<p>Pseudo-arrhenotoky</p> Signup and view all the answers

<p>Males inherit but do not pass on their father’s genetic material</p> Signup and view all the answers

<p>To maximize reproductive success and genetic diversity</p> Signup and view all the answers

<p>Daughters can help raise more offspring</p> Signup and view all the answers