Seasons of Life: The Biological Rhythms That Enable Living Things to Thrive and Survive
Russell G. Foster
Format: PDF / Kindle (mobi) / ePub
Just as daily events are timed by living creatures through circadian rhythms, so seasonal events are timed through an internal calendar that signals birds to return to nesting grounds, salmon to spawn, plants to flower, squirrels to hibernate, kelp to stop growing.
In this fascinating book, Russell G. Foster and Leon Kreitzman draw on remarkable recent scientific advances to explain how seasonal change affects organisms, and how plants and animals over countless generations have evolved exquisite sensitivities and adaptations to the seasons. The authors also highlight the impact of seasonal change on human health and well-being. They conclude with a discussion of the dangers posed when climate changes disrupt the seasonal rhythms on which so much life depends.
Surprising facts from Seasons of Life:
–The timing of human birth has a small but significant effect on various later life attributes, such as handedness and the susceptibility to many illnesses, including multiple sclerosis and schizophrenia.
–Plants have the ability to measure the length of a period of light, and they germinate, flower, and successfully reproduce by using this information.
–Birds migrate not in response to weather changes but by using an internal calendar.
–Until recently, human birth was tightly coupled to the seasons, peaking in many societies in the spring.
–Just as internal 24-hour circadian clocks predict daily change, many animals have a circannual clock in their brains that predicts the seasons.
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plants and animals. This close affinity to nature has been lost by most of us in the developed world, although there are still a handful of those who can tell the species of a tree by the sound it makes as the wind blows through. In Chapter 3 we move into the first of the four sections detailing the mechanisms used by plants and animals to anticipate seasonal change, and we start with plants. Although few of the readers of this book will be farmers, many will be gardeners. They know that some
production (Klein et al., 1983). Although it became clear that the profile of melatonin released from the pineal encodes the daylength signal and that the melatonin profile alone can regulate the cascade of hormonal activity of the reproductive system, the question became one of how it was done. What was the link between photoperiod, melatonin and the reproductive system? The link is in the pituitary gland. The pituitary is an endocrine gland that regulates much of mammalian physiology and
the mechanisms of the circadian clock of mammals. But in recent years he has switched the focus of much of his work to understand monarch butterfly migration. He argues that this animal is a possible model for understanding the cellular and molecular mechanisms underlying not only the regulation of migration timing mechanisms but also time-compensated sun-compass navigation (Reppert, 2006). Just eight cells in the monarch butterfly brain near the pars lateralis seem to be the ‘master’ circadian
Alexander the Great in 323 bc. In the 1600s Jesuits brought the anti-malarial cinchona bark, later shown to contain quinine, to Europe, although Oliver Cromwell apparently refused the ‘papist’ remedy and died of malaria for his prejudices. The Nazis deliberately spread malarial infection as they retreated through Italy in the Second World War. Once common – it gets its name from the Italian mala aria (‘bad air’) – the World Health Organization only declared it officially eradicated from that