Evolution, 4th Edition

How To BE FiT 279 Fitness in age-structured populations In Chapter 3 we defined fitness for the simple case in which individuals ...

280 CHAPTER 11 patches before becoming extinct. This lifestyle favors the evolution of early repro- duction, so many weeds have ...

How To BE FiT 281 functions reduce fitness less, the later in life they exert these effects. That is, selec- tion against these ...

282 CHAPTER 11 population, causing the population to evolve a higher rate of increase. But this potential for population growth ...

How To BE FiT 283 year. But many other species, such as bristlecone pines and tortoises, and humans for that matter, do not fit ...

284 CHAPTER 11 guppies in Trinidad [6, 48]. In some streams, the cichlid fish Crenicichla preys heavily on guppies. In other str ...

How To BE FiT 285 arrive, they shut down immune defenses and other physiological functions, and expend all their energy in a fre ...

286 CHAPTER 11 Number of offspring All else being equal, a genotype with higher fecundity has higher fitness than one with lower ...

How To BE FiT 287 obtain enough energy to develop more seeds. A female slipper shell (Crepidula for- nicata) carries a stack of ...

288 CHAPTER 11 Specialists and Generalists As noted in the previous section, understanding the evolution of life history varia- ...

How To BE FiT 289 species succumb to unfavorable conditions or to a limited sup- ply of a resource; this was what inspired Darwi ...

290 CHAPTER 11 correlated [17, 23]. But a population could nevertheless evolve to be specialized, for several related reasons. T ...

How To BE FiT 291 individuals that develop on the abundant plant but not of individu- als that develop on the rare plant (FIGURE ...

SUMMARY ■■Adaptations such as reproductive rates and longevity can best be understood from the per- spective of individual selec ...

SUGGESTioNS FoR FURTHER READiNG The Evolution of Life Histories, by S. C. Stearns (oxford University Press, oxford, 1992), and L ...

12_EVOL4E_CH12.indd 294 3/22/17 2:38 PM ...

Look at an ant nest. It is familiar, yet utterly remarkable. Hundreds to millions of individuals—a mother and her many, many non ...

296 CHAPTER 12 The Costs and benefits of Interacting A useful way to think about the interactions among individuals within a spe ...

CooPERATIoN AND CoNFlICT 297 By analogy, why don’t all ants in a colony reproduce, and why don’t all humans cheat on their taxes ...

298 CHAPTER 12 Reciprocity Robert Trivers suggested that cooperation can evolve when one individual pro- vides a fitness benefit ...