Here again, males come in three types: orange throats, blue throats, and yellow throats. Genes for exploding males spread through- out the population. A big fight can last for hours in the heat of the African sun and can certainly be fatal In between rounds, fighting elephants uproot trees and throw logs, and if, at the end of all this ing, the fight finishes with the winner chasing the loser for sev- eral miles.
Similar invasions often happen in southern sea lion colonies. Because they are quite big, bowerbirds are easily able to monopolize fruit trees, scattering smaller birds out of their way.
No trivia or quizzes yet. Olivia Judson born is an evolutionary biologist at Imperial College London. In the process, she explains the science behind it all, from Darwin's theory of sexual selection to why sexual reproduction exists at all. Nessa Carey. Buy Book From Amazon.
A couple of days later, the eggs hatched Buy Book From Amazon. Enlarge cover. Those who do not have the gene will die, their genes "deselected" from the population. This was a fun book, and eye-opening! Apparently, without sex you are doomed.
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After six days of sex, the sperm in a ram's ejaculate can fall from more than ten billion to less than fifty million—a threshold below which he'll have a hard time impregnating anybody. Uhm— ahem —", he starts to greet her, to ask how her day has been, but he is also trying gauge his risk, and consider whether he has any escape from her Harlequin beetles are magnificent, their jet-black wing cov- ers decorated with jagged red stripes.
In the rabbit, for example, the number of sperm arriving at any given stage of a female's gen- ital tract depends on how many sperm started out. The tone of the book.